Method for determining horizontal well fracture cluster spacing and apparatus therefor

Abstract

The application discloses a method, device and machine readable storage medium for determining horizontal well fracturing hole cluster spacing, and relates to the technical field of oil and gas field development. The method comprises the following steps: determining the stress shadow of a fracturing hole cluster of a target fracturing section according to a well logging curve and a net pressure fracture fitting result; determining the influence distance of the stress shadow of the fracturing hole cluster according to the stress shadow; determining the fracture spacing corresponding to the mass transfer distance of oil and gas flowing from a matrix to a fracture of the target fracturing section according to the well logging curve, rock sample compression experimental data, fluid sample compression experimental data and fluid viscosity experimental data; and determining the fracturing hole cluster spacing according to the minimum value between the influence distance and the fracture spacing. The method can reasonably determine the cluster spacing of adjacent fracturing hole clusters.

Description

Technical Field

[0001] This application relates to the field of oil and gas field development technology, and more specifically to a method, apparatus and machine-readable storage medium for determining the spacing of fracturing hole clusters in horizontal wells. Background Technology

[0002] Multistage fracturing has become a key technology for unconventional reservoir development. Among these technologies, the perforation spacing of horizontal wells is a crucial parameter in the volumetric fracturing design of unconventional oil and gas reservoirs, significantly impacting fracturing stimulation. Optimized design of horizontal well fracturing cluster spacing has significant theoretical value and practical application in the field, effectively mitigating the blind spots in segmented perforation placement. Therefore, determining the optimal fracturing perforation cluster spacing has always been a challenge in oilfields. This issue is particularly critical in well completion design for tight reservoirs. The methods for optimizing cluster spacing vary depending on the region and lithology of the horizontal well. Typically, optimizing the number and location of clusters is achieved through numerical simulation; however, this is a time-consuming and subjective process, and the resulting methods often fail to fully consider reservoir characteristics. Summary of the Invention

[0003] The purpose of this application is to provide a method, apparatus, and machine-readable storage medium for determining the spacing of fracturing hole clusters in horizontal wells, in order to solve the technical problem in the prior art that the reservoir characteristics are not fully considered and the spacing of fracturing hole clusters cannot be reasonably determined.

[0004] To achieve the above objectives, a first aspect of this application provides a method for determining the spacing between fracturing holes in a horizontal well, comprising:

[0005] Acquire the logging curves of the target fractured section, the net pressure fracture fitting results of the target fractured section, the rock sample compression test data of the target fractured section, and the fluid sample compression test data and fluid viscosity test data of the target fractured section.

[0006] Based on the well logging curves and net pressure fracture fitting results, the stress shadow of the fracture pore cluster in the target fracture section is determined;

[0007] The influence distance of the stress shadow of the fracturing hole cluster is determined based on the stress shadow.

[0008] Based on well logging curves, rock sample compression test data, fluid sample compression test data, and fluid viscosity test data, the fracture spacing corresponding to the mass transfer distance of oil and gas flowing from the matrix to the fracture in the target fracturing section is determined.

[0009] The spacing between fracturing pore clusters is determined based on the minimum value between the influence distance and the fracture spacing.

[0010] In this embodiment of the application, the stress shadow of the fractured pore cluster of the target fractured section is determined based on the fitting results of the logging curve and the net pressure fracture. This includes: determining the stress shadow of the target fractured section by using the analytical expression of the induced stress field generated by a constant-height two-dimensional vertical fracture in a homogeneous linear elastic material, based on the fitting results of the logging curve and the net pressure fracture; or determining the stress shadow of the target fractured section by using the Buschner equation, based on the fitting results of the logging curve and the net pressure fracture.

[0011] In this embodiment, based on the well logging curve and the net pressure fracture fitting results, the stress shadow of the target fracturing section is determined using the analytical expression of the induced stress field generated by a constant-height two-dimensional vertical fracture in a homogeneous linear elastic material. This includes: determining the average Young's modulus and average Poisson's ratio of the target fracturing section based on the well logging curve; determining the average fracture width and average fracture height of the fracturing section based on the net pressure fracture fitting results; and determining the stress shadow using the analytical expression of the induced stress field generated by a constant-height two-dimensional vertical fracture in a homogeneous linear elastic material based on the average Young's modulus, average Poisson's ratio, average fracture width, and average fracture height.

