DETAILED ACTION
Claims 1-15 are presented for examination.
Claims 1 and 9 have been amended.
This office action is in response to the amendment submitted on 22-APR-2026.
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 Arguments - 35 U.S.C. 112(b)
Applicant’s arguments with respect to 35 U.S.C. 112(b) have been fully considered and are persuasive. The rejection of 35 U.S.C. 112(b) has been withdrawn.
Response to Arguments - 35 U.S.C. 101
On pgs. 6-9 of the Applicant’s Arguments/Remarks dated 04/22/2026 (hereinafter ‘Remarks’), Applicant argues the amended claims are patent eligible under 35 U.S.C. 101. Examiner respectfully disagrees.
On pg. 6 of the Remarks, Applicant emphasizes the amended limitations. Examiner notes the claim language “to predict induced tensile stress bulbs around fracture tips” and “for optimizing the drilling-fracturing sequence” are interpreted as intended use. However, the rejection is updated below to address the claim language if the limitation is interpreted as having patentable weight. On pg. 7 of the Remarks, Applicant agues paragraph [0040] of the specification as filed. Two portions of the paragraph are given emphasis. The first portion “describes drilling and fracturing sequences for stimulating multiple horizontal wells in the field” is related to the limitation “drilling and fracturing the group of wells using the drilling-fracturing sequence” where the “drilling and fracturing the group of wells” is interpreted as post solution activity under Step 2A prong 2 and the determination of the “drilling-fracturing sequence” is evaluated under Step 2A prong 1 as an abstract idea with the details below in the rejection. The second emphasized portion reads “This can lead to the achievement goal of using tensile stress bulbs to reduce injection fluid volume 888, generate symmetric fractures 810, and optimize well spacings” (emphasis added by Examiner). These elements recited are not necessarily present unless recited in the claim per the “this can” recited in the specification. The claim does not recite injection fluid volume and how this would be incorporated into the evaluation. The claim recites “to generate symmetric fractures”, however, the claim does not recite any condition of how the “symmetric fractures” are evaluated. No condition is set if the model does not accomplish the symmetry desired. The claim recites a “target fracture length”. This does not lead to the fractures being symmetric. The “optimize well spacings” is not recited in the claim. The “optimum pump schedule” is determined for the “well spacing”. The “well spacing” itself is not optimized. The discussion of these elements should not be interpreted as the claims being eligible if the elements are incorporated into the claim. If the elements are incorporated into the claim, further analysis is required.
On pg. 8 of the Remarks, Applicant argues paragraphs [0042] and [0043] of the specification as filed. Applicant provides additional arguments stating “As claimed, the independent claims 1 and 9 describe a specific technique for drilling and fracturing wells that achieves a particular physical result-symmetric fractures with respect to each wellbore-by utilizing a specific physical phenomenon-tensile stress bulbs around fracture tips.” Examiner interprets Applicants argument as finding the symmetric fractures as the improvement, where the symmetric fractures are based on the tensile stress bulbs around fracture tips. Examiner respectfully disagrees the invention leads to symmetric fractures. In paragraph [0042] “The same pattern of drilling and fracturing sequences in the field can be followed, which can lead to symmetric fractures for each wellbore” (Emphasis by Examiner). The symmetric factures are not achieved in every embodiment claimed, but rather a desired outcome. The invention as claimed does not provide for any limitations which check the symmetry of the fracture before drilling. In paragraph [0043] “In practice, symmetric fracture geometries are strongly desired, as these geometries can deliver the uniform drainage radius for production in the field”. The symmetric fractures are desired, but not required when performing the drilling. The invention provides a “drilling-fracturing sequence”, which is an abstract idea that can be performed mentally.
On pg. 9 of the remarks, Applicant argues the following “Under Step 2B, the specific combination of features of claims 1 and 9, including the drilling-fracturing sequence that initially skips fracturing of a drilled well adjacent to a fractured well and generates symmetric fractures by utilizing tensile stress bulbs to reduce fracture propagation resistance, represents a specific, unconventional arrangement of steps that achieves a technical improvement over conventional fracturing sequences.” Examined respectfully disagrees the claim recite a technical improvement where symmetric fractures are generated and the invention of determining a “drilling-fracturing sequence” is an abstract idea under Step 2A Prong 1. The Applicant further agues the limitation “drilling and fracturing the group of wells using the drilling-fracturing sequence” applies the judicial exception in a meaningful way. Examiner respectfully disagrees and interprets the “drilling and fracturing the group of wells” as post solution activity using the “drilling-fracturing sequence” is a generic manner. No details are provided on how the drilling and fracturing are performed.
Rejection under 35 U.S.C. 101 is maintained.
Response to Arguments - 35 U.S.C. 103
On pgs. 9-11 of the Remarks, Applicant argues the claims are patentable over the previously cited prior art.
On pg. 10, Applicant specifically argues the amended limitation:
generating a three-dimensional (3D) geomechanics model for the field by incorporating the discrete natural fracture network into the 3D grid properties of the field and the discrete natural fracture network to predict induced tensile stress bulbs around fracture tips for optimizing the drill-fracturing sequence;
As explained above in the “Response to Arguments - 35 U.S.C. 101”, “to predict” and “for optimizing” are interpreted as intended use. However, the rejection has been updated to reject the claims as if the limitations are given patentable in order to advance prosecution.
