DETAILED CORRESPONDENCE
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claims 20, 22, 23, 27, 28, 30, 31 & 33-36 have been examined in this application. This communication is a Non-Final Rejection in response to the Request for Continued Examination (RCE) filed on June 9, 2026. Claims 1-19, 21, 25, 29 & 32 stand canceled. Claims 24 & 26 stand withdrawn (Claim 26 is presented as dependent on canceled Claim 25. For purposes of examination, the Office considers Claim 26 as dependent on Claim 24).
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicants’ submission filed on June 9, 2026 has been entered.
Claim Rejections - 35 USC § 112
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 33 & 35 are 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 pre-AIA the inventor(s), at the time the application was filed, had possession of the claimed invention. Claim 33 recites “wherein the plug fills the full diameter of the well” and Claim 35 recites “wherein filling the length of the well with the alloy composition in the molten state comprises filling the full diameter of the well with the alloy composition in the molten state”. The instant specification appears to discuss the plug and related method steps of filling with respect to a length of the well, and does not appear to discuss the same with respect to the diameter or the full diameter of the well. While Applicants’ remarks cite portions of pages 8, 14 & 21 of the instant specification for support, it is noted that these portions do not appear discuss filling the full diameter of the well as respectively claimed. In abandonment operations, plugging does not necessarily require filling of the full diameter, and may include filling leaks, limited/desired regions etc. (as also discussed on at least page 1 of the instant specification). As such, the plug comprising the instantly claimed alloy composition filling the “full diameter of the well” as respectively claimed is not sufficiently described in the specification as required above. Appropriate correction and/or clarification is required.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 20, 22, 23, 27, 28, 30, 31, 33 & 35 are rejected under 35 U.S.C. 103 as being unpatentable over Billingham et al. (US 2018/0298720).
With respect to Claim 20, Billingham discloses a plug for sealing a well comprising an alloy composition of bismuth and silver, the plug filling a length of the well (Billingham: Sections [0007], [0008], [0031], [0033] & [0034]; Figures 2 & 3); wherein, as a non-limiting example, Billingham teaches filling areas such as “56”, which is considered to disclose sealing a well and filling a length of the well as broadly claimed; and wherein Billingham further teaches examples of such alloys comprising amounts of bismuth and silver in ranges that overlap with the preferred range (3%-9% by weight silver) of the instant invention as presented in the instant specification (page 9); and also teaches providing the alloy/fill material so as to have sufficient fluid viscosity in the molten state for wellbore applications.
As such, although the reference fails to explicitly limit the weight ranges of bismuth and silver to the ranges as respectively claimed, before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to provide/prepare the alloy as desired with suitable amounts of bismuth and silver to tailor properties such as fluid viscosity insofar as because it has been held wherein generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) (Claimed process which was performed at a temperature between 40°C and 80°C and an acid concentration between 25% and 70% was held to be prima facie obvious over a reference process which differed from the claims only in that the reference process was performed at a temperature of 100°C and an acid concentration of 10%.). See also Peterson, 315 F.3d at 1330, 65 USPQ2d at 1382 wherein it was held "The normal desire of scientists or artisans to improve upon what is already generally known provides the motivation to determine where in a disclosed set of percentage ranges is the optimum combination of percentages." and In re Hoeschele, 406 F.2d 1403, 160 USPQ 809 (CCPA 1969) wherein claimed elastomeric polyurethanes which fell within the broad scope of the references were held to be unpatentable thereover because, among other reasons, there was no evidence of the criticality of the claimed ranges of molecular weight or molar proportions). For more recent cases applying this principle, see Merck & Co. Inc. v. Biocraft Lab. Inc., 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir.), cert. denied, 493 U.S. 975 (1989); In re Kulling, 897 F.2d 1147, 14 USPQ2d 1056 (Fed. Cir. 1990); and In re Geisler, 116 F.3d 1465, 43 USPQ2d 1362 (Fed. Cir. 1997); Smith v. Nichols, 88 U.S. 112, 118-19 (1874) (a change in form, proportions, or degree "will not sustain a patent"); In re Williams, 36 F.2d 436, 438 (CCPA 1929) ("It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions."). See also KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007) (identifying "the need for caution in granting a patent based on the combination of elements found in the prior art."). The instant specification fails to explicitly establish the instantly claimed concentration ranges for each component as critical, particularly in comparison to the instantly described broader preferred range, and it is unclear if any unexpected results are achieved by using only the instantly claimed concentration ranges. Since the alloy of Billingham is suggested as achieving sealing/a plug as broadly and instantly claimed, it does not appear that such would be considered an unexpected result of using the presently claimed concentration ranges, and, as such, the determination of percents of each component as claimed would be achievable through routine experimentation in the art.