[0012] In this embodiment of the application, the stress shadow of the target fracturing section is determined by the Boussiné equation based on the well logging curve and the net pressure fracture fitting result. This includes: determining the average Young's modulus of the target fracturing section based on the well logging curve and determining the average fracture width of the fracturing section based on the net pressure fracture fitting result; and determining the stress shadow of the target fracturing section based on the average Young's modulus and the average fracture width by using the Boussiné equation under coupled shear boundary conditions and porosity elasticity.

[0013] In this embodiment, the fracture spacing corresponding to the mass transfer distance of oil and gas flowing from the matrix to the fracture in the target fracturing section is determined based on well logging curves, rock sample compression test data, fluid sample compression test data, and fluid viscosity test data. This includes: determining the permeability and porosity within the fracturing section based on well logging curves; determining the rock compressibility coefficient of the rock sample based on rock sample compression test data; determining the fluid compressibility coefficient of the fluid sample based on fluid sample compression test data; and determining the fluid viscosity of the fluid sample based on fluid viscosity test data. Based on the one-dimensional diffusion equation of linear flow, the fracture spacing corresponding to the mass transfer distance is determined based on permeability, porosity, rock compressibility coefficient, fluid compressibility coefficient, and fluid viscosity.

[0014] In this embodiment, the stress shadow of the fracturing hole cluster is the stress shadow when the fracturing hole cluster has a preset number of fracturing holes open; the fracture spacing corresponding to the mass transfer distance of oil and gas flowing from the matrix to the fracture is the fracture spacing corresponding to the mass transfer distance of oil and gas flowing from the matrix to the fracture when the fracturing hole cluster has a preset number of fracturing holes open; the method further includes: obtaining the effective number of fracturing holes in the target fracturing section; determining the average effective opening rate of the fracturing hole cluster in the target fracturing section according to the ratio of the effective opening number to the preset number of fracturing holes; determining the fracturing hole cluster spacing according to the minimum value of the influence distance and the fracture spacing, including: determining the fracturing hole cluster spacing according to the product of the minimum value and the average effective opening rate.

[0015] In this embodiment of the application, obtaining the effective number of openings in the fracturing hole cluster of the target fracturing section includes: determining the effective number of openings in the fracturing hole cluster of the target fracturing section based on the logging curve of the target fracturing section.

[0016] In this embodiment of the application, based on the one-dimensional diffusion equation of linear flow, the fracture spacing corresponding to the mass transfer distance is determined according to permeability, porosity, rock compressibility coefficient, fluid compressibility coefficient, and fluid viscosity. This includes: based on the one-dimensional diffusion equation of linear flow, determining the relationship between the production life of the production well in the target fracturing section and the mass transfer distance according to permeability, porosity, rock compressibility coefficient, fluid compressibility coefficient, and fluid viscosity; and determining the fracture spacing of the production well in the target fracturing section under the target production life according to the relationship between the production life of the production well in the target fracturing section and the fracture spacing.

[0017] A second aspect of this application provides an apparatus for determining the spacing of fracturing hole clusters in a horizontal well, comprising:

[0018] The memory is configured to store instructions; and the processor is configured to retrieve instructions from the memory and, when executing the instructions, to implement the method for determining the spacing of fracturing holes in a horizontal well according to any of the foregoing embodiments.

[0019] A third aspect of this application provides a machine-readable storage medium storing instructions for causing a machine to perform a method for determining the spacing of fracturing holes in a horizontal well, according to any of the preceding embodiments.

[0020] The above technical solution can fully consider the reservoir seepage mechanics and solid mechanics characteristics to determine the stress shadow and mass transfer distance that the fluid released by the fracturing hole cluster for fracturing the soil at the target fracturing section can generate; and select the minimum value between the stress shadow and the mass transfer distance to determine the spacing between the fracturing hole clusters, so that the horizontal well in the target fracturing section can fully utilize the reservoir and maintain the adjacent fracturing hole clusters of the horizontal well at a reasonable cluster spacing.