The pervious rejection under 35 U.S.C. 103 has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of
Xia et al., “A New Perspective on Multistage Stimulation of Multiple Horizontal Wells” [2016] (hereinafter ‘Xia’) in view of
Maxwell, United State Patent 10,352,145 B2 (hereinafter ‘Maxwell’) in view of
Haimson, “A Simple Method for Estimating In Situ Stresses at Great Depths” [1974] (hereinafter ‘Haimson’) further in view of
HABERFIELD et al., “Relationship between fracture toughness and tensile strength for geomaterials” [1989] (hereinafter ‘HABERFIELD’).
And updated for the dependent claims as follows:
Xia in view of Maxwell in view of Haimson further in view of HABERFIELD further in view of
Castineira et al., “Augmented AI Solutions for Heavy Oil Reservoirs: Innovative Workflows That Build from Smart Analytics, Machine Learning And Expert-Based Systems” [2018] (hereinafter ‘Castineira’).
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.
Claims 1-15 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 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.
The following limitation found in claim 1 and similarly in claim 9, has been rejected under 35 U.S.C. 112(a) as failing to comply with the written description requirement.
“the discrete natural fracture network to predict induced tensile stress bulbs around fracture tips for optimizing the drilling-fracturing sequence”
All paragraphs are cited to the specification as published.
The following are citations regarding the element “prediction”.
[0003] “A prediction is determined for a discrete natural fracture network for the field, including predicting fracture geometries, orientations, and distributions for the group of wells.”
[0026] “An important advantage of the techniques is the generation of symmetric fractures with respect to the wellbore, which is good for production prediction and reservoir management.”
[0040] “The existence of symmetric fractures can make it relatively easy to control and predict the production of a stimulated well.”
[0046] “At 1010, the breakdown pressure is estimated. At 1012, three-dimensional (3D) property modeling occurs. At 1014, natural fracture prediction occurs, including predicting fracture geometry, orientation, and distribution.”
[0051] “At 1104, a prediction is determined for a discrete natural fracture network for the field, including predicting fracture geometries, orientations, and distributions for the group of wells.”
[0071] and [0080] “A prediction is determined for a discrete natural fracture network for the field, including predicting fracture geometries, orientations, and distributions for the group of wells.”
The above paragraphs to not recite prediction of the “induced tensile stress bulbs”. The prediction is being formed for the “fracture geometries, orientations, and distributions”.
The following are citations regarding the element “tensile stress bulb”.
[0005] “Injection fluid volume can be reduced using existing tensile stress bulbs around the fracture tips of the neighboring wells and avoid stress shadow, resulting in cost reductions in the field scale. The tensile stress bulb can be fully used to optimize drilling and fracturing sequences, resulting in the generation of symmetric fractures and a reduction of injection fluid volume.”
[0012]-[0013] “FIG. 6 . is a diagram showing an example of a horizontal stress and tensile stress bulb 602 around fracture tip induced by fracture opening, according to some implementations of the present disclosure. FIG. 7 is a drawing showing an example of a sequence including an asymmetric fracture geometry due to tensile stress bulb superposition, according to some implementations of the present disclosure.”
[0022] “Techniques of the present disclosure can be used to establish several numerical models to verify the existence of using the tensile stress bulb around the fracture tips after hydraulic fracturing. The feasibility of using the induced tensile stress bulbs can be studied to optimize hydraulic fracture propagation in terms of cost, which can alleviate stress shadow issues.”
[0024] “Techniques of the present disclosure can be based on building numerical models to show the tensile stress bulbs existing around the fracture tips and the potential impact on reducing hydraulic fracture propagating resistance. Through integrating drilling and fracturing factors as a whole, drilling and fracturing sequences can be optimized together while focusing on reducing drilling times and improving fracturing results. Such techniques can lead to the development of integrated and optimal drilling and fracturing sequences, which can lead to the generation of symmetric fractures instead of asymmetric fractures on the field scale. This can improve production and reservoir field management. This can occur not only by avoiding stress shadow but also by fully using the existing tensile stress bulb around the fracture tips to reduce fracture propagation resistance propagating from the neighboring wells.”
[0033] “The areas surrounding the fracture tips can be in tension state due to fracture opening, which can form the tensile stress bulbs. The increased compression stress between the fractures can pose an issue for incoming fractures propagating from the neighboring wells, which is not good for modified zipper-fracturing method. For in-line fracturing of two neighboring wells (e.g., the zipper-fracturing method) the stress shadow issue can be avoided. The stress interference due to the existing tensile stress bulbs (see FIG. 4 ) can be used. The tensile stress bulbs can be fully used to overcome or reduce fracture propagating resistance for fracturing the neighboring wells if this advantage can be understood and utilized (see FIG. 6 ). As indicated in FIG. 6 , the areas between the two fracture tips will develop tensile stress bulbs due to tensile stress superposition. The tensile stress bulbs will attract fractures propagating relatively easily and faster toward the tensile stress bulb zone, where fracture propagating resistances are relatively lower than other areas. The existing tensile stress bulb can be good or bad depending on the fracturing sequences of the multiple horizontal wells.”
[0035]-[0037] “FIG. 4 is a diagram 400 showing an example of a horizontal stress and tensile stress bulb 402 around fracture tip induced by fracture opening, according to some implementations of the present disclosure. Stress contours 404 (e.g., measured in Pascals (Pa)) are indicated by shading. FIG. 5 is a diagram 500 showing an example of horizontal stress and tensile stress bulb 502 around fracture tip induced by fracture opening, according to some implementations of the present disclosure. Stress contours 504 (e.g., measured in Pa) are indicated by shading. FIG. 6 . is a diagram 600 showing an example of a horizontal stress and tensile stress bulb 602 around fracture tip induced by fracture opening, according to some implementations of the present disclosure.”