It is also noted that, before the effective filing date of the claimed invention, there had been a recognized need in the art for providing alloys comprising bismuth and silver, and a finite number of identified, predictable solutions including tailoring the alloy for desired properties such as fluid viscosity, as set forth above. As such, before the effective filing date of the claimed invention, based on the teachings of Billingham, one of ordinary skill in the art could have pursued desired weights of the alloy components, i.e., bismuth and silver, with a reasonable expectation of success. The rationale to support a conclusion that the claim would have been obvious is that "a person of ordinary skill has good reason to pursue the known options within his or her technical grasp. If this leads to the anticipated success, it is likely that product [was] not of innovation but of ordinary skill and common sense. In that instance the fact that a combination was obvious to try might show that it was obvious under § 103."KSR, 550 U.S. at 421, 82 USPQ2d at 1397.
With respect to Claim 22, Billingham teaches the plug as provided above with respect to Claim 20, and further discloses “…wherein the well is an oil well” (Billingham: Sections [0007] & [0008]).
With respect to Claim 23, Billingham discloses a method of forming a plug in a well comprising an alloy composition of bismuth and silver, the method comprising: filling a length of the well with the alloy composition in a molten state; and allowing the alloy composition in the molten state to solidify (Billingham: Sections [0007], [0008], [0031], [0033] & [0034]; Figures 2 & 3); wherein, as a non-limiting example, Billingham teaches filling areas such as “56”, which is considered to disclose filling a length of the well as broadly claimed; and wherein Billingham further teaches examples of such alloys comprising amounts of bismuth and silver in ranges that overlap with the preferred range (3%-9% by weight silver) of the instant invention as presented in the instant specification (page 9); and also teaches providing the alloy/fill material so as to have sufficient fluid viscosity in the molten state for wellbore applications.
As such, although the reference fails to explicitly limit the weight ranges of bismuth and silver to the ranges as respectively claimed, before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to provide/prepare the alloy as desired with suitable amounts of bismuth and silver to tailor properties such as fluid viscosity insofar as because it has been held wherein generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) (Claimed process which was performed at a temperature between 40°C and 80°C and an acid concentration between 25% and 70% was held to be prima facie obvious over a reference process which differed from the claims only in that the reference process was performed at a temperature of 100°C and an acid concentration of 10%.). See also Peterson, 315 F.3d at 1330, 65 USPQ2d at 1382 wherein it was held "The normal desire of scientists or artisans to improve upon what is already generally known provides the motivation to determine where in a disclosed set of percentage ranges is the optimum combination of percentages." and In re Hoeschele, 406 F.2d 1403, 160 USPQ 809 (CCPA 1969) wherein claimed elastomeric polyurethanes which fell within the broad scope of the references were held to be unpatentable thereover because, among other reasons, there was no evidence of the criticality of the claimed ranges of molecular weight or molar proportions). For more recent cases applying this principle, see Merck & Co. Inc. v. Biocraft Lab. Inc., 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir.), cert. denied, 493 U.S. 975 (1989); In re Kulling, 897 F.2d 1147, 14 USPQ2d 1056 (Fed. Cir. 1990); and In re Geisler, 116 F.3d 1465, 43 USPQ2d 1362 (Fed. Cir. 1997); Smith v. Nichols, 88 U.S. 112, 118-19 (1874) (a change in form, proportions, or degree "will not sustain a patent"); In re Williams, 36 F.2d 436, 438 (CCPA 1929) ("It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions."). See also KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007) (identifying "the need for caution in granting a patent based on the combination of elements found in the prior art."). The instant specification fails to explicitly establish the instantly claimed concentration ranges for each component as critical, particularly in comparison to the instantly described broader preferred range, and it is unclear if any unexpected results are achieved by using only the instantly claimed concentration ranges. Since the alloy of Billingham is suggested as achieving sealing/a plug as broadly and instantly claimed, it does not appear that such would be considered an unexpected result of using the presently claimed concentration ranges, and, as such, the determination of percents of each component as claimed would be achievable through routine experimentation in the art.
