DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Amendment
This office action is responsive to the amendment filed on 09 October 2025. As directed by the amendment: claims 1, 18, 24, 45, 47 & 48 have been amended, and no claims have been cancelled or added. Claims 5, 7, 8, 10, 14-17, 19-23, 26, 27, 30, 32-39 & 41-44 were cancelled by previous amendments. Thus, claims 1-4, 6, 9, 11-13, 18, 24, 25, 28, 29, 31 & 45-48 are presently pending in this application.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claim 47 is rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 47 has been amended to recite “wherein the strip is embedded in an organic and/or an inorganic coating selected from the group consisting of an organic coating, a carbon coating and an aluminum coating”. While the originally filed specification discloses that such a steel strip or titanium strip may preferably comprise an organic and/or inorganic coating (pg. 12, lines 1-6), there does not appear to be sufficient support in the application as originally filed for the strip to be “embedded” in such a coating as is now claimed.
The above cited portion of the specification further explains that the organic coating may be, e.g., a previously mentioned polymer and that the inorganic coating may be carbon and/or aluminum. While the specification thus indirectly suggests that the same polymers in which the steep strip or titanium strip may be embedded (e.g., when provided as a tape, as in fig. 4e) may also be used as a coating for a steel or titanium strip, this does not necessarily support an inverse generalization wherein the steel or titanium strip may be embedded in the disclosed coatings. By way of example, the specification contains no explicit support for the steel or titanium strips to be “embedded” in the carbon or aluminum coatings.
As a result, the claim contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, at the time the application was filed, had possession of the claimed invention.
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-4, 6, 9, 11-13, 18, 24, 25, 28, 29, 31, 45 & 47 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claims 1 & 45 recite “wherein the embedding material is selected from the group comprising PVDF…PEEK…and PVC…”. Note: a similar issue was previously corrected for the “at least one elongate element” groupings, but not for the “embedding material” groupings.
As set forth in MPEP 2173.05(h)(I), a Markush grouping is a closed group of alternatives, i.e., the selection is made from a group "consisting of" (rather than "comprising" or "including") the alternative members.
A claim reciting a Markush grouping which requires a selection from an open list of alternatives (e.g., selected from the group "comprising" or "consisting essentially of" the recited alternatives) is generally rejected under 35 U.S.C. 112(b) as indefinite because it is unclear what other alternatives are intended to be encompassed by the claim.
If a claim is intended to encompass combinations or mixtures of the alternatives set forth in the Markush grouping, the claim may include qualifying language preceding the recited alternatives (such as "at least one member" selected from the group), or within the list of alternatives (such as "or mixtures thereof"). See also MPEP § 2111.03.
Thus, the groups recited in claims 1 & 45 defining the alternative embedding materials must be presented as a closed group (i.e. “consisting of”), but may include qualifying language as noted above.
Claim 24 recites “wherein said at least one elongate element… comprises said strip of steel or titanium embedded in an embedding material”, which raises several issues.
First, as claim 1 recites several constructions with “a strip of steel or titanium” (i.e., “a strip of steel or titanium, a tape of a strip of steel or titanium embedded in an embedding material,… a tape of a strip of steel or titanium and fibers embedded in an embedding material”), it is not necessarily clear which “strip of steel or titanium” corresponds to “said strip of steel or titanium” in claim 24.
As best understood, this limitation was likely intended to require that the at least one elongate element, as defined in claim 1, is limited to the listed construction of a tape comprising “a strip of steel or titanium embedded in an embedding material”, however, claim 24 might instead be seen as attempting to further define the first recited “strip of steel or titanium” (i.e. not embedded as a tape in claim 1) as now being embedded in an embedding material in claim 24.
Alternatively, it is not clear if claim 24 is intended to be limited only to the “tape of a strip of steel or titanium embedded in an embedding material” or if this may also include the “tape of a strip of steel or titanium and fibers embedded in an embedding material”.
It is also unclear if the recitation of “an embedding material” as recited in claim 24 is intended to inherit the same limitations as the embedding material recitations in claim 1 (i.e., it is unclear if the “embedding material” in claim 24 is required to be “selected from the group [consisting of] PVDF… PEEK… and PVC…”).
Claim 47 has been amended to recite “wherein the strip is embedded in an organic and/or an inorganic coating selected from the group consisting of an organic coating, a carbon coating and an aluminum coating”. The originally filed specification disclosed that such a steel strip or titanium strip may comprise an organic and/or inorganic coating (pg. 12, lines 1-6), and, separately, disclosed that a steel strip or titanium strip may be embedded in an embedding material (e.g., fig. 4e; pg. 21, lines 1-5). However, the disclosure does not appear to describe the steel or titanium strips being “embedded” in a “coating”. As a result, claim 47 appears to be conflating the steel or titanium strips being coated in a coating vs being embedded in an embedding material, causing the claim to take on an unreasonable degree of uncertainty.
Claims recited in the section heading above but not specifically discussed are rejected due to dependency upon at least one rejected claim.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-4, 6, 9, 12, 13, 18, 25, 28, 29, 45, 46 & 48 (as understood) are rejected under 35 U.S.C. 103 as being unpatentable over Rytter (US 2008/0283138 A1) in view of Droues (GB 2481175 A) and Demanze (US 2017/0122467; hereafter Demanze ‘467).
Examination Note: Fig. 1 of Rytter appears substantially identical to Fig. 2 of the instant application except for the specific reference numbers.
Regarding claim 1, Rytter discloses (fig. 1) a subsea installation (see para. 4, lines 2-3; para. 7, lines 3-6; abstract, lines 16-17) comprising an unbonded flexible pipe (i.e., as shown in fig. 1) for subsea transportation of a fluid (e.g., liquids or gases such as water, ammonia, or hydrocarbons such as oil or gas; para. 58), the unbonded flexible pipe comprises from inside out, a pressure sheath (4) defining a bore for transportation of the fluid, a pressure armor (5 & 6; para. 76, lines 1-4), a tensile armor (9 & 10; para. 76, lines 4-6) and an outer sheath (14), wherein the tensile armor and the pressure armor are located in an annulus (i.e., an annulus formed between pressure sheath 4 and outer sheath 14) and wherein the tensile armor comprises at least two cross wound layers of elongate armor elements (i.e., 9 & 10, respectively; see opposite winding directions in fig. 1), which are wound with a long pitch (i.e., a short winding angle; see para. 75, lines 14-16: “a relatively smaller winding angle (here between 25° and 60°)”; see also para. 30) and wherein the pipe comprises an anti-bird cage layer (13; see para. 23, lines 1-3) comprising at least one elongate element (i.e., “at least two fibrous cords wound on an underlying layer”, see, e.g., para. 21, lines 11-14) wound with a short pitch (i.e., a large winding angle; see para. 32, the angle of the elongate elements of the anti-bird cage layers are “larger than 70°…in the range from 75° to 90°, such as from 85° to 90°”) onto at least one of the tensile armor layers (as shown in fig. 1, anti-bird cage layer 13 is wound onto tensile armor layer 10 with a thin polymer layer 12 therebetween; see para. 77: the anti-bird cage layer may be wound about tensile armor layer 10 either directly on layer 10 or with the intermediate layer 12 therebetween).
Rytter does not explicitly disclose the limitation wherein said at least one elongate element is selected from the group consisting of a strip of steel or titanium, a tape of a strip of steel or titanium embedded in an embedding material, a tape of fibers embedded in an embedding material, and a tape of a strip of steel or titanium and fibers embedded in an embedding material, wherein the fibers are selected from the group consisting of fibers of stainless steel, fibers of titanium, fibers of carbon, fibers of basalt, and fibers of polyethylene, wherein the embedding material is selected from the group comprising PVDF (polyvinylidene fluoride or polyvinylidene difluoride), PEEK (polyether ether ketone), and PVC (polyvinyl chloride).
However, Rytter does disclose that the elongate elements of the anti-bird cage can be made from a range of materials which, in combination with the selection of the number of filaments in a cord and cross-sectional area, etc., may be used to optimize stiffness of the anti-bird cage layer (para. 36), and suggests that the elongate elements may comprise polymer or co-polymer based fibers, glass fibers or other inorganic fibers (para. 40), or metallic fibers such as steel fibers (para. 41).
Rytter also discloses that it is known to form an anti-bird cage layer as a flat tape comprising a reinforcement material (e.g., aramid fibers) embedded in a carrier material (e.g., polyethylene) which is “formed to a tape of a specific width and thickness” (para. 9-11).
While Rytter suggests that it requires “inappropriately many variants of these tapes to cost effectively manufacture flexible pipes in” (i.e., a wide range of diameters and pressure loads), as set forth in MPEP § 2123(I & II), "The use of patents as references is not limited to what the patentees describe as their own inventions or to the problems with which they are concerned. They are part of the literature of the art, relevant for all they contain." In re Heck, 699 F.2d 1331, 1332-33, 216 USPQ 1038, 1039 (Fed. Cir. 1983) (quoting In re Lemelson, 397 F.2d 1006, 1009, 158 USPQ 275, 277 (CCPA 1968)).
A reference may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art, including nonpreferred embodiments. Merck & Co. v. Biocraft Labs., Inc. 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir. 1989), cert. denied, 493 U.S. 975 (1989).
Disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. In re Susi, 440 F.2d 442, 169 USPQ 423 (CCPA 1971). "A known or obvious composition does not become patentable simply because it has been described as somewhat inferior to some other product for the same use." In re Gurley, 27 F.3d 551, 554, 31 USPQ2d 1130, 1132 (Fed. Cir. 1994).
Thus, Rytter reasonably discloses that the least one elongate element of the anti-bird cage layer may comprise reinforcement fibers embedded in a polymer embedding material to form flat tapes of a desired thickness.
Examination Note: Applicant’s own WO 2018/006919 A1 (cited later in this action as Andersen et al.) appears to admit that Rytter would be understood as disclosing such anti-birdcage layer composite tapes. See pg. 3, lines 19-35: “…an outer armouring layer is sometimes wound at a large angle around the tensile armouring layer(s). This armouring layer is made of very flat profiles in the form of fibre reinforced polymeric tapes and often referred to as a retaining layer….Tapes of this type are e.g. disclosed in US- 2004/0025953 and in WO 2006/005689.”. The aforementioned WO 2006/005689 corresponds to Rytter (i.e., WO 2006/005689 is the publication of PCT/EP2005/053143 to which Rytter claims priority).
Demanze ‘467 teaches (e.g., fig. 1) an unbonded flexible pipe (10) comprising a pressure sheath (16), a pressure armor (18), tensile armor (22, 24), an anti-bird cage layer (30) and an outer sheath (32), wherein the anti-bird cage layer comprises at least one elongate element (28; see figs. 2-4B). In various embodiments, Demanze ‘467 suggests that the at least one elongate element may take the form of a tape comprising inorganic mineral fiber reinforcement strands (36), preferably basalt fiber (para.42), embedded in a polymer matrix (34), as in FIG. 2, but also suggests that other inorganic mineral fibers such as glass fibers, ceramic fibers, and carbon fibers may be suitable (para. 12).
Demanze ‘467 explains that inorganic mineral fibers are more resistant to hydrolysis than organic fibers of the aramid type and are less vulnerable to corrosion than metallic fibers (para. 13).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the subsea installation of Rytter such that the reinforcement fibers of the at least one elongate element comprised fibers of carbon or basalt, in view of the teachings of Demanze ‘467, to provide fibers which are more resistant to hydrolysis than organic (e.g., aramid) fibers and less vulnerable to corrosion (e.g., than metallic fibers), as suggested by Demanze ‘467, especially considering that Rytter already explicitly suggests that “inorganic fibers” may be suitably used to form the elongate elements of the anti-bird cage layer and, further obvious in considering that it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416.
With respect to the polymer matrix embedding material (34), Demanze ‘467 suggests that this could be a thermoplastic or thermosetting polymer material (para. 42, lines 11-12; see also para. 58, lines 6-8; claims 8-11), and further lists (para. 21) several examples of suitable thermoplastics including PEEK (polyether ether ketone) and chlorinated PVC, among others.