[0021] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings:

[0023] Figure 1 The illustration schematically shows a process flow diagram of a method for determining the spacing of fracturing hole clusters in a horizontal well according to an embodiment of this application;

[0024] Figure 2 The illustration schematically shows a process flow diagram of a method for determining the spacing of fracturing holes in a horizontal well based on the effective permeability ratio, according to an embodiment of this application.

[0025] Figure 3 This schematic diagram illustrates the relationship between the production life and mass transfer distance in a one-dimensional diffusion equation for linear flow.

[0026] Figure 4 This schematically illustrates the relationship between the stress shadowing distance and the induced stress in the analytical expression of the induced stress field generated by a constant-height two-dimensional vertical crack in an isotropic homogeneous linear elastic material.

[0027] Figure 5 The diagram illustrates the relationship between the distance from the joint surface and the induced stress in the Buschner equation under coupled shear boundary conditions and porosity effect. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the embodiments of this application and are not intended to limit the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0029] It should be noted that the acquisition, transmission, storage, use, and processing of data in the technical solution of this application all comply with the relevant provisions of national laws and regulations. In the embodiments of this application, certain existing industry solutions such as software, components, and models may be mentioned. These should be considered exemplary, intended only to illustrate the feasibility of implementing the technical solution of this application, and do not imply that the applicant has already used or necessarily used such solutions.

[0030] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0031] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0032] In the process of horizontal well fracturing in oil and gas fields, perforation clusters are used to release fluids such as water into the surrounding soil to create fractures near the well, thereby enabling oil and gas extraction. In actual perforation cluster operation, if the cluster spacing is too small, the stimulated zones between the main fractures in the clusters will overlap, affecting the competition for fracture initiation and reducing fracturing efficiency. Conversely, excessively large cluster spacing will create unstimulated zones between the main fractures, affecting the reservoir's activation potential. Therefore, based on considerations of soil properties, the inventors of this application propose a method for determining the spacing of horizontal well fracturing perforation clusters based on the soil fracture conduction characteristics.

[0033] Figure 1 The illustration schematically shows a flowchart of a method for determining the spacing of fracturing hole clusters in a horizontal well according to an embodiment of this application. Figure 1 As shown in the embodiments of this application, a method for determining the spacing of fracturing hole clusters in a horizontal well is provided, which may include the following steps:

[0034] S102. Obtain the logging curves of the target fractured section, the net pressure fracture fitting results of the target fractured section, the rock sample compression test data of the target fractured section, and the fluid sample compression test data and fluid viscosity test data of the fluid sample of the target fractured section.

[0035] S104. Based on the logging curves and net pressure fracture fitting results, determine the stress shadow of the fracture pore cluster in the target fracture section;

[0036] S106. Determine the influence distance of the stress shadow of the fracturing hole cluster based on the stress shadow;

[0037] S108. Based on the logging curves, rock sample compression test data, fluid sample compression test data, and fluid viscosity test data, determine the fracture spacing corresponding to the mass transfer distance of oil and gas flowing from the matrix to the fracture in the target fracturing section.

[0038] S110. Determine the spacing between fracturing pore clusters based on the minimum value between the influence distance and the fracture spacing.

[0039] The method for determining the spacing of fractured well clusters in horizontal wells provided in this application is based on well logging curves and fracture simulations to determine the soil characteristics of the target fractured section. From this, it determines the stress shadow and fracture spacing that the fluid released from the fractured well clusters at the target fractured section can generate for fracturing the soil. The minimum value between the stress shadow and the fracture spacing is selected to determine the spacing of the fractured well clusters, thereby allowing the horizontal well in the target fractured section to fully utilize the reservoir while maintaining a reasonable cluster spacing between adjacent fractured well clusters.

[0040] In some embodiments of this application, the stress shading in step S104 can be achieved through the following steps:

[0041] Based on the well logging curves and net pressure fracture fitting results, the stress shadow of the target fracturing section is determined by the analytical expression of the induced stress field generated by the constant-height two-dimensional vertical fracture of the isotropic homogeneous linear elastic material.