It is also noted that, before the effective filing date of the claimed invention, there had been a recognized need in the art for providing alloys comprising bismuth and silver, and a finite number of identified, predictable solutions including tailoring the alloy for desired properties such as fluid viscosity, as set forth above. As such, before the effective filing date of the claimed invention, based on the teachings of Billingham, one of ordinary skill in the art could have pursued desired weights of the alloy components, i.e., bismuth and silver, with a reasonable expectation of success. The rationale to support a conclusion that the claim would have been obvious is that "a person of ordinary skill has good reason to pursue the known options within his or her technical grasp. If this leads to the anticipated success, it is likely that product [was] not of innovation but of ordinary skill and common sense. In that instance the fact that a combination was obvious to try might show that it was obvious under § 103."KSR, 550 U.S. at 421, 82 USPQ2d at 1397.
With respect to Claims 27, 28, 30 & 31, Billingham teaches the plug and method as provided above with respect to Claims 20 & 23, respectively, and further teaches the respective amounts of bismuth and silver for reasons as set forth above with respect to Claims 20 & 23, respectively.
With respect to Claims 33 & 35, Billingham teaches the plug and method as provided above with respect to Claims 20 & 23, respectively, and further discloses one or more embodiments where filling areas are circumferential, and where areas such as “56” complete a full circle, and one or more embodiments where the composition cools and solidifies within the casing; which is considered to disclose filling both within and outside the casing, i.e., the full diameter of the well as broadly and respectively claimed (Billingham: Sections [0022], [0029] & [0034]). As such, although the reference fails to explicitly disclose filling a full diameter of the well in combination with the features of the above plug and method, respectively, in a single embodiment, as instantly claimed, before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to have modified the above plug and method, respectively, to fill the full diameter of the well, as respectively claimed, with a reasonable expectation of success, in order to seal the well.
Claims 34 & 36 are rejected under 35 U.S.C. 103 as being unpatentable over Billingham et al. (US 2018/0298720), in view of Spencer (US 2003/0132224).
With respect to Claims 34 & 36, Billingham teaches the plug and method as provided above with respect to Claims 20 & 23, respectively; and further teaches one or more embodiments where the plug/composition is employed in sealing cracks/voids in cement, and cools and solidifies within the casing, and may be removed if undesired depending on the implementation (Billingham: Sections [0002]-[0009], [0034] & [0035]). The reference, however, fail to explicitly disclose the plug to “abandon the well” and the method steps as “sealing and abandoning the well”, as respectively claimed.
Spencer teaches methods of repairing and sealing wells therein, wherein bismuth-based alloys provide improved bonding with lower viscosity, in comparison to cement, and are employed to seal faults in cement to improve production efficiencies or to terminate leaks for well abandonment; and also teaches wherein solidified material within the casing may be drilled out, as is known, if the well is intended to continue in production or can be left undrilled in place if the well is to be abandoned (Spencer: Sections [0002], [0006]-[0009] & [0056]-[0066]). As such, before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to have modified Billingham with the aforementioned teachings of Spencer to leave in place the solidified plug within the casing if desired, to seal/abandon the well, as an alternative to removing the same, with a reasonable expectation of success, in order to benefit from the properties of bismuth-based plugs and/or to yield predictable results in well sealing/plugging operations. (Spencer: Sections [0002], [0006]-[0009] & [0056]-[0066]).
Response to Arguments
Applicants' amendments regarding the claim objections are persuasive and, therefore, these objections have been withdrawn.
Applicants' arguments regarding the 35 USC 112 rejections have been fully considered but they are not persuasive. Applicants assert that (1) the specification explicitly describes forming a plug by introducing a molten alloy into the well such that "a length of the well is filled with the molten alloy ... and allowed to solidify." ( [0034]); (2) the specification further discloses that, upon solidification, the alloy "expands upon solidification and exerts a radial force on the sides of the well." ( [0052]); and (3) a person of ordinary skill in the art would understand that this described mechanism of operation requires that the alloy, upon solidification, engages the surrounding well structure; the exertion of a radial force on the sides of the well implies that the alloy is in contact with the well wall across the wellbore cross-section over the filled length; and partial or non-full-diameter fill would not permit uniform radial force generation or reliable sealing, and thus would be inconsistent with the described operation of the invention.
The Examiner respectfully disagrees.