It would have been further obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to select, e.g., PEEK (polyether ether ketone), as the polymer embedding material, in view of the teachings of Demanze ‘467, especially considering that it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416.
As set forth in MPEP § 2131, "When a claim covers several structures or compositions, either generically or as alternatives, the claim is deemed anticipated if any of the structures or compositions within the scope of the claim is known in the prior art." Brown v. 3M, 265 F.3d 1349, 1351, 60 USPQ2d 1375, 1376 (Fed. Cir. 2001).
In view of the above, the subsea installation of Rytter, modified such that the at least one elongate element of the anti-bird cage layer is provided as a tape having basalt or carbon fibers embedded in PEEK, reads on or otherwise renders obvious the limitation wherein said at least one elongate element is selected from the group consisting of a strip of steel or titanium, a tape of a strip of steel or titanium embedded in an embedding material, a tape of fibers embedded in an embedding material, and tape of a strip of steel or titanium and fibers embedded in an embedding material, wherein the fibers are selected from the group consisting of fibers of stainless steel, fibers of titanium, fibers of carbon, fibers of basalt, and fibers of polyethylene, wherein the embedding material is selected from the group comprising PVDF (polyvinylidene fluoride or polyvinylidene difluoride), PEEK (polyether ether ketone), and PVC (polyvinyl chloride).
Regarding the limitation wherein the subsea installation / unbonded flexible pipe is “for subsea transportation of a H2S and/or CO2 containing fluid”, as set forth in MPEP § 2115, a claim is only limited by positively recited elements. Thus, the inclusion of the material or article worked upon by a structure being claimed does not impart patentability to the claims.
Additionally, as set forth in MPEP § 2114(II), apparatus claims cover what a device is, not what a device does. A claim containing a recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus if the prior art apparatus teaches all the structural limitations of the claim.
In the instant case, Rytter discloses that the unbonded flexible pipeline is intended for use with hydrocarbons such as oil and gas, and it is well-known that oil and gas may naturally include some amount of H2S and CO2 (e.g., when obtained from “sour” formations). While Rytter does not explicitly disclose that the unbonded flexible pipe is for transporting an “H2S and/or CO2 containing fluid”, the unbonded flexible pipe is understood to be capable of transporting hydrocarbon fluids such as oil and gas which may contain at least some (naturally occurring) concentration of H2S and CO2, in at least- some capacity (i.e., even if the pipe may have a shortened service life under such instances, etc.).
To promote compact prosecution on this issue, an additional teaching in view of Droues is otherwise provided below.
Regarding the limitation wherein the tensile armor and the pressure armor are of stainless steel, Rytter discloses that armor layers, including radial (i.e., pressure) armor layers and tensile armor layers, are conventionally made of steel (para. 8, line 12) and, more broadly, suggests that the armor layers may be made of metallic materials (para. 75, lines 7-9).
Rytter does not explicitly disclose the additional limitation wherein the tensile armor and the pressure armor are of stainless steel, however, this feature is otherwise taught by Droues, as also set forth below.
Droues teaches (fig. 1) an unbonded flexible pipe (22) comprising a pressure armor (14) and a tensile armor (16, 18) located in an annulus between an inner pressure sheath (12) and an outer sheath (20).
Droues explains that the tensile armor layers may be formed from corrosion resistant materials such as hammer-hardened austenitic-ferritic stainless steel (e.g., see abstract) to enable the unbonded flexible pipe to be used as a subsea pipe for transporting hydrocarbons having a high content of corrosive gasses such as H2S and CO2 (pg. 1, lines 4-10). More specifically, the unbonded flexible pipe of Droues is intended to operate, e.g., with “polyphase hydrocarbons having a high H2S partial pressure, typically 0.5 to 4 bar, and/or a high CO2 partial pressure, typically at least 5 bar” which are “generally very acid, their pH typically being less than 4.5”, with temperatures which may exceed 90°C, while at depths of “2000m and greater” (pg. 2, line 28 – pg. 3, line 2; pg. 17, lines 9-12).
Droues also suggests that the pressure armor (14) may, in certain embodiments, also be formed from stainless steel. In particular, Droues suggests that the pressure armor may be formed by “a duplex stainless steel wire…wound around the internal pressure sheath” (pg. 10, lines 13-16), and otherwise explains that “according to another embodiment, it is also envisaged producing the pressure vault 14 with wires made of stainless steel or conventional duplex steel that have undergone little or no work-hardening” (pg. 21, lines 31-34). See also, published claim 10 (“…a duplex stainless steel wire is provided for forming said pressure vault (14)”).
Examination Note: Applicant’s own specification admits that Droues teaches the use of stainless steel for at least the tensile armor (see published para. 14).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the subsea installation unbonded flexible pipe of Rytter such that the tensile armor and the pressure armor are each made of stainless steel (e.g., the tensile armor being formed from a hammer-hardened austenitic-ferritic stainless steel; the pressure armor being formed from a duplex stainless steel which has undergone little or no work-hardening), in view of the teachings of Droues, to enable the unbonded flexible pipe to be used for hydrocarbon bearing formations having a high content of H2S and/or CO2 (i.e., for transportation of a H2S or CO2 containing fluid), as otherwise suggested by Droues, especially considering that it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416.
Examination Note: to promote compact prosecution, it is noted that the use of stainless steel to form armoring layers in unbonded flexible pipes, particularly to improve corrosion resistance when used for deep water / corrosive [H2S] applications, is otherwise known in the art. See, e.g., US 2009/0218093 A1 to Gudme.
Regarding the remaining limitation wherein the annulus is free of carbon steel, the pipe of the subsea installation of Rytter, as modified in view of Demanze ‘467 and Droues above, is seen as reading on this limitation, as explained below.
In the original configuration of Rytter, the annulus (defined between the pressure sheath 4 and the outer sheath 14) comprises the pressure armor (5 & 6), an optional polymeric intermediate anti-friction layer (11), the tensile armor (9 & 10), another optional polymeric intermediate layer (12), and the anti-bird cage layer (13). Thus, when the pressure and tensile armors are formed without carbon steel (e.g., each from stainless steel, in view of Droues) and the anti-bird cage layer is also formed without carbon steel (e.g., as a tape comprising basalt or carbon fibers embedded in PEEK, in view of Demanze ‘467), the resulting combination would read on the limitation wherein the annulus is free of carbon steel.
As a result, all of the limitations of claim 1 are met or are otherwise rendered obvious.
Regarding claim 2, the subsea installation / unbonded flexible pipe of Rytter reads on the additional limitation wherein the pressure sheath (4) and the outer sheath (14) form said annulus.
Regarding claim 3, the subsea installation / unbonded flexible pipe of Rytter, as modified above, reads on the additional limitation wherein the unbonded flexible pipe is arranged for subsea transportation of an acidic crude oil and/or gas at a raised temperature, wherein the raised temperature is at least 30 °C inside the bore of the pipe.
In particular, Rytter discloses that unbonded flexible pipes are used for subsea transport of oil and gas, and are “particularly well suited for the transport of oil from subsea sources to installations at sea level where the oil is being refined or forwarded for further processing” (para. 7; i.e., subsea transportation of crude oil; see also, paras. 4 & 58). Rytter further discloses that such pipes may “be useful in applications such as the transport of fluids at elevated temperatures and or pressures” (para. 3).
As mentioned for claim 1 above, Droues teaches that an unbonded flexible pipe comprising corrosion resistant tensile armor may be used with polyphase hydrocarbons which are “generally very acid” and have a temperature which “may exceed 90°C.” Elsewhere, Droues suggests (pg. 22, line 35 – pg. 23, line 6) that 2205 duplex steel may be used when temperatures in the annulus are below 50° C (which is “rare”) and, for high temperature applications, 2507 superduplex steels may be used. As would be understood by a person having ordinary skill in the art, a temperature of 50°C in the annulus would correspond to a higher temperature in the bore, as the unbonded flexible pipe separates the higher temperature fluid in the bore and the relatively colder seawater outside the pipe.
As a result, the unbonded flexible pipe of Rytter, as modified above, is reasonably seen as being arranged for subsea transportation of an acidic crude oil and/or gas at a raised temperature, wherein the raised temperature is at least of at least 30 °C inside the bore.
Examination Note: to promote compact prosecution, it is noted that US 2009/0218093 A1 to Gudme discloses testing a duplex stainless steel usable for armoring layers in corrosive-service unbonded flexible pipes at a temperature of 130°C.
Regarding claims 4 & 6, with respect to the limitations wherein the unbonded flexible pipe is arranged for subsea transportation of a sour fluid comprising at least 0.5 % by weight of sulfur or comprising at least 100 ppm of H2S (claim 4) and wherein the unbonded flexible pipe is arranged for subsea transportation of fluid containing at least 100 ppm of CO2 or containing at least 10 mol% of CO2 (claim 6), as set forth in MPEP § 2115, the inclusion of the material or article worked upon by a structure being claimed does not impart patentability to the claims.
Additionally, as set forth in MPEP § 2114(II), apparatus claims cover what a device is, not what a device does. A claim containing a recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus if the prior art apparatus teaches all the structural limitations of the claim.
It is further noted that, as best understood, the H2S and CO2 concentration of a sour fluid is generally based on the naturally occurring composition of the hydrocarbon formation and is not dependent on the structure of the pipe. This is reasonably seen as a matter of intended use.
As mentioned in the grounds of rejection for claim 1 above, Droues otherwise suggests that an unbonded flexible pipe comprising corrosion resistant tensile armor may be used with polyphase hydrocarbons which have “a high H2S partial pressure, typically 0.5 bar to 5 bar, and/or a high CO2 partial pressure, typically at least 5 bar”.
As understood, the subsea installation comprising the unbonded flexible pipe of Rytter, as modified in view of Droues, is thus reasonably seen as capable of subsea transportation of a sour fluid comprising at least 0.5 % by weight of sulfur or comprising at least 100 ppm of H2S (as in claim 4) and/or capable of subsea transportation of fluid containing at least 100 ppm of CO2 or containing at least 10 mol% of CO2 (as in claim 6).
Regarding claim 9, with respect to the limitation wherein the pH value in at least a location of the annulus is 4.5 or less, as set forth in MPEP § 2115, the inclusion of the material or article worked upon by a structure being claimed does not impart patentability to the claims.
Additionally, as set forth in MPEP § 2114(II), apparatus claims cover what a device is, not what a device does. A claim containing a recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus if the prior art apparatus teaches all the structural limitations of the claim.
It is further noted that, as best understood, the pH concentration in the annulus is based, at least in part, on the acidity of the transported fluid (which partially diffuses into the annulus). This is reasonably seen as a matter of intended use.
As mentioned in the grounds of rejection for claim 1 above, Droues teaches that an unbonded flexible pipe comprising corrosion resistant tensile armor may be used with polyphase hydrocarbons which are “generally very acid, their pH typically being less than 4.5”.
Droues further explains that work-hardened duplex steels are resistant to acid gases which may diffuse through the pressure sheath (pg. 19, lines 32-36).
Additionally, while Droues explains that, in one favorable embodiment, less expensive duplex steel may be used for the tensile armor if pressure armor is provided as carbon steel to consume a large proportion of any H2S in the annulus by reaction, which prevents a low pH in the annulus (pg. 20, line 27 – pg. 21, line 19), Droues also suggests that the pressure armor may instead be provided as a stainless steel or conventional duplex steel, or omitted entirely, in which case a more expensive (e.g., “top-of-the-range”) duplex steel is preferably used for the tensile armor layers (pg. 21, lines 21-34). As would be recognized by a person having ordinary skill in the art, embodiments which utilize stainless/duplex steel pressure armor would not have the mitigating effect on H2S which diffuses into the annulus, as there is no carbon steel to react with, so the annulus would, as understood, have a low pH, at least under certain conditions.
In view of the above, the subsea unbonded flexible pipe of Rytter, as modified in view of Droues, is reasonably seen as capable of use in conditions wherein the pH value in at least a location of the annulus is 4.5 or less (e.g., when used with a stainless steel pressure armor, as suggested by Droues and as described for the rejection of claim 1 above).