[0038] “FIG. 7 is a drawing showing an example of a sequence 700 including an asymmetric fracture geometry due to tensile stress bulb superposition 712, according to some implementations of the present disclosure … In a first instant 706, once Well #1 701 is fractured, tensile stress bulbs 704 are generated around the fracture tips of Well # 1 701. It is known that hydraulic fractures in rock are generally generated due to tensile failure when the induced tensile stress exceeds the minimum horizontal stress plus the tensile strength (see FIG. 4 ). A tensile stress bulb is induced in the areas surrounding the previously generated fracture tips of Well # 1 701. The induced tensile stress bulb will exist as long the fractures are not fully closed, which superimposes 706 the stress induced by subsequent fractures initiated from the neighboring Well # 2 702 … For in-line fracturing, the subsequent fractures should tend to propagate faster and longer towards the existing tensile stress bulb areas where the neighboring well is already fractured (see instant # 2 708) … After fractures communicate 714, the stress bulbs between the two wells can shrink or disappear accordingly…”
[0040] “This can lead to the achievement goal of using tensile stress bulbs to reduce injection fluid volume 808, generate symmetric fractures 810, and optimize well spacings.”
[0042] “In particular, Well #3 can be drilled second and subsequently fractured after it is drilled. As indicated in FIG. 9 , Well #1 and Well # 3 have a relatively large distance between them, and the tensile stress bulbs around each fracture tip are difficult to cause asymmetric fracture for well # 3. The fracture geometries for well # 3 will be approximately symmetric with respect to its well trajectory. Then proceed to drill well #2 and fracture it thirdly. Similar stress conditions on both sides of well # 2, the fractures will likely propagate with equal growth rates on both sides of well # 2. Therefore, symmetric fractures can be generated for well # 2, and also tensile stress bulb can be used to reduce injection fluid volume for the middle well as marked in FIG. 9.”
[0045] “In the workflow 1000, if a constant well spacing is used as determined from hydraulic fracturing modeling of a single well for a field, then the injection fluid volume for fracturing the middle well can be reduced using the existing tensile stress bulbs.”
The specification is using the “induced tensile stress bulbs” to perform analysis and using the existing bulbs. This is different from “to predict induced tensile stress bulbs”. The “induced tensile stress bulbs” are used in the analysis to determine fractures.
Claim Rejections - 35 USC § 101
35 U.S.C. 101 reads as follows:
Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title.
Claims 1-15 are rejected under 35 U.S.C. 101 because the claimed invention is directed to an abstract idea without significantly more.
Claim 1 (Statutory Category – Process)
Step 2A – Prong 1: Judicial Exception Recited?
Yes, the claim recites a mental process, specifically:
MPEP 2106.04(a)(2)(Ill) “Accordingly, the "mental processes" abstract idea grouping is defined as concepts performed in the human mind, and examples of mental processes include observations, evaluations, Judgments, and opinions.”
Further, the MPEP recites “The courts do not distinguish between mental processes that are performed entirely in the human mind and mental processes that require a human to use a physical aid (e.g., pen and paper or a slide rule) to perform the claim limitation.”
2106.04(a)(2)(I)(A) “Mathematical Relationships A mathematical relationship is a relationship between variables or numbers. A mathematical relationship may be expressed in words or using mathematical symbols. For example, pressure (p) can be described as the ratio between the magnitude of the normal force (F) and area of the surface on contact (A), or it can be set forth in the form of an equation such as p = F/A.”
2106.04(a)(2)(I)(B) “Mathematical Formulas or Equations A claim that recites a numerical formula or equation will be considered as falling within the "mathematical concepts" grouping. In addition, there are instances where a formula or equation is written in text format that should also be considered as falling within this grouping. For example, the phrase "determining a ratio of A to B" is merely using a textual replacement for the particular equation (ratio = A/B). Additionally, the phrase "calculating the force of the object by multiplying its mass by its acceleration" is using a textual replacement for the particular equation (F= ma).”
2106.04(a)(2)(I)(C) “Mathematical Calculations A claim that recites a mathematical calculation, when the claim is given its broadest reasonable interpretation in light of the specification, will be considered as falling within the "mathematical concepts" grouping. A mathematical calculation is a mathematical operation (such as multiplication) or an act of calculating using mathematical methods to determine a variable or number, e.g., performing an arithmetic operation such as exponentiation. There is no particular word or set of words that indicates a claim recites a mathematical calculation. That is, a claim does not have to recite the word "calculating" in order to be considered a mathematical calculation. For example, a step of "determining" a variable or number using mathematical methods or "performing" a mathematical operation may also be considered mathematical calculations when the broadest reasonable interpretation of the claim in light of the specification encompasses a mathematical calculation.”
determining a prediction for a discrete natural fracture network for the field, comprising predicting fracture geometries, orientations, and distributions for the group of wells;
Determining a prediction of the recited elements is an observation of those elements and then an evaluation or judgement of how the discrete natural fracture network would be presented.
generating a three-dimensional (3D) geomechanics model for the field by incorporating the discrete natural fracture network into the 3D grid properties of the field and the discrete natural fracture network to predict induced tensile stress bulbs around fracture tips for optimizing the drill-fracturing sequence;
A “three-dimensional geomechanics model” is created using “3D grid properties”. The “three-dimensional geomechanics model” is not found in the drawings. It is reasonable to interpret the three dimensions as the plane of the “discrete natural fracture network” at an associated depth. The “discrete natural fracture network” is observed and can be evaluated based on judgement. The phrase “to predicted induced tensile stress bulbs around fracture tips” is interpreted as intended use. However, if the phrase were interpreted as having patentable weight, “to predict” is interpreted as performing a judgment of the “tensile stress” and performing evaluation. Further, “for optimizing the drill-fracturing sequence” is interpreted as intended use. If the “drilling-fracturing sequence” is given patentable weight, the sequence can be determined based on judgement. Fig. 8 shows how the sequence is created and is well within the ability of a person of ordinary skill in the art to mentally determine the sequence based on experience and judgment/opinion.