[0042] Alternatively, based on the well logging curves and the net pressure fracture fitting results, the stress shadow of the target fractured section can be determined using the Businé equation.

[0043] In the above embodiments, the analytical expression for the induced stress field generated by a constant-height two-dimensional vertical crack in a homogeneous linear elastic material can be used to analyze the secondary crack distribution in the stress concentration region, and can describe the singularity of the crack tip in detail, providing a good quantitative description of the early stages of crack propagation. The Buschner equation is more suitable for far-field stress distribution and the influence of large-scale loads, and is simple to calculate with stable results. Researchers can choose between the two methods for determining stress shadows based on the soil properties of the target fracturing section and the required analysis of crack details.

[0044] In this embodiment of the application, based on the well logging curve and the net pressure fracture fitting results, the stress shadow of the target fracturing section is determined by using the analytical expression of the induced stress field generated by a constant-height two-dimensional vertical fracture in a homogeneous linear elastic material. This may include:

[0045] The average Young's modulus and average Poisson's ratio of the target fracturing section are determined based on the well logging curves, and the average fracture width and average fracture height of the fracturing section are determined based on the net pressure fracture fitting results.

[0046] Based on the average Young's modulus, average Poisson's ratio, average fracture width, and average fracture height, the stress shadow is determined by the analytical expression of the induced stress field generated by a constant-height two-dimensional vertical fracture in a homogeneous linear elastic material.

[0047] Understandably, the analytical expression for the induced stress field generated by a constant-height two-dimensional vertical crack in an isotropic homogeneous linear elastic material includes:

[0048]

[0049] Among them, σ xx For the stress perpendicular to the crack direction, p net Let θ be the net pressure within the fracture, E be the average Young's modulus within the target fracturing segment, W be the average fracture width, v be the average Poisson's ratio within the segment, and a be the fracture height. If θ, θ1, and θ2 are less than 0, then v, θ1, and θ2 are increased by π.

[0050] Based on the above formulas (1) to (10) combined, σ is determined. xx When the term is zero or a value close to 0, the value of x is the maximum distance of the stress shadow. This distance can be used as the influence distance of the stress shadow of the fracturing hole cluster in step S106 to determine the spacing of the fracturing hole cluster.

[0051] Specifically, determining the average fracture width and average fracture height of the fracturing section based on the net pressure fracture fitting results may include: determining the average fracture width and average fracture height of the fracturing section based on the production dynamic analysis of early fracturing wells and the net pressure fracture fitting results of the construction curve.

[0052] As an example, determining the average fracture width and average fracture height of the fracturing section based on the production dynamic analysis of the early-stage fracturing wells and the fitting results of the net pressure fracture curve during construction may include: determining the average fracture width of the fracturing section based on fiber optic monitoring of the early-stage fracturing wells and the fitting results of the net pressure fracture curve during construction, and determining the average fracture height of the fracturing section based on microseismic monitoring of the early-stage fracturing wells and the fitting results of the net pressure fracture curve during construction.

[0053] In some embodiments of this application, the stress shadow of the target fracturing section is determined based on the logging curves and net pressure fracture fitting results, using the Buschner equation, which may include:

[0054] The average Young's modulus of the target fracturing section is determined based on the well logging curves, and the average fracture width of the fracturing section is determined based on the net pressure fracture fitting results.

[0055] Based on the average Young's modulus and the average fracture width, the stress shadow of the target fracturing segment is determined by coupling shear boundary conditions and the Buschner equation under the porosity effect.

[0056] Understandably, the Buschner equation under coupled shear boundary conditions and porosity effect can be, for example, as follows:

[0057]

[0058] Where σ is the stress term, Z is the distance from the crack surface, E is the average Young's modulus within the segment, w is the average width of the hydraulic fracturing crack, and t is the variable transverse crack index. To meet the solution of ideal linear elastic fully coupled deformation, the upper limit of the transverse crack stress index t is 2; the lower limit is 1, which means that very strong interference occurs between adjacent cracks. Fiber optic distributed temperature and distributed sound (DTS / DAS) tests, as well as other diagnostic tests injected into densely packed cracks, all indicate that a transverse crack stress index of 1.2 is most suitable, and t is generally most appropriate at 1.2.