Examination Note: to promote compact prosecution, it is noted that US 2009/0218093 A1 to Gudme discloses testing a duplex stainless steel usable for armoring layers in corrosive-service unbonded flexible pipes at a pH of 4.0.
Regarding claim 12, the subsea installation / unbonded flexible pipe of Rytter, as modified above, reads on the additional limitation wherein at least a length section of the unbonded flexible pipe is located at least 100 m below sea surface.
In particular, Rytter suggests that such pipes may be configured for use below sea level down to, e.g., 2000 m of depth (para. 11, lines 14-16).
Similarly, Droues suggests that an unbonded flexibly pipe having corrosion resistant tensile armor may be intended to operate at “very great depth, 2000 m and greater” (pg. 2, lines 32-33).
In view of the above, Rytter and/or Droues are reasonably seen suggesting use of such an unbonded flexible pipe in conditions wherein at least a length section of the unbonded flexible pipe is located at least 100 m below sea surface.
Examination Note: to promote compact prosecution, it is noted that US 2009/0218093 A1 to Gudme discloses a duplex stainless steel usable for armoring layers in corrosive-service unbonded flexible pipes at depths which may be deeper than 1500 meters.
Regarding claim 13, Rytter further discloses the additional limitation wherein the at least one elongate element of the anti-bird cage layer (13) is wound with an angle of at least 65° to the center axis of the unbonded flexible pipe (see para. 32, the angle of the elongate elements of the anti-bird cage layers are “larger than 70°…in the range from 75° to 90°, such as from 85° to 90°”).
Regarding claim 18, the subsea installation / unbonded flexible pipe of Rytter, as modified above, reads on or otherwise renders obvious the limitation wherein the at least one elongate element of the anti-bird cage layer is in the form of a flat tape.
As previously noted, Rytter explains that it is known to form the at least one elongate element of the anti-bird cage layer as “a tape of a specific width and thickness” (para. 11), however, Rytter does not explicitly disclose that the thickness may be from 0.2 mm to 3 mm.
Demanze ‘467 teaches that the embedding material / polymer material of such an elongate element of an anti-bird cage layer may take the form of a flat tape (i.e., a “holding strip” as shown), and further suggests that this tape / holding strip may have “a thickness between, for example, 0.05mm and 5mm” (para. 42, lines 5-8).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the subsea installation of Rytter such that at least one elongate element of the anti-bird cage layer is provided in the form of a flat tape with a thickness in the range from 0.2 mm to 3 mm, in view of the teachings of Demanze ‘467, as Rytter discloses that anti-bird cage layers having fibers embedded in a carrier material may be formed as flat tapes with “a specific…thickness”, and Demanze ‘467 teaches a corresponding range of suitable thicknesses for such a flat tape for an anti-bird cage layer may be between 0.05mm and 5mm, encompassing the claimed range of 0.2 mm to 3mm.
As set forth in MPEP § 2144.05(I), in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists.
Regarding claim 25, Rytter discloses the additional limitation wherein the unbonded flexible pipe comprises two or more anti-bird cage layers (13).
In particular, FIG. 1 reasonably shows anti-bird cage layer 13 formed as two layers; alternate embodiments in figs. 2D & 2F are explicitly disclosed as depicting two anti-bird cage layers, and fig. 2E is disclosed as depicting three such layers (see para. 78, lines 5-14).
Regarding claim 28, Rytter discloses the additional limitation wherein the anti-bird cage layer (13) is located in the annulus in physical contact with at least one of the tensile armor layers (9,10).
In particular, Fig. 1 of Rytter clearly shows the anti-bird cage layer 13 as being located within the annulus (defined between pressure sheath 4 and outer sheath 14), but is shown with a thin polymer layer 12 between the anti-bird cage layer 13 and the outermost tensile armor layer 10. However, Rytter explicitly discloses (para. 77, lines 8-9) that, alternatively, anti-bird cage layer 13 “may be wound directly on the underlying armouring layer”.
Regarding claim 29, Rytter discloses the additional limitation wherein the unbonded flexible pipe further comprises a stabilization layer (12) located outside the tensile armor layers and wherein the anti-bird cage layer (13) is located onto and in contact with said stabilization layer (as shown in fig. 1), and wherein the stabilization layer is made from wound polymeric strips (see para. 75, lines 21-24: “a polymer based layer (here comprising wound polymer based tape) 12 may be applied around the outermost 10 of the additional armouring layers.”).
Regarding the limitation wherein the wound polymeric strips are helically wound polymeric strips, a person having ordinary skill in the art before the effective filing date would have understood that the disclosure of “wound polymeric strips” in this context would reasonably have meant helically wound strips, or otherwise reasonably encompassed embodiments comprising helically wound strips, especially considering that each of the other wound layers disclosed by Rytter (e.g., 2, 5, 6, 9, 10, 13) are helically wound at an angle (i.e., Rytter does not explicitly disclose any circumferentially / ring wound elements).
As set forth in MPEP § 2144.01, "[I]n considering the disclosure of a reference, it is proper to take into account not only specific teachings of the reference but also the inferences which one skilled in the art would reasonably be expected to draw therefrom." In re Preda, 401 F.2d 825, 826, 159 USPQ 342, 344 (CCPA 1968).
See also MPEP § 2131.02(III), a reference disclosure can anticipate a claim when the reference describes the limitations but "'d[oes] not expressly spell out' the limitations as arranged or combined as in the claim, if a person of skill in the art, reading the reference, would ‘at once envisage’ the claimed arrangement or combination." Kennametal, Inc. v. Ingersoll Cutting Tool Co., 780 F.3d 1376, 1381, 114 USPQ2d 1250, 1254 (Fed. Cir. 2015) (quoting In re Petering, 301 F.2d 676, 681(CCPA 1962)).
However, to promote compact prosecution on this issue, an alternative rejection in view of Demanze (WO 2015/082865 A1) is provided later in this action.
Regarding claim 45, Rytter discloses (fig. 1) an unbonded flexible pipe for subsea transportation (see para. 4, lines 2-3; para. 7, lines 3-6; abstract, lines 16-17) of a fluid (e.g., liquids or gases such as water, ammonia, or hydrocarbons such as oil or gas; para. 58), the unbonded flexible pipe comprises from inside out, a pressure sheath (4) defining a bore for transportation of the fluid, a pressure armor (5 & 6; para. 76, lines 1-4), a tensile armor (9 & 10; para. 76, lines 4-6) and a liquid impervious outer sheath (14; see para. 5, lines 10-12; para. 61, lines 15-17; para. 75, lines 26-27), wherein the tensile armor and the pressure armor are located in an annulus (i.e., an annulus formed between pressure sheath 4 and outer sheath 14), and the tensile armor comprises at least two cross wound layers of elongate armor elements (i.e., 9 & 10, respectively; see opposite winding directions in fig. 1), which are wound with a long pitch (i.e., a short winding angle; see para. 75, lines 14-16: “a relatively smaller winding angle (here between 25° and 60°)”; see also para. 30) and wherein the pipe further comprises an anti-bird cage layer (13; see para. 23, lines 1-3) comprising at least one elongate element (i.e., “at least two fibrous cords wound on an underlying layer”, see, e.g., para. 21, lines 11-14) wound with a short pitch (i.e., a large winding angle; see para. 32, the angle of the elongate elements of the anti-bird cage layers are “larger than 70°…in the range from 75° to 90°, such as from 85° to 90°”) onto at least one of the tensile armor layers (as shown in fig. 1, anti-bird cage layer 13 is wound onto tensile armor layer 10 with a thin polymer layer 12 therebetween; see para. 77: the anti-bird cage layer may be wound about tensile armor layer 10 either directly on layer 10 or with the intermediate layer 12 therebetween).
Rytter does not explicitly disclose the limitation wherein said at least one elongate element is selected from the group consisting of a strip of steel or titanium, a tape of a strip of steel or titanium embedded in an embedding material, a tape of fibers embedded in an embedding material, and a tape of a strip of steel or titanium and fibers embedded in an embedding material, wherein the fibers are selected from the group consisting of fibers of stainless steel, fibers of titanium, fibers of carbon, fibers of basalt, and fibers of polyethylene, and wherein the embedding material is selected from the group comprising PVDF (polyvinylidene fluoride or polyvinylidene difluoride), PEEK (polyether ether ketone), and PVC (polyvinyl chloride).
However, Rytter does disclose that the elongate elements of the anti-bird cage can be made from a range of materials which, in combination with the selection of the number of filaments in a cord and cross-sectional area, etc., may be used to optimize stiffness of the anti-bird cage layer (para. 36), and suggests that the elongate elements may comprise polymer or co-polymer based fibers, glass fibers or other inorganic fibers (para. 40), or metallic fibers such as steel fibers (para. 41).
Rytter also discloses that it is known to form an anti-bird cage layer as a flat tape comprising a reinforcement material (e.g., aramid fibers) embedded in a carrier material (e.g., polyethylene) which is “formed to a tape of a specific width and thickness” (para. 9-11).
While Rytter suggests that it requires “inappropriately many variants of these tapes to cost effectively manufacture flexible pipes in” (i.e., a wide range of diameters and pressure loads), as set forth in MPEP § 2123(I & II), "The use of patents as references is not limited to what the patentees describe as their own inventions or to the problems with which they are concerned. They are part of the literature of the art, relevant for all they contain." In re Heck, 699 F.2d 1331, 1332-33, 216 USPQ 1038, 1039 (Fed. Cir. 1983) (quoting In re Lemelson, 397 F.2d 1006, 1009, 158 USPQ 275, 277 (CCPA 1968)).
A reference may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art, including nonpreferred embodiments. Merck & Co. v. Biocraft Labs., Inc. 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir. 1989), cert. denied, 493 U.S. 975 (1989).
Disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. In re Susi, 440 F.2d 442, 169 USPQ 423 (CCPA 1971). "A known or obvious composition does not become patentable simply because it has been described as somewhat inferior to some other product for the same use." In re Gurley, 27 F.3d 551, 554, 31 USPQ2d 1130, 1132 (Fed. Cir. 1994).
Thus, Rytter reasonably discloses that the least one elongate element of the anti-bird cage layer may comprise reinforcement fibers embedded in a polymer embedding material to form flat tapes of a desired thickness.
Examination Note: Applicant’s own WO 2018/006919 A1 (cited later in this action as Andersen et al.) appears to admit that Rytter would be understood as disclosing such anti-birdcage layer composite tapes. See pg. 3, lines 19-35: “…an outer armouring layer is sometimes wound at a large angle around the tensile armouring layer(s). This armouring layer is made of very flat profiles in the form of fibre reinforced polymeric tapes and often referred to as a retaining layer….Tapes of this type are e.g. disclosed in US- 2004/0025953 and in WO 2006/005689.”. The aforementioned WO 2006/005689 corresponds to Rytter (i.e., WO 2006/005689 is the publication of PCT/EP2005/053143 to which Rytter claims priority).
Demanze ‘467 teaches (e.g., fig. 1) an unbonded flexible pipe (10) comprising a pressure sheath (16), a pressure armor (18), tensile armor (22, 24), an anti-bird cage layer (30) and an outer sheath (32), wherein the anti-bird cage layer comprises at least one elongate element (28; see figs. 2-4B). In various embodiments, Demanze ‘467 suggests that the at least one elongate element may take the form of a strip (i.e., a tape) comprising inorganic mineral fiber reinforcement strands (36), preferably basalt fiber (para.42), embedded in a polymer matrix (34), as in FIG. 2, but also suggests that other inorganic mineral fibers such as glass fibers, ceramic fibers, and carbon fibers may be suitable (para. 12).
Demanze ‘467 explains that inorganic mineral fibers are more resistant to hydrolysis than organic fibers of the aramid type and are less vulnerable to corrosion than metallic fibers (para. 13).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the unbonded flexible pipe of Rytter such that the reinforcement fibers of the at least one elongate element comprised fibers of carbon or basalt, in view of the teachings of Demanze ‘467, to provide fibers which are more resistant to hydrolysis than organic (e.g., aramid) fibers and less vulnerable to corrosion (e.g., than metallic fibers), as suggested by Demanze ‘467, especially considering that Rytter already explicitly suggests that “inorganic fibers” may be suitably used to form the elongate elements of the anti-bird cage layer and, further obvious in considering that it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416.