conducting 3D hydraulic fracturing modeling for fracturing a single well in the field to obtain an optimum pump schedule for a target fracture length and well spacing for placing numerous horizontal wells in the field;
The determination of an optimum pump schedule is an estimation or judgment of how to produce the target fracture length and well spacing. The pump schedule is adjusted continuously until the target length and well spacing is observed.
conducting 3D hydraulic fracturing modeling for the group of wells based on a drilling-fracturing sequence configured to generate symmetric fractures and to determine an optimum pump schedule for middle wells in the group of wells considering tensile stress superposition, wherein the drilling-fracturing sequence comprises initially skipping fracturing of a drilled well adjacent to a fractured well; and
The optimum pump schedule for middle wells in the group is based on an evaluation of the stress observed from fracturing the neighboring wells.
Therefore, the claim recites a mental process.
Step 2A – Prong 2: Integrated into a Practical Solution?
MPEP 2106.05(g) Insignificant Extra-Solution Activity has found mere data gathering and post solution activity to be insignificant extra-solution activity.
The following step is merely gathering the data on elements to be used in the calculation:
estimating, using collected data and results from mini-fracking tests on previous wells, geomechanical properties for a well in a group of wells in a field, including in-situ stresses and maximum horizontal stress direction for the field;
Post solution activity:
drilling and fracturing the group of wells using the drilling-fracturing sequence.
The additional elements have been considered both individually and as an ordered combination in to determine whether they integrate the exception into a practical application.
Therefore, no meaningful limits are imposed on practicing the abstract idea.
The claim is directed to the abstract idea.
Step 2B: Claim provides an Inventive Concept?
No, as discussed with respect to Step 2A, the additional limitation is mere data gathering/post solution activity (Insignificant Extra-Solution Activity) do not impose any meaningful limits on practicing the abstract idea and therefore the claim does not provide an inventive concept in Step 2B.
Further, in regards to step 2B and as cited above in step 2A, MPEP 2106.05(g) “Obtaining information about transactions using the Internet to verify credit card transactions, CyberSource v. Retail Decisions, Inc., 654 F.3d 1366, 1375, 99 USPQ2d 1690, 1694 (Fed. Cir.2011)” is merely data gathering.
The additional elements have been considered both individually and as an ordered combination in the significantly more consideration.
The claim is ineligible.
2. The computer-implemented method of claim 1, further comprising:
collecting data for the well, including collecting drilling reports, well surveys, formation tops, and wells logs.
The elements recited are all collected prior to performing the model. MPEP 2106.05(g).
3. The computer-implemented method of claim 1, further comprising:
performing image log processing for natural fracture orientations, fracture intensity, and for maximum horizontal stress orientation for the field.
Image log processing is data collected from a well log and imported into the model. MPEP 2106.05(g)
4. The computer-implemented method of claim 1, wherein the 3D hydraulic fracturing modeling considers an injection volume for the single well.
The injection volume is evaluated based on the observed model. Step 2A Prong 1.
5. The computer-implemented method of claim 1, wherein a fracturing order for the group of wells is different from a well numbering for the group of wells.
The rearrangement of the fracturing order is based on an observation of the model and an evaluation/opinion of the correct order. Step 2A Prong 1.
6. The computer-implemented method of claim 1, wherein an injection fluid volume for a middle well drilled last in a pad is reduced by a variable α.
Reducing the volume amount by a variable is a judgement or opinion. Step 2A Prong 1.
7. The computer-implemented method of claim 6, wherein the variable α is a percentage reduction of the injection fluid volume for a first well from a pad.
Converting the variable to a percentage is an evaluation or mathematical relationship. Step 2A Prong 1.
8. The computer-implemented method of claim 7, wherein the injection fluid volume for a last well in the pad is given by (1−α)V, wherein α is a value in a range of 0.1 to 0.3, and wherein V is a volume of injection fluid for the first well in the pad.
Reducing the amount by effectively a percentage presented as a decimal is an evaluation or mathematical relationship. Step 2A Prong 1.
Claims 9-15 are system claims, containing substantially the same elements as method Claims 1-7, respectively, and are rejected on the same grounds under 35 U.S.C. 101 as Claims 1-7, respectively, Mutatis mutandis. The additional components of “one or more processors; and a non-transitory computer-readable storage medium coupled to the one or more processors and storing programming instructions for execution by the one or more processors, the programming instructions instructing the one or more processors to perform operations comprising” are interpreted as a general purpose computer and mere instructions to apply. MPEP 2106.05(f).
Claim Rejections - 35 USC § 103
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1, 3-9 and 11-15 are rejected under 35 U.S.C. 103 as being unpatentable over
Xia et al., “A New Perspective on Multistage Stimulation of Multiple Horizontal Wells” [2016] (hereinafter ‘Xia’) in view of
Maxwell, United State Patent 10,352,145 B2 (hereinafter ‘Maxwell’) in view of
Haimson, “A Simple Method for Estimating In Situ Stresses at Great Depths” [1974] (hereinafter ‘Haimson’) further in view of
HABERFIELD et al., “Relationship between fracture toughness and tensile strength for geomaterials” [1989] (hereinafter ‘HABERFIELD’).