[0059] Based on formula (11), the Z value when σ is zero is the maximum distance of stress shadow determined by the Buschner equation under coupled shear boundary conditions and porosity effect. This distance can be used as the influence distance of stress shadow of the fracturing hole cluster in step S106 to determine the spacing of the fracturing hole cluster.

[0060] In some embodiments of this application, step S108 may include:

[0061] The permeability and porosity within the fracturing section are determined based on the well logging curves; the rock compressibility coefficient of the rock sample is determined based on the rock sample compression test data; the fluid compressibility coefficient of the fluid sample is determined based on the fluid sample compression test data; and the fluid viscosity of the fluid sample is determined based on the fluid viscosity test data.

[0062] Based on the one-dimensional diffusion equation of linear flow, the fracture spacing corresponding to the mass transfer distance is determined according to permeability, porosity, rock compressibility coefficient, fluid compressibility coefficient and fluid viscosity.

[0063] Understandably, the one-dimensional diffusion equation for linear flow can be, for example, as follows:

[0064]

[0065] Where τ is the preset production life, l is the mass transfer distance, and κ = k / (φB) f +B r η is the hydraulic diffusivity; B f B is the fluid compressibility coefficient; r η is the rock compressibility coefficient; φ is the rock porosity; η is the fluid viscosity of oil and gas; k is the rock permeability; L is the fracture spacing; and α is the power function exponent of linear flow production time and fracture spacing. Based on formula (12), the corresponding fracture spacing L can be obtained after determining the preset linear flow production years.

[0066] Specifically, compression test data for fluid samples can be obtained through PVT (pressure-volume-temperature) experiments and isothermal compression tests; compression test data for rock samples can be obtained through core compression tests and triaxial compression tests; fluid viscosity test data can be obtained through capillary viscometer tests and rotational viscometer tests. α can be determined by the slope of the time-yield and mass balance time on a double logarithmic plot of bilinear flow and linear flow in formation fractures, and its value can be, for example, 2 or 4.

[0067] In some embodiments of this application, based on the one-dimensional diffusion equation of linear flow, the fracture spacing corresponding to the mass transfer distance is determined according to permeability, porosity, rock compressibility, fluid compressibility, and fluid viscosity, which may include:

[0068] Based on the one-dimensional diffusion equation of linear flow, the relationship between the production life of the production well and the mass transfer distance of the target fracturing section is determined according to permeability, porosity, rock compressibility coefficient, fluid compressibility coefficient and fluid viscosity.

[0069] Based on the relationship between the production well life and mass transfer distance of the target fracturing section, determine the fracture spacing corresponding to the mass transfer distance of the production well in the target fracturing section under the target production life.

[0070] In the above embodiments, referring to formula (12), there is a correlation between the preset production years and the feature diffusion distance. Therefore, according to formula (12), the following can be plotted: Figure 3 The relationship curve between production years and mass transfer distance is shown. Therefore, the staff can select an appropriate production well life to determine the mass transfer distance of the target fracturing section and determine the fracture spacing corresponding to the mass transfer distance based on formula (12).

[0071] In some embodiments of this application, the stress shadow of the fracturing hole cluster in step S104 is the stress shadow when the fracturing hole cluster has a predetermined number of open fracturing holes; the fracture spacing corresponding to the mass transfer distance of oil and gas flowing from the matrix to the fracture in step S108 is the fracture spacing corresponding to the mass transfer distance of oil and gas flowing from the matrix to the fracture when the fracturing hole cluster has a predetermined number of open fracturing holes. For the method for determining the spacing of fracturing hole clusters in horizontal wells provided in the embodiments of this application, please refer to... Figure 2 It may also include:

[0072] S202. Obtain the effective number of fracturing hole clusters in the target fracturing section;

[0073] S204. Determine the average effective opening rate of the fracturing hole cluster in the target fracturing section based on the ratio of the effective number of openings to the preset number of fracturing holes.

[0074] Step S110 may include:

[0075] S112. Determine the spacing of the fracturing pore clusters based on the product of the minimum of the influence distance and the fracture spacing and the average effective opening ratio.