With respect to the polymer matrix embedding material (34), Demanze ‘467 suggests that this could be a thermoplastic or thermosetting polymer material (para. 42, lines 11-12; see also para. 58, lines 6-8; claims 8-11), and further lists (para. 21) several examples of suitable thermoplastics including PEEK (polyether ether ketone) and chlorinated PVC, among others.
It would have been further obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to select, e.g., PEEK (polyether ether ketone), as the polymer embedding material, in view of the teachings of Demanze ‘467, especially considering that it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416.
As set forth in MPEP § 2131, "When a claim covers several structures or compositions, either generically or as alternatives, the claim is deemed anticipated if any of the structures or compositions within the scope of the claim is known in the prior art." Brown v. 3M, 265 F.3d 1349, 1351, 60 USPQ2d 1375, 1376 (Fed. Cir. 2001).
In view of the above, the unbonded flexible pipe of Rytter, modified such that the at least one elongate element of the anti-bird cage layer comprises basalt or carbon fibers embedded in PEEK, reads on or otherwise renders obvious the limitation wherein said at least one elongate element is selected from the group consisting of a strip of steel or titanium, a tape of a strip of steel or titanium embedded in an embedding material, a tape of fibers embedded in an embedding material, and a tape of a strip of steel or titanium and fibers embedded in an embedding material, wherein the fibers are selected from the group consisting of fibers of stainless steel, fibers of titanium, fibers of carbon, fibers of basalt, and fibers of polyethylene, wherein the embedding material is selected from the group comprising PVDF (polyvinylidene fluoride or polyvinylidene difluoride), PEEK (polyether ether ketone), and PVC (polyvinyl chloride).
Regarding the limitation wherein the unbonded flexible pipe is “for subsea transportation of a H2S and/or CO2 containing fluid”, as set forth in MPEP § 2115, a claim is only limited by positively recited elements. Thus, the inclusion of the material or article worked upon by a structure being claimed does not impart patentability to the claims.
Additionally, as set forth in MPEP § 2114(II), apparatus claims cover what a device is, not what a device does. A claim containing a recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus if the prior art apparatus teaches all the structural limitations of the claim.
In the instant case, Rytter discloses that the unbonded flexible pipeline is intended for use with hydrocarbons such as oil and gas, and it is well-known that oil and gas may naturally include some amount of H2S and CO2 (e.g., when obtained from “sour” formations). While Rytter does not explicitly disclose that the unbonded flexible pipe is for transporting an “H2S and/or CO2 containing fluid”, the unbonded flexible pipe is understood to be capable of transporting hydrocarbon fluids such as oil and gas which may contain at least some (naturally occurring) concentration of H2S and CO2, in at least- some capacity (i.e., even if the pipe may have a shortened service life under such instances, etc.).
To promote compact prosecution on this issue, an additional teaching in view of Droues is otherwise provided below.
Regarding the limitation wherein the tensile armor and the pressure armor are of stainless steel, Rytter discloses that armor layers, including radial (i.e., pressure) armor layers and tensile armor layers, are conventionally made of steel (para. 8, line 12) and, more broadly, suggests that the armor layers may be made of metallic materials (para. 75, lines 7-9).
Rytter does not explicitly disclose the additional limitation wherein the tensile armor and the pressure armor are of stainless steel, however, this feature is otherwise taught by Droues, as also set forth below.
Droues teaches (fig. 1) an unbonded flexible pipe (22) comprising a pressure armor (14) and a tensile armor (16, 18) located in an annulus between an inner pressure sheath (12) and an outer sheath (20).
Droues explains that the tensile armor layers may be formed from corrosion resistant materials such as hammer-hardened austenitic-ferritic stainless steel (e.g., see abstract) to enable the unbonded flexible pipe to be used as a subsea pipe for transporting hydrocarbons having a high content of corrosive gasses such as H2S and CO2 (pg. 1, lines 4-10). More specifically, the unbonded flexible pipe of Droues is intended to operate, e.g., with “polyphase hydrocarbons having a high H2S partial pressure, typically 0.5 to 4 bar, and/or a high CO2 partial pressure, typically at least 5 bar” which are “generally very acid, their pH typically being less than 4.5”, with temperatures which may exceed 90°C, while at depths of “2000m and greater” (pg. 2, line 28 – pg. 3, line 2; pg. 17, lines 9-12).
Droues also suggests that the pressure armor (14) may, in certain embodiments, also be formed from stainless steel. In particular, Droues suggests that the pressure armor may be formed by “a duplex stainless steel wire…wound around the internal pressure sheath” (pg. 10, lines 13-16), and otherwise explains that “according to another embodiment, it is also envisaged producing the pressure vault 14 with wires made of stainless steel or conventional duplex steel that have undergone little or no work-hardening” (pg. 21, lines 31-34). See also, published claim 10 (“…a duplex stainless steel wire is provided for forming said pressure vault (14)”).
Examination Note: Applicant’s own specification admits that Droues teaches the use of stainless steel for at least the tensile armor (see published para. 14).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the unbonded flexible pipe of Rytter such that the tensile armor and the pressure armor are each made of stainless steel (e.g., the tensile armor being formed from a hammer-hardened austenitic-ferritic stainless steel; the pressure armor being formed from a duplex stainless steel which has undergone little or no work-hardening), in view of the teachings of Droues, to enable the unbonded flexible pipe to be used for hydrocarbon bearing formations having a high content of H2S and/or CO2 (i.e., for transportation of a H2S or CO2 containing fluid), as otherwise suggested by Droues, especially considering that it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416.
Examination Note: to promote compact prosecution, it is noted that the use of stainless steel to form armoring layers in unbonded flexible pipes, particularly to improve corrosion resistance when used for deep water / corrosive [H2S] applications, is otherwise known in the art. See, e.g., US 2009/0218093 A1 to Gudme.
Regarding the remaining limitation wherein the annulus is free of carbon steel, the pipe of Rytter, as modified in view of Demanze ‘467 and Droues above, is seen as reading on this limitation, as explained below.
In the original configuration of Rytter, the annulus (defined between the pressure sheath 4 and the outer sheath 14) comprises the pressure armor (5 & 6), an optional polymeric intermediate anti-friction layer (11), the tensile armor (9 & 10), another optional polymeric intermediate layer (12), and the anti-bird cage layer (13). Thus, when the pressure and tensile armors are formed from stainless steel (i.e., each from stainless steel, in view of Droues) and the anti-bird cage layer is formed without carbon steel (i.e., as a tape comprising basalt or carbon fibers embedded in PEEK, in view of Demanze ‘467), the resulting combination reads on the limitation wherein the annulus is free of carbon steel.
As a result, all of the limitations of claim 45 are met or are otherwise rendered obvious.
Regarding claim 46, Rytter discloses (fig. 1) a subsea installation (see para. 4, lines 2-3; para. 7, lines 3-6; abstract, lines 16-17) comprising an unbonded flexible pipe (i.e., as shown in fig. 1) for subsea transportation of a fluid (e.g., liquids or gases such as water, ammonia, or hydrocarbons such as oil or gas; para. 58), the unbonded flexible pipe comprises from inside out, a pressure sheath (4) defining a bore for transportation of the fluid, a tensile armor (9 & 10; para. 76, lines 4-6), and an outer sheath (14), wherein the tensile armor is located in an annulus (i.e., an annulus formed between pressure sheath 4 and outer sheath 14) and the tensile armor comprises at least two cross wound layers of elongate armor elements (i.e., 9 & 10, respectively; see opposite winding directions in fig. 1), which are wound with a long pitch (i.e., a short winding angle; see para. 75, lines 14-16: “a relatively smaller winding angle (here between 25° and 60°)”; see also para. 30) and wherein the pipe further comprises an anti-bird cage layer (13; see para. 23, lines 1-3) comprising at least one elongate element (i.e., “at least two fibrous cords wound on an underlying layer”, see, e.g., para. 21, lines 11-14) wound with a short pitch (i.e., a large winding angle; see para. 32, the angle of the elongate elements of the anti-bird cage layers are “larger than 70°…in the range from 75° to 90°, such as from 85° to 90°”)) onto at least one of the tensile armor layers (as shown in fig. 1, anti-bird cage layer 13 is wound onto tensile armor layer 10 with a thin polymer layer 12 therebetween; see para. 77: the anti-bird cage layer may be wound about tensile armor layer 10 either directly on layer 10 or with the intermediate layer 12 therebetween).
Rytter also discloses a pressure armor (5 & 6; para. 76, lines 1-4) between the pressure sheath and the tensile armor.
Regarding the limitation wherein said at least one elongate element comprises at least one of a strip or a tape, wherein the strip comprises a steel strip or a titanium strip and/or wherein the tape comprises twisted or untwisted continuous fibers embedded in an embedding material, wherein the continuous fibers are arranged to have their length orientated parallel with a length L of the elongate element, Rytter discloses that it is known to form an anti-bird cage layer with a flat tape comprising reinforcement fiber material (e.g., polyaromatic / aramid fibers) which are assembled into “cords” and subsequently embedded in a carrier material (e.g., polyethylene) which is “formed to a tape of a specific width and thickness” (para. 9-11). Rytter also defines the term “cord” as referring to “the product formed by twisting together two or more plied yarns” (para. 16), and defines the term “yarn” as “a generic term for a continuous strand of textile fibers, filaments, or material in a form suitable for twisting, braiding or otherwise intertwining to form a fibrous cord” (para. 15).
While Rytter suggests that it requires “inappropriately many variants of these tapes to cost effectively manufacture flexible pipes in” (i.e., a wide range of diameters and pressure loads), as set forth in MPEP § 2123(I & II), "The use of patents as references is not limited to what the patentees describe as their own inventions or to the problems with which they are concerned. They are part of the literature of the art, relevant for all they contain." In re Heck, 699 F.2d 1331, 1332-33, 216 USPQ 1038, 1039 (Fed. Cir. 1983) (quoting In re Lemelson, 397 F.2d 1006, 1009, 158 USPQ 275, 277 (CCPA 1968)).
A reference may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art, including nonpreferred embodiments. Merck & Co. v. Biocraft Labs., Inc. 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir. 1989), cert. denied, 493 U.S. 975 (1989).
Disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. In re Susi, 440 F.2d 442, 169 USPQ 423 (CCPA 1971). "A known or obvious composition does not become patentable simply because it has been described as somewhat inferior to some other product for the same use." In re Gurley, 27 F.3d 551, 554, 31 USPQ2d 1130, 1132 (Fed. Cir. 1994).
Thus, Rytter reasonably discloses that said at least one elongate element may comprise at least one tape, wherein the tape comprises twisted or untwisted continuous fibers (i.e., a cord of reinforcement material fibers) embedded in an embedding material (e.g., polyethylene).
Examination Note: Applicant’s own WO 2018/006919 A1 (cited later in this action as Andersen et al.) appears to admit that Rytter would be understood as disclosing such anti-birdcage layer composite tapes. See pg. 3, lines 19-35: “…an outer armouring layer is sometimes wound at a large angle around the tensile armouring layer(s). This armouring layer is made of very flat profiles in the form of fibre reinforced polymeric tapes and often referred to as a retaining layer….Tapes of this type are e.g. disclosed in US- 2004/0025953 and in WO 2006/005689.”. The aforementioned WO 2006/005689 corresponds to Rytter (i.e., WO 2006/005689 is the publication of PCT/EP2005/053143 to which Rytter claims priority).
While a person of ordinary skill in the art would at once envisage that such continuous fibers could be arranged to have their length oriented parallel with a length L of the elongate element (i.e., to provide tensile reinforcement, as is well known in the art), Rytter does not explicitly state this arrangement. To promote compact prosecution on this issue, the following additional teaching is provided.