Regarding Claim 1: A computer-implemented method, comprising:
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Xia teaches generating a three-dimensional (3D) geomechanics model for the field… (Figs. 6-7 and Pg. 2 left col last paragraph Xia “…For multiple horizontal wells in a pad, well placements hydraulic fracturing sequences, well spacing and injection volume should be optimized. Integrating these factors into a better sequence, timing and location of the events (fractures) should help to maximize the production rate in the near future. We achieve this through advanced hydraulic fracturing modeling using finite element modeling and a newly developed hydraulic fracturing simulator FrackOptima [10,11]. The unique feature of FrackOptima is its non-planar 3D fracture simulation capability…”)
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Xia teaches conducting 3D hydraulic fracturing modeling for fracturing a single well in the field to obtain an optimum pump schedule for a target fracture length and well spacing for placing numerous horizontal wells in the field; (Pg. 3 right col 1st paragraph Xia “…The strong tensile stress superposition is likely to drive the existing fractures from adjacent wells propagating further. This additional fracture growth should be taken into account for determining well spacing and pump schedule…”
Pg. 6 right col 2nd paragraph Xia “…. We first predict the hydraulic fracture length, S, using a single well hydraulic fracturing model. This fracture length will be used as baseline to define the well spacing for the multiple horizontal wells…”)
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Xia teaches conducting 3D hydraulic fracturing modeling for the group of wells based on a drilling-fracturing sequence configured to generate symmetric fractures and to determine an optimum pump schedule for middle wells in the group of wells considering tensile stress superposition, wherein the drilling-fracturing sequence comprises initially skipping fracturing of a drilled well adjacent to a fractured well; and (Pg. 6 left col last paragraph Xia “…To achieve this, we take the alternative fracturing sequence for multiple wells drilled from a pad as shown in Figure 11, which can be used to generate symmetric fractures and also take advantage of the tensile stress superposition effect. This alternative fracturing sequence will be executed following the similar pattern in the whole field scale assuming many wells are drilled from pads. In other words, after every alternating well is fractured, the wells between the fractured wells are fractured…”)
Xia does not appear to explicitly disclose
determining a prediction for a discrete natural fracture network for the field, comprising predicting fracture geometries, orientations, and distributions for the group of wells;
generating a three-dimensional (3D) geomechanics model for field by incorporating the discrete natural fracture network into the 3D grid properties of the field and the discrete natural fracture network
drilling and fracturing the group of wells using the drilling-fracturing sequence.
However, Maxwell teaches determining a prediction for a discrete natural fracture network for the field, comprising predicting fracture geometries, orientations, and distributions for the group of wells; (Col 52 lines 33-41 Maxwell “…In another aspect, the present disclosure relates to a method for using microseismic data to calibrate the initial discrete natural fracture network (DFN). The calibrated DFN model may be utilized as input for the complex hydraulic fracture network (HFN) model to simulate the fracture propagation during a fracture treatment. The calibrated DFN provides an accurate description of the reservoir and consequently a more accurate prediction of the created fracture geometry by the HFN simulator…”
Col 30 lines 9-19 Maxwell “…Predicting fracture geometry 2354 may be performed, for example, by 2360 modeling fractures, such as natural, hydraulic, and/or complex fractures, based on the wellsite data, and 2362 generating a discrete fracture network from wellsite data. The hydraulic fracture geometry may first be computed using a hydraulic fracture model based on known geological, geomechanical and fracture treatment data. In the case of complex fractures in a naturally fractured formation, the model can be used to predict the complex fracture planes, as well as the fracture width, fluid pressure and other parameters associated with the fracture system…”
Col 29 lines 51-56 Maxwell “…Additionally, from the computed stress field, the natural fractures that undergo slippage and their orientation can be determined, which can be compared to the slip orientation determined from the microseismic moment tensor to obtain more reliable interpretation…”
Col 29 lines 38-41 Maxwell “…Attempts to provide a match may be made by changing rock properties and/or initial natural fracture distribution to try to match the microseismic 40 events 2238…”)
Maxwell teaches generating a three-dimensional (3D) geomechanics model for field by incorporating the discrete natural fracture network into the 3D grid properties of the field and the discrete natural fracture network (Col 33 lines 7-29 Maxwell “…FIG. 23.2 provides another method 2300.2 of performing a fracture operation. In this version, the method involves 2350 performing a stimulation operation comprising stimulating the wellsite by injecting an injection fluid with proppant into the fracture network and 2352 generating wellsite data ( e.g. natural fracture parameters of the natural fractures, pump data, and microseismic measurements) as in FIG. 23.1. The method 2300.2 also involves 2375 modeling hydraulic fractures of the fracture network based on the wellsite data and defining a hydraulic fracture geometry of the hydraulic fractures, 2377 generating a stress field of the hydraulic fractures using a geomechanical model (e.g., 2D or 3D DDM), 2379 determining shear failure parameters comprising failure envelope and a stress state about the fracture network ( e.g., along the natural fractures, hydraulic fractures, and/or rock medium), 2381 determining a location of shear failure of the fracture network from the failure envelope and the stress state, 2383 calibrating the hydraulic fracture geometry by comparing the microseismic measurements with the simulated hydraulic fracture network and/or the activated discrete fracture network, 2385 adjusting the discrete fracture network based on the comparing, and 2387 adjusting the stimulation operation based on the comparing…”)
Maxwell teaches drilling and fracturing the group of wells using the drilling-fracturing sequence. (Col 37 lines 1-11 Maxwell “…The wellbore may be drilled according to a drilling plan that is established prior to drilling. The drilling plan may set forth equipment, pressures, trajectories and/or other parameters that define the drilling process for the wellsite. The drilling operation may then be performed according to the drilling plan. However, as information is gathered, the drilling operation may to deviate from the drilling plan. Additionally, as drilling or other operations are performed, the subsurface conditions may change. The earth model may also provide adjustment as new information is collected…”)
Xia and Maxwell are analogous art because they are from the same field of endeavor, geophysical analysis.