[0076] In determining the influence distance and mass transfer distance, a predetermined number of fracturing hole clusters is typically used. Since changes in the number of fracturing hole clusters directly affect the ability of the fracturing fluid to expand into the soil, thus altering the influence distance and mass transfer distance, the method for determining the spacing of fracturing hole clusters in horizontal wells provided in this application can adjust the spacing based on the ratio of the effective number of holes in the target fracturing section to the predetermined number of fracturing holes. Therefore, if the operator determines the spacing of the fracturing hole clusters in the target fracturing section, then in other fracturing sections with similar or identical soil properties to the target fracturing section, the spacing of the target fracturing section can be directly corrected based on the number of holes in its fracturing hole clusters to obtain the corrected spacing. This corrected spacing can then be applied to other fracturing sections with similar or identical soil properties to determine the spacing of the fracturing hole clusters in horizontal wells.

[0077] In some embodiments of this application, the determination of the effective number of openings in step S202 may include: determining the effective number of fracturing hole clusters in the target fracturing section based on the logging curve of the target fracturing section.

[0078] The following is an example illustrating the overall process of the method for determining the spacing of fracturing hole clusters in a horizontal well, as provided in the embodiments of this application.

[0079] First, for each specified fracturing section, the cluster spacing within a single section is determined based on the stress shadow of hydraulic fracturing and the mass transfer distance formula for oil and gas flowing from the matrix to the fracture.

[0080] Specifically, the fracturing section can be divided into at least one segment based on the distribution of the fracturing effect evaluation index of the fracturing section of the horizontal well with volumetric fracturing, and the reservoir types of adjacent segments can be different; the cluster spacing corresponding to each reservoir type can be determined respectively.

[0081] The aforementioned fracturing effect evaluation index characterizes the potential fracturing effect of the reservoir. For example, the fracturing effect evaluation index can be classified for each segment. There are two types of indicators for the fracturing effect evaluation index: reservoir quality and engineering quality. Segments with a fracturing effect evaluation index of "GG" within the preset range, i.e., both reservoir quality and engineering quality are "GOOD", are classified as Class I reservoirs. Segments with fracturing effect evaluation indices of "GB" and "BG", i.e., one of the reservoir quality and engineering quality is "GOOD" and the other is "BAD", are classified as Class II reservoirs. Segments with a fracturing effect evaluation index of "BB", i.e., both reservoir quality and engineering quality are "BAD", are classified as Class III reservoirs.

[0082] Then, the cluster spacing for each reservoir type is determined separately. Let's take the determination of the cluster spacing for one reservoir type as an example.

[0083] The cluster spacing within a single segment is determined based on the stress shadow of the hydraulic fracturing fracture and the mass transfer distance formula for oil and gas flowing from the matrix to the fracture. The stress shadow of the hydraulic fracturing fracture is determined by the analytical expression (plane strain condition) of the induced stress field generated by the constant-height two-dimensional vertical fracture as shown in formulas (1) to (10) or by the Buschner equation as shown in formula (11). The effective mass transfer distance formula includes the linear flow one-dimensional diffusion equation as shown in formula (12).

[0084] Determine the distance A within a single segment where there is no stress shadow effect; determine the crack spacing B corresponding to the seepage mass transfer distance within a single segment over a fixed production life.

[0085] The analytical expression for the stress field induced by the constant height two-dimensional vertical crack mentioned above can be based on linear elastic theory, and there is no shear surface or porosity effect. The Buschner equation can be based on linear elastic homogeneous isotropic medium and can fully characterize the stress shadow after the pump stops.

[0086] The distance A without stress shadow influence can be determined by the value that approaches 0 in the analytical expression of the stress field induced by the two-dimensional vertical crack at constant height in formula (1), or by the value that approaches 0 in the Buschner equation in formula (11).