Demanze ‘467 teaches (e.g., fig. 1) an unbonded flexible pipe (10) comprising a pressure sheath (16), a pressure armor (18), tensile armor (22, 24), an anti-bird cage layer (30) and an outer sheath (32), wherein the anti-bird cage layer comprises at least one elongate element (28; see figs. 2-4B). In various embodiments, Demanze ‘467 suggests that the at least one elongate element may take the form of a strip (i.e., a tape) comprising continuous twisted or untwisted inorganic mineral fiber reinforcement strands (36), preferably basalt fiber (para.42), embedded in a polymer matrix (34) embedding material, as in FIG. 2, but also suggests that other inorganic mineral fibers such as glass fibers, ceramic fibers, and carbon fibers may be suitable (para. 12).
Demanze ‘467 further teaches that the embedded fiber strands “extend longitudinally” (para. 41), and otherwise suggests that they may be “of the unidirectional fiber type…stretched longitudinally in the direction of the holding strip 28” (para. 42). In other words, Demanze ‘467 reasonably teaches that the continuous fibers may be arranged to have their length oriented parallel with a length L of the elongate element.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to arrange the continuous fibers embedded within the embedding material to have their length oriented parallel with a length L of the elongate element, in view of the teachings of Demanze ‘467, to enable the fibers to provide their tensile reinforcement properties in a direction substantially parallel with the length of the at least one elongate element as is otherwise well-known in the art.
The above modification would have otherwise been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention as the use of a known technique (i.e., providing embedded reinforcement fibers embedded in a polymer tape as longitudinally arranged, unidirectional reinforcement fibers, as in Demanze ‘467) to improve a similar device (i.e., the unbonded flexible pipe of Rytter) in the same way (e.g., providing substantially longitudinal reinforcement along the tape).
Regarding the limitation wherein the subsea installation / unbonded flexible pipe is “for subsea transportation of a H2S and/or CO2 containing fluid”, as set forth in MPEP § 2115, a claim is only limited by positively recited elements. Thus, the inclusion of the material or article worked upon by a structure being claimed does not impart patentability to the claims.
Additionally, as set forth in MPEP § 2114(II), apparatus claims cover what a device is, not what a device does. A claim containing a recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus if the prior art apparatus teaches all the structural limitations of the claim.
In the instant case, Rytter discloses that the unbonded flexible pipeline is intended for use with hydrocarbons such as oil and gas, and it is well-known that oil and gas may naturally include some amount of H2S and CO2 (e.g., when obtained from “sour” formations). While Rytter does not explicitly disclose that the unbonded flexible pipe is for transporting an “H2S and/or CO2 containing fluid”, the unbonded flexible pipe is understood to be capable of transporting hydrocarbon fluids such as oil and gas which may contain at least some (naturally occurring) concentration of H2S and CO2, in at least some capacity (i.e., even if the pipe may have a shortened service life under such instances, etc.).
To promote compact prosecution on this issue, an additional teaching in view of Droues is otherwise provided below.
Regarding the limitation wherein the tensile armor is of stainless steel, Rytter discloses that armor layers, including radial (i.e., pressure) armor layers and tensile armor layers, are conventionally made of steel (para. 8, line 12) and, more broadly, suggests that the armor layers may be made of metallic materials (para. 75, lines 7-9).
Rytter does not explicitly disclose the additional limitation wherein the tensile armor is of stainless steel, however, this feature is otherwise taught by Droues, as also set forth below.
Droues teaches (fig. 1) an unbonded flexible pipe (22) comprising a pressure armor (14) and a tensile armor (16, 18) located in an annulus between an inner pressure sheath (12) and an outer sheath (20).
Droues explains that the tensile armor layers may be formed from corrosion resistant materials such as hammer-hardened austenitic-ferritic stainless steel (e.g., see abstract) to enable the unbonded flexible pipe to be used as a subsea pipe for transporting hydrocarbons having a high content of corrosive gasses such as H2S and CO2 (pg. 1, lines 4-10). More specifically, the unbonded flexible pipe of Droues is intended to operate, e.g., with “polyphase hydrocarbons having a high H2S partial pressure, typically 0.5 to 4 bar, and/or a high CO2 partial pressure, typically at least 5 bar” which are “generally very acid, their pH typically being less than 4.5”, with temperatures which may exceed 90°C, while at depths of “2000m and greater” (pg. 2, line 28 – pg. 3, line 2; pg. 17, lines 9-12).
Droues also suggests that the pressure armor (14) may, in certain embodiments, also be formed from stainless steel. In particular, Droues suggests that the pressure armor may be formed by “a duplex stainless steel wire…wound around the internal pressure sheath” (pg. 10, lines 13-16), and otherwise explains that “according to another embodiment, it is also envisaged producing the pressure vault 14 with wires made of stainless steel or conventional duplex steel that have undergone little or no work-hardening” (pg. 21, lines 31-34). See also, published claim 10 (“…a duplex stainless steel wire is provided for forming said pressure vault (14)”).
Examination Note: Applicant’s own specification admits that Droues teaches the use of stainless steel for at least the tensile armor (see published para. 14).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the subsea installation unbonded flexible pipe of Rytter such that the tensile armor and the pressure armor are each made of stainless steel (e.g., the tensile armor being formed from a hammer-hardened austenitic-ferritic stainless steel; the pressure armor being formed from a duplex stainless steel which has undergone little or no work-hardening), in view of the teachings of Droues, to enable the unbonded flexible pipe to be used for hydrocarbon bearing formations having a high content of H2S and/or CO2 (i.e., for transportation of a H2S or CO2 containing fluid), as otherwise suggested by Droues, especially considering that it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416.
Examination Note: to promote compact prosecution, it is noted that the use of stainless steel to form armoring layers in unbonded flexible pipes, particularly to improve corrosion resistance when used for deep water / corrosive [H2S] applications, is otherwise known in the art. See, e.g., US 2009/0218093 A1 to Gudme.
Regarding the remaining limitation wherein the annulus is free of carbon steel, the pipe of the subsea installation of Rytter, as modified in view of Demanze ‘467 and Droues above, is seen as reading on this limitation, as explained below.
In the original configuration of Rytter, the annulus (defined between the pressure sheath 4 and the outer sheath 14) comprises the pressure armor (5 & 6), an optional polymeric intermediate anti-friction layer (11), the tensile armor (9 & 10), another optional polymeric intermediate layer (12), and the anti-bird cage layer (13). Thus, when the pressure and tensile armors are formed from stainless steel (i.e., in view of Droues) and the anti-bird cage layer is formed without carbon steel (i.e., as a tape comprising, e.g., polymeric or inorganic [basalt or carbon] reinforcing fibers embedded in a polymer tape, in view of Demanze ‘467), the resulting combination reads on the limitation wherein the annulus is free of carbon steel.
As a result, all of the limitations of claim 46 are met or are otherwise rendered obvious.
Regarding claim 48, the subsea installation of Rytter (as modified above) reads on the limitation wherein said at least one elongate element comprises a tape (see rejection for claim 46 above) and, as previously noted, Rytter discloses (para. 9-11; 15 & 16) that is known to provide the continuous fibers embedded in the embedding material (i.e., the tape) in the form of cords (“…a given reinforcement material, e.g., polyaromatic (aramide) fibers in a certain number are assembled to cords, which subsequently are embedded in a carrier material…”; para. 11).
Rytter further discloses that the embedding material may be a polymer (e.g., polyethylene), however, Rytter does not explicitly disclose the additional limitation wherein the embedding material is selected from the group consisting of PVDF (polyvinylidene fluoride or polyvinylidene difluoride), PEEK (polyether ether ketone) and PVC (polyvinyl chloride).
Demanze ‘467 teaches that such a polymer matrix embedding material (34) could be a thermoplastic or thermosetting polymer material (para. 42, lines 11-12; see also para. 58, lines 6-8; claims 8-11), and further lists (para. 21) several examples of suitable thermoplastics including PEEK (polyether ether ketone) and chlorinated PVC, among others.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to select, e.g., PEEK (polyether ether ketone), as the polymer embedding material, in view of the teachings of Demanze ‘467, especially considering that it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416.
Claim 11 (as understood) is rejected under 35 U.S.C. 103 as being unpatentable over Rytter in view of Droues and Demanze ‘467 as applied to claim 1 above, and further in view of Glejbol et al. (US 2014/0124078 A1; hereafter Glejbol).
Regarding claim 11, with respect to the limitation wherein the fluid is a CO2 containing injection fluid and the unbonded flexible pipe is arranged for transporting the injection fluid at least a part of a way from a sea surface installation to a seabed installation, as set forth in MPEP § 2115, the inclusion of the material or article worked upon by a structure being claimed does not impart patentability to the claims.
Additionally, as set forth in MPEP § 2114(II), apparatus claims cover what a device is, not what a device does. A claim containing a recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus if the prior art apparatus teaches all the structural limitations of the claim.
However, to promote compact prosecution, it is noted that Rytter discloses that the unbonded flexible pipe is “useful in terrestrial and/or subsea transport of fluids at elevated temperature and/or pressures” (abstract, line 17; see also, para. 3), “for marine applications such as the transport of oil or gas or other fluids in a sub-sea environment” (para. 4); “particularly well suited for the transport of oil from subsea sources to installations at sea level where the oil is being refined or forwarded for further processing.” (para. 7); and “the use is for the transport of fluids in the form of liquids or gases, such as water, ammonia, hydrocarbons, such as oil or gas above or below sea level.” (para. 58).
In view of the above, Rytter clearly suggests that the unbonded flexible pipe may be used to transfer a variety of fluids (liquids and/or gases) in a range subsea of applications.
As otherwise mentioned in the grounds of rejection for claim 1, above, Droues teaches that an unbonded flexible pipe having corrosion resistant tensile armor may be used to transport acidic / corrosive fluids (e.g., hydrocarbons), such as those having a high CO2 partial pressure (pg. 2, lines 34-38).
Rytter and Droues do not explicitly disclose that the unbonded flexible pipe may be arranged for transporting a CO2 containing injection fluid at least a part of a way from a sea surface installation to a seabed installation.
Glejbol teaches (throughout) an unbonded flexible pipe for subsea fluid transfer (“for example for transporting of water or of aggressive fluids, such as petrochemical products, e.g., from a production well to a sea surface installation” (para. 1). Glejbol further teaches that such an unbonded flexible pipe may be “adapted for transport of CO2 in liquid and/or supercritical state – i.e., under high pressure” (para. 28), “adapted for injection [of] fluid into the well.” (para. 29), “adapted for use as a carbon dioxide injection riser” (para. 30).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the subsea installation of Rytter such that the fluid is a CO2 containing injection fluid and the unbonded flexible pipe is arranged for transporting the injection fluid at least part of the way from a sea surface installation to a seabed installation (i.e., using the unbonded flexible pipe as a subsea CO2 injection riser transporting liquid and/or supercritical CO2), in view of the teachings of Glejbol, with a reasonable expectation of success, especially considering that Rytter explicitly suggests that the unbonded flexible pipe thereof may be useful for transport of fluids (liquids and/or gases) in a range subsea of applications, and Glejbol similarly suggests that an unbonded flexible pipe for subsea fluid transfer may be adapted for transport of liquid and/or supercritical CO2, for transporting well injection fluid, and otherwise adapted for use as a carbon dioxide injection riser, applications which readily fall within the scope of subsea fluid transfer applications identified by Rytter for use of the unbonded flexible pipe disclosed therein.
Claim 24 (as understood) is rejected under 35 U.S.C. 103 as being unpatentable over Rytter in view of Droues and Demanze ‘467 as applied to claim 18 above, and further in view of De Souza Pires (US 2021/0048123 A1).
Regarding claim 24, Rytter does not explicitly disclose the additional limitation wherein said at least one elongate element of the anti-bird cage layer comprises said strip of steel or titanium embedded in an embedding material.
De Souza Pires teaches (fig 1) an unbonded flexible pipe (100) comprising a pressure sheath (102), pressure armor layers (103), tensile armor layers (105, 106), and an outer sheath (108).
De Souza Pires further teaches (various embodiments in figs 3-12; paras. 54-58) that a reinforcing element / tape (150) for such an unbonded flexible pipe may comprise a “plurality of filaments” (180) embedded in a matrix material.