While Applicants’ remarks cite portions of the instant specification for support, it is noted that these portions do not appear discuss filling the full diameter of the well as asserted. It is noted that “a length of the well” as instantly described does not necessarily limit the seal/plug to an entire length of the well or any specific length of plug. Further, in abandonment operations, plugging does not necessarily require filling of the full diameter, and may include filling leaks, limited/desired regions etc. (as also discussed on at least page 1 of the instant specification). Further, “radial pressure” refers to pressure acting in the direction of the radius. Radial pressure does not necessarily equate only to pressures generated uniformly by a full diameter fill. A plug that partially fills a diameter can generate pressure in the direction of the radius. The specification does not appear to describe a “uniform radial force generation”, “across the wellbore cross-section”, as asserted. As such, the plug comprising the instantly claimed alloy composition filling the “full diameter of the well” as respectively claimed is not sufficiently described in the specification as required above; and the rejection under 35 USC 112 is maintained as set forth above.
Applicants’ arguments with respect to the rejection(s) of Claims 20, 22, 23, 27, 28, 30, 31 & 33-36 under 103 as being unpatentable over Billingham et al., alone or in combination with Spencer, have been fully considered but they are not persuasive. As such, for reasons discussed below, the claims remain rejected under 35 USC 103 in view of Billingham et al., alone or in combination with Spencer, as set forth above, with updates to address any amendments.
It is also noted that the Examiner left voice messages for Attorney Nicholas Kuchinski on 9/11/2026 & 9/15/2026 to discuss potential Examiner’s Amendments, related to one or more features presented in the arguments but not recited in the instant claims; however, no reply has been received.
Applicants assert that the claimed range of silver is critical to the invention and is not simply a matter of routine optimization, and the Declaration of Prof. Robert Eden provides comparative data for bismuth-silver alloys evaluating liquidus/solidus temperatures, Ultimate Tensile Strength (UTS), Ultimate Compressive Stress (UCS), and time to rupture at 130°C, that establishes that the claimed silver concentration range yields superior performance that is not predictable from the comparative alloys. The claimed range therefore defines a critical region of operation and is associated with unexpected results, rather than reflecting routine optimization of known alloy compositions.
The Examiner respectfully disagrees.
In response to Applicants’ argument that the references fail to show certain features of Applicants’ invention, it is noted that the features upon which Applicants rely (i.e., physical performance properties of the claimed alloy, including liquidus/solidus temperatures, Ultimate Tensile Strength (UTS), Ultimate Compressive Stress (UCS, and time to rupture at 130°C as detailed in the Declaration) are not recited in the rejected claim(s). It is further noted that the physical performance properties data presented in the Declaration for the inventive compositions do not appear to be presented in the instant disclosure as originally filed. To the extent this information is presented in the instant disclosure as originally filed, it is further noted that although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
The instant claims broadly recite a plug for sealing/formed in a well comprising an alloy composition of bismuth and silver in the claimed ranges. Billingham teaches examples of alloys comprising amounts of bismuth and silver in ranges that overlap with the preferred range (3%-9% by weight silver) of the instant invention as presented in the instant specification (page 9). The instant specification fails to explicitly establish the instantly claimed concentration ranges for each component as critical, particularly in comparison to the instantly described broader preferred range, and it is unclear if any unexpected results are achieved only by using the instantly claimed concentration ranges. Since the alloy of Billingham is suggested as achieving sealing/a plug as broadly and instantly claimed, it does not appear that such would be considered an unexpected result of using the presently claimed concentration ranges, and, as such, the determination of percents of each component as claimed would be achievable through routine experimentation in the art. As such, the claimed weight range is considered obvious to one of ordinary skill in the art for reasons as set forth above.
Applicants assert that Billingham explicitly defines a microannulus as "a circumferential or partially circumferential gap between the casing and cement or between the cement and the wall of the formation." [0022]; thus, even where such a microannulus may extend circumferentially or form a "full circle," as described in [0030], the resulting structure is annular in nature and remains a hollow region surrounding the casing, rather than a continuous body occupying the wellbore cross- section; and accordingly, Billingham does not disclose at least "filling the full diameter of the well" as instantly claimed.
The Examiner respectfully disagrees.
Billingham further discloses one or more embodiments where filling areas are circumferential, and where areas such as “56” complete a full circle, and one or more embodiments where the composition cools and solidifies within the casing; which is considered to disclose filling both within and outside the casing, i.e., the full diameter of the well as broadly and respectively claimed (Billingham: Sections [0022], [0029] & [0034]). As such, although the reference fails to explicitly disclose filling a full diameter of the well in combination with the features of the above plug and method, respectively, in a single embodiment, as instantly claimed, before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to have modified the above plug and method, respectively, to fill the full diameter of the well, as respectively claimed, with a reasonable expectation of success, in order to seal the well.
Conclusion
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/ANURADHA AHUJA/Primary Examiner, Art Unit 3674