[0087] According to experimental data, the rock compressibility coefficient of a certain oil well in a certain oilfield block is 6×10. -11 Pa -1 Fluid compressibility coefficient 3×10 -8 Pa -1 Fluid viscosity 3.5 × 10⁻⁶ -5 Pa·s, the logging curve in a certain fractured section shows an average permeability of 1 microdarcy, an average porosity of 0.09, an average Young's modulus of 40 GPa, and an average Poisson's ratio of 0.2. Based on the previous analysis of the production dynamics of fractured wells and fracture fitting, the hydraulic fracture height is 20 m and the fracture width is 0.008 m. Calculated using formulas (1) to (10), for example... Figure 4 As shown, when the distance from the crack surface is 40m, the induced stress is very small and the variation range is also smaller, so the minimum distance of the stress-free shadow is 40m. Or it can be calculated by formula (11), for example. Figure 5 As shown, when the distance from the crack surface is 40m, the induced stress is very small and the change range is also small, so the minimum distance of the stress-free shadow is 40m.

[0088] The seepage and mass transfer distance within a fixed production life of a single section can be the mass transfer distance corresponding to the fast-average production life of oil and gas wells in that development area. For example... Figure 3As shown, if the general production life of an oil and gas well is 3 years, then the mass transfer distance is 30m. Therefore, the fracture spacing corresponding to this mass transfer distance can be obtained by combining formula (12).

[0089] After obtaining the distance A (without stress shading) and the crack spacing B (corresponding to the mass transfer distance within a fixed production life), the minimum of these two values ​​is multiplied by the perforation opening rate to obtain the engineering cluster spacing. For example, taking the smaller of A and B as 30m, and based on the experience of a 60% perforation opening rate in the development block, the engineering cluster spacing is 18m.

[0090] This application also provides an apparatus for determining the spacing of fracturing hole clusters in a horizontal well, which may include: a memory and a storage device.

[0091] The memory is configured to store instructions. The processor is configured to retrieve instructions from the memory and, when executing the instructions, to implement the method for determining the spacing of fracturing holes in a horizontal well according to any of the foregoing embodiments.

[0092] This application also provides a machine-readable storage medium storing instructions that cause a machine to perform the method for determining the spacing of fracturing holes in a horizontal well, as provided in any of the above embodiments.

[0093] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0094] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0095] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0096] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0097] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0098] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0099] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0100] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0101] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for determining horizontal well fracture cluster spacing, characterized by, The method comprises: obtaining a well logging curve of a target fracturing section, a net pressure fracture fitting result of the target fracturing section, rock sample compression experimental data of the target fracturing section, and fluid sample compression experimental data of the target fracturing section and fluid viscosity experimental data of the fluid sample; determining a stress shadow of a fracturing hole cluster of the target fracturing section according to the well logging curve and the net pressure fracture fitting result; determining an influence distance of the stress shadow of the fracturing hole cluster according to the stress shadow; determining a fracture spacing corresponding to a mass transfer distance of oil and gas flowing from a matrix to a fracture of the target fracturing section according to the well logging curve, the rock sample compression experimental data, the fluid sample compression experimental data, and the fluid viscosity experimental data; determining the fracturing hole cluster spacing according to a minimum value of the influence distance and the fracture spacing; wherein the determining the fracture spacing corresponding to the mass transfer distance of the oil and gas flowing from the matrix to the fracture of the target fracturing section according to the well logging curve, the rock sample compression experimental data, the fluid sample compression experimental data, and the fluid viscosity experimental data comprises: determining a permeability and a porosity in the fracturing section according to the well logging curve, determining a rock compression coefficient of the rock sample according to the rock sample compression experimental data, determining a fluid compression coefficient of the fluid sample according to the fluid sample compression experimental data, and determining a fluid viscosity of the fluid sample according to the fluid viscosity experimental data; determining the fracture spacing corresponding to the mass transfer distance based on a linear flow one-dimensional diffusion equation according to the permeability, the porosity, the rock compression coefficient, the fluid compression coefficient, and the fluid viscosity; wherein the linear flow one-dimensional diffusion equation is: ；（12） wherein, is the predetermined production life, is the mass transfer distance, is the hydraulic diffusivity; is the fluid compressibility; is the rock compressibility; is the rock porosity; is the fluid viscosity of the oil and gas; is the rock permeability, is the fracture spacing, is the power function exponent of the linear flow production time and the fracture spacing.