De Souza Pires teaches that the “plurality of filaments” are “selected from filament strips/strands and/or fibre filaments and/or rovings and/or braids and/or belts” (para. 54). In particular, De Souza Pires suggests that “the plurality of filaments may include at least one of aramid fibres, glass fibres, basalt fibres, polymer fibres (such as tensilized polyester or polypropylene), metallic or carbon filaments or filament strands. Or, the plurality of filaments may include metallic strips, for example stainless steel” (para. 55).
De Souza Pires provides further details of such a metallic strip and proposes that “In other examples, the plurality of filaments may include a combination of the different filaments listed above.” (para. 56).
Regarding the matrix (embedding) material, De Souza Pires explains that such materials may be thermoplastic polymers, including PVC and PVDF (para. 58).
De Souza Pires teaches that “some reinforcement fibre materials may require protection from the surrounding environment, for instance glass fibres can suffer damage in contact with water and therefore reduced strength over time. Aptly the use of a matrix material can ensure that the fibres remain in position in the reinforcement layer 150”.
Finally, De Souza Pires teaches that such tapes may be designed to include different filaments, configurations of filaments, filament densities, and matrix materials, to balance cost and performance for a particular application, or otherwise to provide desired properties tailored to the application (e.g., resilience vs stiffness, etc.)(paras. 65-66).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the subsea installation of Rytter such that said at least one elongate element of the anti-bird cage layer comprises a strip of steel or titanium (e.g., stainless steel) embedded in an embedding material (e.g., PVDF or PVC), in view of the teachings of De Souza Pires, as the use of a known technique (i.e., providing stainless steel strips as embedded reinforcing filaments in a composite tape element of an unbonded flexible pipe, as in De Souza Pires) to improve a similar device (i.e., unbonded flexible pipe of Rytter, having a fiber-reinforced polymer tape as the at least one elongate element of the anti-bird cage layer) in the same way (e.g., providing improved impact toughness and relative to more brittle mineral fibers); or otherwise as a combination of known prior art elements (i.e., utilizing both inorganic mineral fibers such as basalt, as proposed by Demanze ‘467, and stainless steel strips, as proposed by De Souza Pires) according to known methods (i.e., De Souza Pires suggests that suitable filaments may also include basalt, glass, polymer, metallic or carbon filaments, and teaches that a composite tape may include a combination of different filaments) to obtain predictable results (e.g., providing a composite tape exhibiting properties between those of an inorganic / mineral fiber-reinforced tape and those of a metallic / stainless steel-strip reinforced tape, etc.).
Claim 29 (as understood) is alternatively rejected under 35 U.S.C. 103 as being unpatentable over Rytter in view of Droues and Demanze ‘467 as applied to claim 1 above, and further in view of Demanze (WO 2015/082865 A1; hereafter Demanze ‘865).
Regarding claim 29, as set forth previously in this action, Rytter discloses the additional limitations wherein the unbonded flexible pipe further comprises a stabilization layer (12) located outside the tensile armor layers and wherein the anti-bird cage layer (13) is located onto and in contact with said stabilization layer (fig. 1), and wherein the stabilization layer is made from wound polymeric strips (see para. 75, lines 21-24).
Regarding the limitation wherein the wound polymeric strips are helically wound polymeric strips, as also stated previously, a person having ordinary skill in the art before the effective filing date would have understood that the disclosure of “wound polymeric strips” in this context would reasonably have meant helically wound strips, or otherwise reasonably encompassed embodiments comprising helically wound strips, especially considering that each of the other wound layers disclosed by Rytter (e.g., 2, 5, 6, 9, 10, 13) are helically wound at an angle (i.e., Rytter does not explicitly disclose any circumferentially / ring wound elements).
However, to promote compact prosecution on this issue, the following additional teaching in view of Demanze ‘865 is provided.
Demanze ‘865 teaches (fig. 1) an unbonded flexible pipe comprising a pressure sheath (16), pressure armor (18), tensile armor (22, 25), a stabilization layer (28, including first strip 26) located outside the tensile armors, and an anti-bird cage layer (30) located onto and in contact with said stabilization layer, and wherein the stabilization layer (28) is made from helically wound polymeric strips (see pg. 4, 34-43 of the provided English translation: “a first strip 26 of a polymer material is wrapped in a short pitch around the sheet of outermost armor wires 24 in order to apply it against the cylindrical bearing surface 25….. The first strip 26 made in one of these materials is wound in a helix with short pitch by means of a tape, against
the sheet of armors on 24 so as to overlap the edges of the turns”).
If not already seen as such, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to form the stabilization layer formed from helically wound polymeric strips, in view of the teachings of Demanze ‘865, with a reasonable expectation of success, since Rytter already discloses that such a stabilization layer may be wound from polymeric strips but does not explicitly specify the manner of winding, while Demanze ‘865 teaches that a corresponding wound stabilization layer may be suitably formed by helical winding of the strips.
Claim 31 (as understood) is rejected under 35 U.S.C. 103 as being unpatentable over Rytter in view of Droues and Demanze ‘467 (or Rytter in view of Droues, Demanze ‘467 and Demanze ‘865) as applied to claim 29 above, and further in view of Bai et al. (CN 104089111 A; hereafter Bai).
Regarding claim 31, Rytter discloses that the at least one elongate element of the anti-bird cage layer may be wound with an angle larger than 70°, e.g., larger than 80°; or otherwise between 75° and 90° (para. 32), explaining that “the effect of a higher angle is a more effective reinforcement against radial expansion of the axial armouring layer(s)”.
Rytter does not explicitly disclose the additional limitation wherein the helically wound polymeric strips are wound with a longer pitch (i.e., a smaller angle) than the pitch of the at least one elongate element of the anti-bird cage layer, the helically wound polymeric strips are wound with an angle to the center axis of the unbonded flexible pipe, which is at least 10° less than the winding angle of the elongate element(s) of the anti-bird cage layer.
Bai teaches (fig. 1) an unbonded flexible pipe comprising a pressure sheath (2), a pressure armor (3), a tensile armor (5), an outer sheath (6), and a plurality of intermediate stabilization / anti-wear layers (7), each arranged between respective layers of the pipe.
Bai teaches that these stabilization / anti-wear layers are “made of nylon fibre…wound at an angle of 45 degrees” (e.g., see para. 18, lines 5-6 of the provided English translation).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the subsea installation of Rytter such that the helically wound polymeric strips forming the intermediate stabilization layer were wound at an angle of 45°, in view of the teachings of Bai, as the use of a known technique (i.e., winding an intermediate stabilization / anti-wear layer of an unbonded flexible pipe to have a 45° angle, as in Bai) to improve a similar device (i.e., the unbonded flexible pipe of Rytter, having a polymeric stabilization layer wound at an unspecified angle) in the same way (e.g., providing a stabilization / anti-wear layer wound at an angle known to be suitable in a similar unbonded flexible pipe, in view of Bai).
As Rytter suggests that the elongate element of the anti-bird cage layer should have an angle greater than 70°, e.g., between 85° and 90°, the subsea installation of Rytter, as modified above to have the helically wound polymeric strips of the stabilization layer wound at an angle of 45° reads on the additional limitations wherein the helically wound polymeric strips are wound with a longer pitch (i.e., a smaller angle) than the pitch of the at least one elongate element of the anti-bird cage layer (i.e., 45° vs 70°+), the helically wound polymeric strips are wound with an angle to the center axis of the unbonded flexible pipe, which is at least 10° less than the winding angle of the elongate element(s) of the anti-bird cage layer (45° being 25° less than 70° and 40° less than 85°, for example).
Claim 46 is alternatively rejected under 35 U.S.C. 103 as being unpatentable over Andersen et al. (WO 2018/006919 A1; hereafter Andersen) in view of Droues.
Examination Note: Fig. 2 of Andersen appears substantially identical to Fig. 1 of the instant application except for the specific reference numbers.
Regarding claim 46, Andersen discloses (fig. 2) a subsea installation comprising an unbonded flexible pipe (10) for subsea transportation of a fluid (e.g., see pg. 1, lines 4-5), the unbonded flexible pipe comprises from inside out, a pressure sheath (3) defining a bore for transportation of the fluid, a tensile armor (5, 6) and an outer sheath (7), wherein the tensile armor is located in an annulus (i.e., the annulus formed between pressure sheath 3 and outer sheath 7) and the tensile armor comprises at least two cross wound layers of elongate armor elements (i.e., layers 5 & 6), which are wound with a long pitch (i.e., a small angle, “approximately 55° in respect of the axis” as in pg. 13, lines 23-27; or otherwise in the range of 10° to 50° as in pg. 7, lines 22-25) and wherein the pipe further comprises an anti-bird cage layer (11) comprising at least one elongate element wound with a short pitch (i.e., a large angle, “approximately 82° in respect of the axis” as in pg. 13, line 28 – pg. 14, line 2; or otherwise in the range of 65° to 88.9°, or 70° to 85° as in pg. 7, lines 25-29) onto at least one of the tensile armor layers (as shown), and wherein said at least one elongate element comprises at least one of a strip or a tape (i.e., an “elongate metallic strip”; e.g., see abstract, pg. 6, lines 6-11, etc.), wherein the strip comprises a steel strip or a titanium strip (pg. 9, lines 8-10: “the elongate metallic strip forming the retaining layer is made of steel, titanium, or another metal or alloy, such as e.g. stainless steel, or duplex steel.”) and/or wherein the tape comprises twisted or untwisted continuous fibers embedded in an embedding material, wherein the continuous fibers are arranged to have their length orientated parallel with a length L of the elongate element.
Andersen also discloses a pressure armor (4) between the pressure sheath and the tensile armor.
Regarding the limitation wherein the subsea installation / unbonded flexible pipe is “for subsea transportation of a H2S and/or CO2 containing fluid”, as set forth in MPEP § 2115, a claim is only limited by positively recited elements. Thus, the inclusion of the material or article worked upon by a structure being claimed does not impart patentability to the claims.
Additionally, as set forth in MPEP § 2114(II), apparatus claims cover what a device is, not what a device does. A claim containing a recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus if the prior art apparatus teaches all the structural limitations of the claim.
In the instant case, Andersen discloses that the unbonded flexible pipeline is intended for use with hydrocarbons such as oil and gas, and it is well-known that oil and gas may naturally include some amount of H2S and CO2 (e.g., when obtained from “sour” formations). While Andersen does not explicitly disclose that the unbonded flexible pipe is for transporting an “H2S and/or CO2 containing fluid”, the unbonded flexible pipe is understood to be capable of transporting hydrocarbon fluids such as oil and gas which may contain at least some (naturally occurring) concentration of H2S and CO2, in at least some capacity (i.e., even if the pipe may have a shortened service life under such instances, etc.).
To promote compact prosecution on this issue, an additional teaching in view of Droues is otherwise provided below.
Regarding the limitation wherein the tensile armor is stainless steel, Andersen discloses that tensile armor may be made of carbon steel (pg. 13, lines 23-25), but does not explicitly disclose the tensile armor being made of stainless steel.
However, this feature is otherwise taught by Droues, as also set forth below.
Droues teaches (fig. 1) an unbonded flexible pipe (22) comprising a pressure armor (14) and a tensile armor (16, 18) located in an annulus between an inner pressure sheath (12) and an outer sheath (20).
Droues explains that the tensile armor layers may be formed from corrosion resistant materials such as hammer-hardened austenitic-ferritic stainless steel (e.g., see abstract) to enable the unbonded flexible pipe to be used as a subsea pipe for transporting hydrocarbons having a high content of corrosive gasses such as H2S and CO2 (pg. 1, lines 4-10). More specifically, the unbonded flexible pipe of Droues is intended to operate, e.g., with “polyphase hydrocarbons having a high H2S partial pressure, typically 0.5 to 4 bar, and/or a high CO2 partial pressure, typically at least 5 bar” which are “generally very acid, their pH typically being less than 4.5”, with temperatures which may exceed 90°C, while at depths of “2000m and greater” (pg. 2, line 28 – pg. 3, line 2; pg. 17, lines 9-12).