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have combined the generating a three-dimensional (3D) geomechanics model for the field as disclosed by Xia by determining a prediction for a discrete natural fracture network for the field, comprising predicting fracture geometries, orientations, and distributions for the group of wells and generating a three-dimensional (3D) and geomechanics model for field by incorporating the discrete natural fracture network into the 3D grid properties of the field and the discrete natural fracture network and drilling and fracturing the group of wells using the drilling-fracturing sequence as disclosed by Maxwell.
One of ordinary skill in the art would have been motivated to make this modification in order to understand natural fractures found in the formation while modeling for hydraulic fracturing as discussed in Col 1 lines 39-54 of Maxwell “…In order to facilitate the recovery of hydrocarbons from oil and gas wells, the subterranean formations surrounding such wells can be hydraulically fractured. Hydraulic fracturing may be used to create cracks in subsurface formations to allow oil or gas to move toward the well. A formation is fractured by introducing a specially engineered fluid (referred to as "fracturing fluid" or "fracturing slurry" herein) at high pressure and high flow rates into the formation through one or more wellbores. Hydraulic fractures may extend away from the wellbore hundreds of feet in two opposing directions according to the natural stresses within the formation. Under certain circumstances, they may form a complex fracture network. Complex fracture networks can include induced hydraulic fractures and natural fractures, which may or may not intersect, along multiple azimuths, in multiple planes and directions, and in multiple regions…”
Xia and Maxwell do not appear to explicitly disclose
estimating, using collected data and results from mini-fracking tests on previous wells, geomechanical properties for a well in a group of wells in a field, comprising in-situ stresses and maximum horizontal stress direction for the field;
However, Haimson teaches estimating, using collected data and results from mini-fracking tests on previous wells, geomechanical properties for a well in a group of wells in a field, comprising in-situ stresses and maximum horizontal stress direction for the field; (Abstract Haimson “…The method itself consists of pressurizing a sealed-off interval of the tested borehole until fracture occurs. Additional pumping is then undertaken to open and extend the fracture. After the pressure is released, an "impression packer" is used to obtain an oriented imprint of the hole showing the inclination and azimuth of the hydraulic fracture. Using the recorded fracturing pressures and the fracture impression, the principal stresses and their directions are calculated. Laboratory experimental work has confirmed most of the theoretical assumptions and results. Stresses calculated from field hydraulic fracturing tests have demonstrated the great potential of the method. In particular, a hydraulic fracturing test was conducted at 6280 ft (1915 m) below the surface at Rangely, Colo. The in situ stresses as determined by the method were in accord with the expected condition for the type and the slip direction of an existing fault, and were used to predict the critical pore pressure necessary to trigger local earthquakes. Following the successful experiment, more field tests have been planned…”
Pg. 158 3rd paragraph Haimson “…It is assumed that the rock is brittle, linearly elastic, homogeneous, isotropic, and porous, and that the fluid flow through the pores obeys Darcy's law. It is also assumed that one of the principal in situ effective stresses (σzz) acts in a direction parallel with the axis of the borehole to be tested. Consequently, the other two (σxx, σyy) are in a plane normal to the borehole…”
Pg. 160 2nd paragraph Haimson “…Equations 1 and 3 or 2 and 3 provide unique solutions to the principal stresses σxx and σyy. In vertical boreholes the third principal stresses σzz) can be estimated from the weight of the underlying rock…”)
Xia, Maxwell, and Haimson are analogous art because they are from the same field of endeavor, geophysical analysis.
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have combined the generating a three-dimensional (3D) geomechanics model for the field as disclosed by Xia and Maxwell by estimating, using collected data and results from mini-fracking tests on previous wells, geomechanical properties for a well in a group of wells in a field, including in-situ stresses and maximum horizontal stress direction for the field as disclosed by Haimson.
One of ordinary skill in the art would have been motivated to make this modification in order to better improve the estimation of the stresses as discussed on pg. 180 last paragraph – 181 1st paragraph of Haimson “…Hydraulic fracturing is a simple method of estimating stresses in hard rock at any depth accessible to a borehole. The theory behind this technique is well established, and the tools necessary to take measurements are readily available. The extensive laboratory research effort thus far undertaken has clearly shown that the method is particularly sensitive to in situ stresses and rather insensitive to rock properties. However, for best estimates of a1111 magnitude property testing of rocks subjected to hydraulic fracturing is recommended. The limited field testing carried out to date has been successful and encouraging. In unbroken rock vertical fractures have been obtained almost exclusively, and indications are that broken rock can be lined to yield the same results. A weakness of the method has been its inability to detect fracture orientation away from the borehole. But even in the cases where the possibility exists that the fracture changed directions while extending, the amount of information gained from a hydraulic fracturing test is generous and will often justify the expenses incurred. Specifically hydraulic fracturing can be used at depths and under in situ stress conditions where no other method is available. The success of the Rangely test is amplified when one considers that this was probably the first attempt to determine from the surface in situ stress conditions more than one mile deep…”
Xia, Maxwell, and Haimson do not appear to explicitly disclose
to predict induced tensile stress bulbs around fracture tips for optimizing the drilling-fracturing sequence;
However, HABERFIELD teaches to predict induced tensile stress bulbs around fracture tips for optimizing the drilling-fracturing sequence (Pg. 48 left col 3rd paragraph HABERFIELD “…As the applied load is increased, plasticity theory predicts that a bulb of sheared material will be formed below the footing or pile tip. Since weak rock dilates considerably (Johnston 1988), the volume of this sheared zone must increase, which in turn imparts tensile stresses into the elastic portion of the rock mass surrounding the bulb…”)
Xia, Maxwell, Haimson, and HABERFIELD are analogous art because they are from the same field of endeavor, geophysical analysis.