2. The method of claim 1, wherein, the determining the stress shadow of the fracturing hole cluster of the target fracturing section according to the well logging curve and the net pressure fracture fitting result comprises: determining the stress shadow of the target fracturing section through an analytical expression of an induced stress field generated by a constant-height two-dimensional vertical fracture of an isotropic homogeneous linear elastic material according to the well logging curve and the net pressure fracture fitting result; or, determining the stress shadow of the target fracturing section through Biot's equation according to the well logging curve and the net pressure fracture fitting result.

3. The method of claim 2, wherein, the determining the stress shadow of the fracturing hole cluster of the target fracturing section according to the well logging curve and the net pressure fracture fitting result comprises: determining an average Young's modulus and an average Poisson's ratio of the target fracturing section according to the well logging curve, and determining a fracturing fracture average slit width and a fracturing fracture average slit height of the fracturing section according to the net pressure fracture fitting result; determining the stress shadow through the analytical expression of the induced stress field generated by the constant-height two-dimensional vertical fracture of the isotropic homogeneous linear elastic material according to the average Young's modulus, the average Poisson's ratio, the fracturing fracture average slit width, and the fracturing fracture average slit height.

4. The method of claim 1, wherein, The stress shadow of the target fracturing section is determined according to the logging curve and the net pressure fracture fitting result by using the Buisine equation, and the method comprises the following steps: The average Young's modulus of the target fracturing section is determined according to the logging curve, and the average fracture width of the fracturing section is determined according to the net pressure fracture fitting result; The stress shadow of the target fracturing section is determined by using the Buisine equation under the coupling of the shear boundary condition and the pore elastic effect according to the average Young's modulus and the average fracture width of the fracturing section; The Buisine equation is as follows: ；（11） wherein, is a stress term, is a distance from the fracture face, is an average Young's modulus within the segment, is an average fracture width of the fracture, is a variable transverse fracture index.

5. The method of claim 1, wherein, The stress shadow of the fracturing hole cluster is the stress shadow of the fracturing hole cluster under the condition that the fracturing hole cluster has a preset number of open fracturing holes; and the fracture spacing corresponding to the mass transfer distance of the oil and gas flowing from the matrix to the fracture is the fracture spacing corresponding to the mass transfer distance of the oil and gas flowing from the matrix to the fracture under the condition that the fracturing hole cluster has a preset number of open fracturing holes. The method further comprises the following steps: An effective opening number of the fracturing hole cluster of the target fracturing section is obtained; An average effective opening rate of the fracturing hole cluster of the target fracturing section is determined according to the ratio of the effective opening number and the preset number of fracturing holes; The fracturing hole cluster spacing is determined according to the minimum value of the influence distance and the fracture spacing, and the method comprises the following steps: The fracturing hole cluster spacing is determined according to the product of the minimum value and the average effective opening rate.

6. The method of claim 5, wherein, The effective opening number of the fracturing hole cluster of the target fracturing section is obtained, and the method comprises the following steps: The effective opening number of the fracturing hole cluster of the target fracturing section is determined according to the logging curve of the target fracturing section.

7. The method of claim 1, wherein, The fracture spacing corresponding to the mass transfer distance is determined according to the permeability, the porosity, the rock compressibility coefficient, the fluid compressibility coefficient and the fluid viscosity based on the linear flow one-dimensional diffusion equation, and the method comprises the following steps: The relationship between the production well production life and the mass transfer distance of the target fracturing section is determined according to the permeability, the porosity, the rock compressibility coefficient, the fluid compressibility coefficient and the fluid viscosity based on the linear flow one-dimensional diffusion equation; The fracture spacing of the production well of the target fracturing section under the target production life is determined according to the relationship between the production well life and the fracture spacing of the target fracturing section.

8. An apparatus for determining horizontal well fracture cluster spacing, comprising: The method comprises the following steps: a memory configured to store instructions; and a processor configured to call the instructions from the memory and capable of implementing the method for determining the horizontal well fracturing hole cluster spacing according to any one of claims 1 to 7 when the instructions are executed.

9. A machine-readable storage medium, characterized in that, The machine readable storage medium stores instructions for causing a machine to execute the method for determining the horizontal well fracturing hole cluster spacing according to any one of claims 1 to 7.

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