Droues also suggests that the pressure armor (14) may, in certain embodiments, also be formed from stainless steel. In particular, Droues suggests that the pressure armor may be formed by “a duplex stainless steel wire…wound around the internal pressure sheath” (pg. 10, lines 13-16), and otherwise explains that “according to another embodiment, it is also envisaged producing the pressure vault 14 with wires made of stainless steel or conventional duplex steel that have undergone little or no work-hardening” (pg. 21, lines 31-34). See also, published claim 10 (“…a duplex stainless steel wire is provided for forming said pressure vault (14)”).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the subsea installation unbonded flexible pipe of Andersen such that the tensile armor and the pressure armor are each made of stainless steel (e.g., the tensile armor being formed from a hammer-hardened austenitic-ferritic stainless steel; the pressure armor being formed from a duplex stainless steel which has undergone little or no work-hardening), in view of the teachings of Droues, to enable the unbonded flexible pipe to be used for hydrocarbon bearing formations having a high content of H2S and/or CO2 (i.e., for transportation of a H2S or CO2 containing fluid), as otherwise suggested by Droues, especially considering that it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416.
Regarding the remaining limitation wherein the annulus is free of carbon steel, the pipe of the subsea installation of Andersen, as modified in view of Droues above, is seen as reading on this limitation, as explained below.
In the original configuration of Andersen, the annulus (defined between the pressure sheath 3 and the outer sheath 7) comprises the pressure armor (4), the tensile armor (5 & 6), and the anti-bird cage layer (11).
While one example embodiment of Andersen utilizes carbon steel for the anti-bird cage layer (11), as previously noted, Andersen also discloses other possible materials for the elongate element of the anti-bird cage layers, including titanium, and duplex or stainless steel (pg. 9, lines 8-10: “the elongate metallic strip forming the retaining layer is made of steel, titanium, or another metal or alloy, such as e.g. stainless steel, or duplex steel.”).
Thus, when the pressure and tensile armors are formed from stainless steel (i.e., in view of Droues) and the anti-bird cage layer is formed without carbon steel (e.g., from titanium or a non-carbon steel such as stainless or duplex steel, as disclosed by Andersen), the resulting combination reads on the limitation wherein the annulus is free of carbon steel.
As a result, all of the limitations of claim 46 are met or are otherwise rendered obvious.
Claim 47 (as understood) is rejected under 35 U.S.C. 103 as being unpatentable over Andersen in view of Droues as applied to claim 46 above, and further in view of Griffiths et al. (US 4,773,151; hereafter Griffiths).
Regarding claim 47, the subsea installation of Andersen (as modified above) reads on the limitation wherein said at least one elongate element comprises a strip (i.e. the “elongate metallic strip”), however, Andersen does not explicitly disclose the additional limitation wherein the strip is “embedded in” an organic and/or an inorganic coating selected from the group consisting of an organic coating, a carbon coating and an aluminum coating (see corresponding grounds of rejection under 35 U.S.C. 112 regarding the term “embedded in”).
Griffiths is directed to (figs. 1 & 2) a flexible pipe / hose (10) for transportation of an H2S and/or CO2 containing fluid (see abstract: “suitable for the transportations of biphasic fluids such as crude oil containing hydrogen sulphide”; see col. 2, lines 56-59: test conditions included circulation of CO2 and H2S through a brine solution) and teaches that steel elongate elements (i.e., wire layers 11, 12, comprising cords 13 & 14; each having a steel core 15) of the pipe may be provided with an aluminum coating (16) [see col. 2, lines 18-41].
Griffiths explains that H2S (hydrogen sulfide) is known to penetrate through polymeric materials and into the walls of flexible pipes (hoses), where it may corrode, e.g., high tensile steels (col. 1, lines 11-19). To combat such corrosion, Griffiths proposes coating the steel reinforcement elements with aluminum (e.g., col. 1, lines 45-52; abstract), and provides test data (bottom of column 2 – top of column 3) showing a significant improvement in time-to-failure of aluminum coated steel wires relative to brass-plated and galvanized steel wires in a CO2 and H2S containing environment.
Examination Note: as shown in fig. 2 of Griffiths, the steel elements are completely coated in the aluminum coating and, as understood, would be considered “embedded in” the coating at least to the same extent as applicant’s disclosed strip may be considered “embedded in” such a coating.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the subsea installation of Andersen such that the strip is embedded in an organic and/or an inorganic coating selected from the group consisting of an organic coating, a carbon coating and an aluminum coating (e.g., an aluminum coating, as taught by Griffiths), in view of the teachings of Griffiths, in order to protect the strips (which, as noted for claim 46, may be steel such a stainless or duplex steel) from hydrogen embrittlement and/or corrosion when the unbonded flexible pipe is used to transport an H2S and/or CO2 containing fluid (e.g., as otherwise suggested by Droues).
The above modification would have been otherwise obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention as the use of a known technique (i.e., providing an aluminum coating on steel elongate reinforcement elements of a flexible pipe / hose) to improve a similar device (i.e., the unbonded flexible pipe of the subsea installation of Andersen, as otherwise modified above) in the same way (e.g., to mitigate against embrittlement and/or corrosion in an environment containing H2S and/or CO2, extending the useful life of the flexible pipe).
Examination Note: to promote compact prosecution, it is noted that providing a metal strip of an unbonded flexible pipe with an organic and/or inorganic coating, in general (i.e., for corrosion / hydrogen sulfide resistance) is otherwise known in the art. E.g., see US 8,636,037 to Ishii et al., which teaches both plating the surface of such a metallic strip (i.e., an inorganic coating) and further providing a resin (i.e., organic) coating. Similarly, embedding a metal strip in an organic [polymeric] layer is known in the art. See, e.g., US 2021/0048123 A1 to De Souza Pires, cited in the rejection of claim 24 above.
Comments on Additional Relevant Prior Art
The prior art made of record in the attached PTO-892 and not relied upon is considered pertinent to applicant's disclosure. To promote compact prosecution, the attention is drawn to the following references cited therein, which are seen as being particularly relevant:
US 2020/0031071 A1 to Al-Zubaidy et al. teaches the use of thermoplastic composite tapes in making unbonded flexible pipes. Of note, Al-Zubaidy discloses (para. 50) that the unbonded flexible pipe may comprise a tape layer (104) to “help contain underlying layers” and which “may be a polymer or composite or a combination of materials”. For example, “the tape layer 104 may be formed of the thermoplastic composite” described therein.
US 2009/0218093 A1 to Gudme disclose a duplex stainless steel which may be used for any or all armoring layers of an unbonded flexible pipe. Gudme discloses that this duplex steel is intended to be sufficiently resistant to corrosion even when used in aggressively corrosive environments (such as when transporting H2S) and in deep water applications. Gudme provides comparative test data of this stainless steel in simulated CO2 & H2S environments having a pH value down to at least 4.0.
US 2010/0101675 A1 to Do et al. discloses a subsea flexible pipe comprising an anti-bird cage / holding layer (12) which “may consist of several strips, tapes, holding bands or unitary elements wound in a short pitch around the outer armor lap 14” (para. 34), wherein such a “unitary element” may comprise “a fiber holding band covered with a polymer reinforcing layer” (para. 35). In one example, the holding layer comprises longitudinal fiber bundles (which may be aramid or polyethylene)(para. 36) embedded in a polymer reinforcing layer (35)(para. 38) which may be selected from a variety of thermoplastic polymers, including PVDF (para. 39).
Response to Arguments
Applicant's arguments filed 09 October 2025 have been fully considered.
First, in responding to a rejection under 35 U.S.C. 112(b), applicant suggests that “In the instant application, the term “strip” refers to a metallic strip and the term “tape” refers to an elongate element having embedded fibers and/or embedded strips”. While the specification does use the term “strip” in at least one instance to refer to a metallic strip (e.g., para. 129) and does use the term “tape” in at least one instance to refer to an elongate element having embedded fibers / strips, it is not clear that the original specification intended these terms to be distinctly limited to these narrower meanings throughout. In fact, the specification includes numerous counter-examples: paragraphs 74: “the stabilization layer is provided from helically wound polymeric strips. The helically wound polymeric strips may advantageously be of polyethylene, PVDF, PEEK, PVC or any combination thereof optionally comprising embedded fibers” (i.e., the polymeric element is referred to as a “strip” rather than a tape, and embedded fibers are optional; see also para. 113); Paragraph 103: “the anti-bird cage elongate element is [shaped] as flat strips” (i.e., the elongate element, comprising the embedded fibers / metallic strips, is referred to as a “strip” rather than a tape); Paragraph 105: “a carcass 12 manufactured by winding and folding a metallic tape 12a” (i.e., the tape is metallic, rather than an element having embedded fibers/strips); paragraph 109: “wound PVDF tape” (i.e., the tape is a polymeric tape; no embedded fibers / strips are mentioned).
Applicant argues that “Rytter provides a clear teaching away” from references disclosing the use of embedded fibers that “would render the prior art reference… unsatisfactory for its intended purpose and change the principle of operation of the prior art reference”. This argument is not found to be persuasive.
Rytter clearly discloses that the use of fiber-reinforced tapes is a known solution.
Indeed, applicant’s own WO 2018/006919 A1 (cited in this action as Andersen et al.) appears to admit that Rytter discloses such composite tapes (see pg. 3, lines 19-35: “…an outer armouring layer is sometimes wound at a large angle around the tensile armouring layer(s). This armouring layer is made of very flat profiles in the form of fibre reinforced polymeric tapes and often referred to as a retaining layer….Tapes of this type are e.g. disclosed in US- 2004/0025953 and in WO 2006/005689.”; the aforementioned WO 2006/005689 corresponds to Rytter (i.e., WO 2006/005689 is the publication of PCT/EP2005/053143 to which Rytter claims priority).
Rytter’s issue with the known prior art solution is not that it is fundamentally unsuitable from a technical perspective, but only that each form of tape is specifically manufactured for a particular application, so manufacturing a wide range of pipes (e.g., from 2” to 16”) would require a large number of tape variants. Rytter further explains that the advantage is one of construction and manufacturing freedom, rather than some unexpected performance improvement in the final end product.
"A known or obvious composition does not become patentable simply because it has been described as somewhat inferior to some other product for the same use." In re Gurley, 27 F.3d 551, 554, 31 USPQ2d 1130, 1132 (Fed. Cir. 1994).
As set forth in MPEP § 2143.01(V), ‘[a] given course of action often has simultaneous advantages and disadvantages, and this does not necessarily obviate motivation to combine’" Allied Erecting v. Genesis Attachments, 825 F.3d 1373, 1381, 119 USPQ2d 1132, 1138 (Fed. Cir. 2016)(quoting Medichem, S.A. v. Rolabo, S.L., 437 F.3d 1157, 1165, 77 USPQ2d 1865, 1870 (Fed. Cir. 2006) (citation omitted)).
While Rytter discloses a preference for using unembedded fibers rather than composite tapes, for the expected advantage of providing more flexible manufacturing of multiple pipe sizes, such a solution is not without disadvantages.
As would be known to those skilled in the art, and as otherwise taught by at least Demanze ‘467, certain fibers such as organic fibers, are susceptible to hydrolysis when exposed. Thus, it is known to embed the fibers in a matrix to protect the fibers from corrosion and/or mechanical wear / damage, extending the lifetime of the fibers. See also a similar teaching by De Souza Pires that “some reinforcement fibre materials may require protection from the surrounding environment, for instance glass fibres can suffer damage in contact with water and therefore reduced strength over time. Aptly the use of a matrix material can ensure that the fibres remain in position in the reinforcement layer”.
A person having ordinary skill in the art before the effective filing date of the claimed invention would have been capable of weighing the expected benefits and disadvantages of both solutions (i.e., the exposed fiber method of Rytter, which provides manufacturing flexibility at the cost of fiber protection, vs. the known prior art tape method as taught by Rytter and Demanze ‘467, etc., which provides protection and extended lifetime to the fibers via embedding in a matrix, but requires tapes tailored to the specific application), and determining which solution is better for a particular application. By way of example, if performance and service life in a corrosive environment were most important, then the performance / longevity benefits of using a reinforced composite tape could reasonably justify the additional cost of manufacturing different tapes for different sizes of a pipe.