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have combined the generating a three-dimensional (3D) geomechanics model for field by incorporating the discrete natural fracture network into the 3D grid properties of the field and the discrete natural fracture network as disclosed by Xia, Maxwell, and Haimson by to predict induced tensile stress bulbs around fracture tips for optimizing the drilling-fracturing sequence as disclosed by HABERFIELD.
One of ordinary skill in the art would have been motivated to make this modification in order to better understand the fracture mechanics as discussed in the abstract by HABERFIELD “It is argued that the development of significant regions of tensile stress can often lead to failure in foundation engineering, especially for foundations in weak and weathered rock. As a result, accurate predictions of performance can be obtained only if this tensile failure is accounted for. It is also argued that the methods currently used for predicting tensile failure are unsuitable and that a more realistic model of tensile failure, i.e. as predicted by fracture mechanics theory, should be adopted…”
Regarding Claim 3: Xia, Maxwell, Haimson, and HABERFIELD teach The computer-implemented method of claim 1, further comprising:
Maxwell teaches performing image log processing for natural fracture orientations, fracture intensity, and for maximum horizontal stress orientation for the field. (Col 45 lines 7-13 Maxwell “…Locations of microseismicity may be used to constrain the fracture network. For a specific stress state, complex hydraulic fracture networks can be modeled for a given discrete fracture network (DFN) of preexisting fractures. The DFN may be adjusted to match the observed extent of the microseismicity. A DFN can be constructed using formation image logs and seismically derived fractures…”)
Regarding Claim 4: Xia, Maxwell, Haimson, and HABERFIELD teach The computer-implemented method of claim 1,
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Xia teaches wherein the 3D hydraulic fracturing modeling considers an injection volume for the single well. (Pg. 5 right col 1st-2nd paragraph Xia “…Additional fracture growth of the phase I generated fractures can be observed and it is due to the same reason as mentioned above. The result further confirms the phenomena as observed in Figure 7 and Figure 8. As evidenced in the above hydraulic fracturing simulations for multistage stimulation of multiple wells, the tensile stress superposition exists in certain regions and can be used to generate additional fracture growth, which should be accounted for optimizing the volume of injection fluid. If the fracture length is designed based on the hydraulic fracturing simulation of a single well, the actual well spacing for multiple wells should be larger than the fracture length determined by single well simulation. Doing this not only can avoid fractures communicating issue, also it can effectively apply the same amount of fluid to generate a relatively longer fracture…”)
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Regarding Claim 5: Xia, Maxwell, Haimson, and HABERFIELD teach The computer-implemented method of claim 1,
Xia teaches wherein a fracturing order for the group of wells is different from a well numbering for the group of wells. (Pg. 6 right col 2nd paragraph Xia “…Then we use same pump schedule to stimulate the three wells with well spacing equal to S. The alternative fracturing sequence is well #1→well #3→well #2, which is targeted to create symmetric fracture geometry relative to each wellbore. Figure 12 shows the fracture geometries after well #1 and well #3 are fractured…”)
Regarding Claim 6: Xia, Maxwell, Haimson, and HABERFIELD teach The computer-implemented method of claim 1,
Xia teaches
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wherein an injection fluid volume for a middle well drilled last in a pad is reduced by a variable α. (Pg. 6 left col last paragraph Xia “…A pump schedule with injection fluid volume V of 510m3 for well spacing 200m is obtained, which can generate the half fracture length equal to 100m (see Figure 16). The results are shown in Figure 17 and Figure 18. For this comparison study, the middle wells for both methods are injected with 67% of the injection fluid volume V used for the two side wells…”)
Regarding Claim 7: Xia, Maxwell, Haimson, and HABERFIELD teach The computer-implemented method of claim 6,
Xia teaches wherein the variable α is a percentage reduction of the injection fluid volume for a first well from a pad. (Pg. 6 left col last paragraph Xia “…A pump schedule with injection fluid volume V of 510m3 for well spacing 200m is obtained, which can generate the half fracture length equal to 100m (see Figure 16). The results are shown in Figure 17 and Figure 18. For this comparison study, the middle wells for both methods are injected with 67% of the injection fluid volume V used for the two side wells…”)
Regarding Claim 8: Xia, Maxwell, Haimson, and HABERFIELD teach The computer-implemented method of claim 7,
Xia teaches wherein the injection fluid volume for a last well in the pad is given by (1−α)V, wherein α is a value in a range of 0.1 to 0.3, and wherein V is a volume of injection fluid for the first well in the pad. (Pg. 6 right col last paragraph Xia “…As an alternative method to reduce well completion cost, the injection volume for the alternating wells in the field wide can be reduced by 33% if we keep the well spacing same as predicted by single well. Figure 15 shows the fracture initiated from middle wells are just connected with the preexisting fractures initiated from well #1 and well #3 when the middle well is injected with 67% of the pump schedule used for the two side wells. Therefore the cost reduction can be achieved through two approaches: (1) if the pump schedule is determined and used as same for all three wells, the well spacing can be increased; (2) or reduce the injection volume for the every other well if the well spacing is kept same as the one determined by hydraulic fracturing modeling of single well…”)
Claims 9 and 11-15 are system claims, containing substantially the same elements as method Claims 1 and 3-7, respectively, and are rejected on the same grounds under 35 U.S.C. 103 as Claims 1 and 3-7, respectively, Mutatis mutandis.