Regarding applicant’s argument that the teachings of the prior art tapes are “incompatible” with those of Rytter and would render Rytter “unsatisfactory for its intended purpose and change its principles of operation”, these arguments are not found to be persuasive.
As a preliminary note, the patent number (US 6,165,856) cited in the published application of Rytter does indeed appear to be a typographical error. In the subsequent patent (US 7,987,875) issued to Rytter, the number was corrected to US 6,165,586 (Noveau et al.; “Flat Strip” for reinforcing ducts). US 6,165,586 is also cited in US 2014/0124078 to Glejbol et al. (para. 8).
Returning to the substance of the argument, as previously stated, Rytter does not “teach away” from the use of embedded fiber tapes, but merely describes them as inferior to their proposed solution due to manufacturing complexity when making different pipe sizes. While modifying the pipe of Rytter to use such tapes would forgo the expected manufacturing benefits, such a modification would provide other benefits (i.e., performance and longevity). That is, they are merely different solutions for constructing the same functional layer, and Rytter does not explicitly teach that the use of the prior art composite tapes would have resulted in an inoperable unbonded flexible pipe, but merely one more complex to produce in different sizes.
In context, Rytter’s use of fibrous cords is understood to be a substitution of such cords in place of the prior art composite tapes. That is, the difference is the construction of the anti-bird cage layer from fibrous cords rather than a tapes. However, they each generally function in the same manner: they are each wound around the outside of the axial armoring layer(s) to prohibit large radial deformations. In other words, an unbonded flexible pipe would be understood to rely upon substantially the same principles of operation whether the anti-bird cage layer is formed from a fibrous layer or a composite tape. Other than the construction of the elongate element of the anti-bird cage layer itself, applicant has not articulated how such a modification would operate differently, or in what manner the proposed combination would require substantial reconstruction or redesign.
As set forth in MPEP § 2123(I), "The use of patents as references is not limited to what the patentees describe as their own inventions or to the problems with which they are concerned. They are part of the literature of the art, relevant for all they contain." In re Heck, 699 F.2d 1331, 1332-33, 216 USPQ 1038, 1039 (Fed. Cir. 1983) (quoting In re Lemelson, 397 F.2d 1006, 1009, 158 USPQ 275, 277 (CCPA 1968)). A reference may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art, including nonpreferred embodiments. Merck & Co. v. Biocraft Labs., Inc. 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir. 1989), cert. denied, 493 U.S. 975 (1989).
Thus, while Rytter might consider their invention to be the use of a fibrous cord rather than a composite tape, the use of the reference as prior art is not limited thereto. The disclosure of Rytter includes substantial details of an unbonded flexible pipe, including details and arrangements of layers other than the anti-bird cage layer, and may also be relied upon for the disclosure of such elements, including the general arrangement of the unbonded flexible pipe. While Rytter prefers the use of a fibrous cord for the anti-bird cage layer, the background section clearly discloses that the use of embedded fiber tapes is also known for such purpose, wherein such a disclosure is reasonably seen as disclosure of a non-preferred embodiment. As above, a reference may be relied upon for all that it would have reasonably suggested, including nonpreferred embodiments. See also MPEP § 2123(II).
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning (i.e., in connection with the annulus being free of carbon steel), it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
As noted in the grounds of rejection, the pipe of the subsea installation of Rytter, as modified in view of Demanze ‘467 and Droues above, is seen as reading on this limitation.
In the original configuration of Rytter, the annulus (defined between the pressure sheath 4 and the outer sheath 14) comprises the pressure armor (5 & 6), an optional polymeric intermediate anti-friction layer (11), the tensile armor (9 & 10), another optional polymeric intermediate layer (12), and the anti-bird cage layer (13).
As set forth, forming the pressure and tensile armors from stainless steel would have been obvious in view of Droues (e.g., to enable the unbonded flexible pipe to be used for hydrocarbon bearing formations having a high content of H2S and/or CO2).
Similarly, as set forth, forming the anti-bird cage layer as a polymer composite tape comprising, e.g., basalt or carbon fibers embedded in PEEK, would have been obvious at least in view of Demanze ‘467 (e.g., to provide fibers which are less vulnerable to corrosion).
Thus, the resulting annulus (defined between the pressure sheath 4 and the outer sheath 14) would comprise: stainless steel pressure armor, an optional polymeric intermediate anti-friction layer, stainless steel tensile armor, another optional polymeric intermediate layer, and the composite tape anti-bird cage layer. As can be seen, none of the components in the annulus would comprise carbon steel, whereby the resulting combination would read on the limitation wherein the annulus is free of carbon steel, without further modification.
Applicant argues that the examiner has not articulated why a person of ordinary skill in the art would have been prompted to modify Rytter to have pressure and tensile armors formed without carbon steel and to have the anti-bird cage layer formed without carbon steel. This argument is not found to be persuasive. As noted above, the grounds of rejection include articulated reasoning why each of these modifications would have been obvious to a person having ordinary skill in the art. There is no requirement that both modifications must be suggested by a single reference. The test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981).
Regarding applicant’s remarks that Droues does not include an anti-bird cage layer, and that Demanze ‘467 does not teach omitting carbon steel from the pressure and tensile armors, it is noted that Droues and Demanze ‘467 were not relied upon to teach those respective features, which were either already present in the primary reference(s) or were taught by the other secondary reference. One cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
Applicant argues that, by replacing the carbon steel with a corrosion resistant material, the pH value in the annulus would drop, with the resulting acidic environment inducing hydrolysis of the aramid tapes, which might eventually lead to failure of the aramid tapes.
This argument is not found to be persuasive for several reasons.
First, applicant’s own specification appears to admit that Droues (GB 2481175) teaches the use of stainless steel for at least the tensile armor (see published para. 14) and, later, appears to admit that the use of stainless steels or composites for tensile and pressure armor layers to protect them from corrosion is otherwise known (see published paras. 23 & 24).
For completeness, however, it is noted that Droues does reasonably teach the use of stainless steel for both the pressure armor and tensile armor layers. In particular, Droues teaches that components located in the annulus of an unbonded flexible pipe used to transport acidic / corrosive fluids (e.g., H2S) may be exposed to such fluids; that certain corrosion resistant stainless steels may be suitably used in such applications; and that carbons steels, when used in such environments, exhibit tradeoffs between corrosion resistance and mechanical properties: that is, stronger carbon steels are relatively more susceptible to corrosion. Droues then proposes several possible solutions:
In a first embodiment, they propose the use of stainless steel tensile armor in combination with carbon steel pressure armor, wherein the pressure armor is permitted to corrode at the surface, to “consume” the H2S and protect the stainless steel tensile armor, preventing excessing pH in the annulus and enabling the use of “bottom-of-the-range” or “middle-of-the-range” duplex steels. Of note, the use of “at least one carbon steel wire” for the pressure armor is disclosed only as “preferable” rather than required.
In a second embodiment, when no pressure armor is provided (and thus, as understood, no mechanism is provided to consume the H2S / mitigate against low pH), they suggest that the tensile armor should use “middle-of-the-range” or “top-of-the-range” duplex stainless steels.
In a third embodiment, they propose that both the pressure armor and the tensile armor could be formed from stainless steels (“According to another embodiment of the pressure vault, a duplex stainless steel wire is provided”; “…according to yet another embodiment, it is also envisaged producing the pressure vault 14 with wires made of stainless steel or conventional duplex steel…”). As with the second embodiment, this would have been understood by those skilled in the art to include embodiments wherein no carbon steel is provided, and thus no mechanism is provided to consume the H2S / mitigate against low pH.
Regarding applicant’s suggestion that “In Droues, it is clearly taught that carbon steel should be located in the annulus to consume H2S”, as noted above, and detailed at length in previous responses on 22 January 2025 and 16 July 2025, this argument is not found to be persuasive. While the section of Droues cited by the applicant does suggest that the pressure armor may be formed by a carbon steel wire which may be consumed by diffusing H2S to form iron sulfides, thus avoiding corrosion of the stainless steel (tensile) armor plies, this is only one preferred embodiment among several embodiments disclosed by Droues. As noted, in at least one alternative embodiment, Droues explicitly teaches the use of a stainless steel (rather than carbon steel) as the pressure armor material (see, e.g., pg. 10, lines 13-16; pg. 21, lines 31-34).
Thus, when read in its entirety, the disclosure of Droues is not reasonably seen as teaching away from the use of stainless steel for the pressure armor (and thus an annulus free of carbon steel).
Returning to the issue of the lower pH value in the annulus caused by removing carbon steel inducing hydrolysis of the aramid tapes, which might eventually lead to failure of the aramid tapes, it is noted that environmental hydrolysis of organic (e.g., aramid) tapes is already an issue known from the prior art, as are applicant’s proposed solutions.
By way of example, Demanze ‘467 teaches that anti-bird cage layers (“holding strips”) are known which use organic fibers such as aramid and, to extend the lifetime of such fibers, it is known to coat such fiber strips in polymer materials; however, such coating alone may not sufficiently protect fibers against degradation in all operating conditions, especially “very deep marine conditions” (para. 7). Demanze ‘467 then explains that inorganic mineral fibers (e.g., glass, basalt, ceramic, carbon) may be used instead of such aramid (organic) fibers (para. 12), and “possess the advantage of being much more resistant to hydrolysis than organic fibers” (para. 13). Demanze ‘467 further suggests that basalt fibers in particular have good resistance to hydrolysis (para. 14).
Thus, the combined teachings of Rytter, Droues, and Demanze ‘467 render obvious a subsea installation comprising an unbonded flexible pipe as claimed, having stainless steel pressure and tensile armors (i.e., in view of Droues) and an anti-bird cage layer comprising at least one elongate element in the form of, e.g., a tape of basalt fibers embedded in PEEK, with the resulting combination having an annulus free of carbon steel (as previously explained).
As best understood, in general, applicant appears to be arguing that the prior art does not explicitly disclose selecting the at least one elongate element specifically so as to be resistant to the increased acidity which results from replacing carbon steel armoring wires with corrosion-resistant / stainless steel wires, however, there is no requirement that the reasons for modification must be the same as applicant’s reasons for making the same modifications.
The fact that the inventor has recognized another advantage (i.e., protecting the anti-birdcage layer from hydrolysis, thus extending service life, when the annulus experiences low pH due to omission of carbon steel armoring) which would flow naturally from following the suggestion of the prior art (i.e., using stainless steel rather than carbon steel to protect the armoring, as in Droues; using hydrolysis resistant fiber-reinforced tapes for an anti-birdcage layer, as in Demanze ‘467) cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
See also MPEP § 2144(IV): The reason or motivation to modify the reference may often suggest what the inventor has done, but for a different purpose or to solve a different problem. It is not necessary that the prior art suggest the combination to achieve the same advantage or result discovered by applicant. See, e.g., In re Kahn, 441 F.3d 977, 987, 78 USPQ2d 1329, 1336 (Fed. Cir. 2006) (motivation question arises in the context of the general problem confronting the inventor rather than the specific problem solved by the invention); Cross Med. Prods., Inc. v. Medtronic Sofamor Danek, Inc., 424 F.3d 1293, 1323, 76 USPQ2d 1662, 1685 (Fed. Cir. 2005) ("One of ordinary skill in the art need not see the identical problem addressed in a prior art reference to be motivated to apply its teachings.").
Finally, it is noted that at least independent claim 46 was rejected in the previous action on alternative grounds over Andersen et al. (WO 2018/006919 A1; hereafter Andersen) in view of Droues. Andersen explicitly teaches an elongate element for an anti-bird cage layer taking the form of a strip of steel or titanium (pg. 9, lines 8-11: “The elongate metallic strip forming the retaining layer is made of steel, titanium, or another metal or alloy, such as e.g., stainless steel, or duplex steel…”). Applicant’s remarks filed 09 October 2025 do not appear to specifically address this alternative rejection, which is maintained in this action.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/Richard K. Durden/Examiner, Art Unit 3753
/KENNETH RINEHART/Supervisory Patent Examiner, Art Unit 3753