Claims 2 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over
Xia et al., “A New Perspective on Multistage Stimulation of Multiple Horizontal Wells” [2016] (hereinafter ‘Xia’) in view of
Maxwell, United State Patent 10,352,145 B2 (hereinafter ‘Maxwell’) in view of
Haimson, “A Simple Method for Estimating In Situ Stresses at Great Depths” [1974] (hereinafter ‘Haimson’) further in view of
HABERFIELD et al., “Relationship between fracture toughness and tensile strength for geomaterials” [1989] (hereinafter ‘HABERFIELD’) further in view of
Castineira et al., “Augmented AI Solutions for Heavy Oil Reservoirs: Innovative Workflows That Build from Smart Analytics, Machine Learning And Expert-Based Systems” [2018] (hereinafter ‘Castineira’).
Regarding Claim 2: Xia, Maxwell, Haimson, and HABERFIELD teach The computer-implemented method of claim 1, further comprising:
Xia, Maxwell, Haimson, and HABERFIELD do not appear to explicitly disclose
collecting data for the well, including collecting drilling reports, well surveys, formation tops, and wells logs.
However, Castineira teaches collecting data for the well, including collecting drilling reports, well surveys, formation tops, and wells logs. (Pg. 3 1st paragraph Castineira “…The framework requires inter-disciplinary field data including well surveys, logs, formation tops, completion and perforation data, production data, fluid contacts data, and geologic models to list a few…”
Pg. 2 2nd paragraph Castineira “…As an example, analyzing large volumes of unstructured D&C (drilling and completion) data requires a great deal of time and resources, so advanced analytics and automation are needed to process and analyze large sets of data collected before, during and after drilling operations (such as daily drilling reports, geology, mud and bit information, production and geomechanical data, etc.)…”)
Xia, Maxwell, Haimson, HABERFIELD, and Castineira are analogous art because they are from the same field of endeavor, geophysical analysis.
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have combined the generating a three-dimensional (3D) geomechanics model for field by incorporating the discrete natural fracture network into the 3D grid properties of the field and the discrete natural fracture network as disclosed by Xia, Maxwell, Haimson, and HABERFIELD by collecting data for the well, including collecting drilling reports, well surveys, formation tops, and wells logs as disclosed by Castineira.
One of ordinary skill in the art would have been motivated to make this modification in order to improve the analysis of the reservoir as discussed in the abstract of Castineira “…We built an integrated view of the reservoir through a series of smart metrics and KPIs. This was accomplished by integrating expert-based knowledge with the analysis of geological data, reservoir behavior and production and operational performance. Our analytics-based solutions were designed from the perspective of reservoir management, and consequently, they could assimilate production and cost/economic analysis with geological information (e.g., well logs and/or existing geological models) and reservoir performance (metrics for pressure, voidage, fractional flow, reservoir contact, etc.). From here, KROs (key recovery obstacles) were identified for this heavy oil field, and robust field development opportunities (i.e., behind-pipe opportunities and/or new well targets) were methodically proposed based on an innovative saturation mapping approach…”
Claims 10 is a system claim, containing substantially the same elements as method Claim 2, respectively, and are rejected on the same grounds under 35 U.S.C. 103 as Claim 2, respectively, Mutatis mutandis.
Conclusion
Claims 1-15 are rejected.
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Einstein et al., “Complete laboratory experimentation on hydraulic fracturing” [2018] – Reference discloses the term “mini-frac”, but does not teach the technique referring back to Haimson. Pg. 18 1st paragraph. “Alternatively, or in addition, hydraulic fracturing often called mini-fracking is used to determine the stress field. This technique (see e.g. Fairhurst, 1964; Haimson, 1978) has been and is being also extensively used in civil and mining engineering.”
Hoeink, US 2017/0175507 A1 – Reference discusses how incorporating a discrete natural fracture network is so well-known that further details are not discussed in the reference. [0013] “Networks of natural fractures are important contributors for fluid flow in the subsurface, and crucial in most remaining hydrocarbon reserves. However, in any realistic situation the actual physical attributes of each fracture are never known precisely. A typically used crutch employs the concept of a discrete natural fracture network (DFN), which is a discrete realization of a large number of possible realizations (ensemble) that all have the same stochastic description. Much work in the industry is focused on creating and analyzing a single (or a few at most) of those DFN's, disregarding the majority of possible realizations in the ensemble. Then, results from these singular efforts contribute to important and capital-expensive decisions. A DFN may be obtained from analysis of formation core samples and borehole logging images and sensed data such as resistivity images, nuclear magnetic resonance (NMR) images and gamma-ray data as non-limiting examples. Fracture densities, orientations and aperture distances may be extrapolated further into the formation from a borehole were the data was obtained. In that DFNs are known in the art, they are not discussed in further detail.”
Lei et al., “Modelling fluid injection-induced fracture activation, damage growth, seismicity occurrence and connectivity change in naturally fractured rocks” [2021] – Reference teaches the general concept of how natural fracture rocks and fluid injection-induced fractures are model together.
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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