Method for analyzing interference of shale gas reservoir horizontal well production on adjacent well fracturing

Abstract

The invention relates to the technical field of unconventional reservoir pressure transformation, and discloses a method for analyzing interference of shale gas reservoir horizontal well production on adjacent well fracturing in order to solve the problem that in the prior art, the analysis result is inaccurate, and therefore horizontal well fracturing construction cannot be assisted. According to the method, hydraulic fracture propagation prediction is carried out based on a constructed natural fracture model and a fracture propagation model, a methane adsorption and desorption model and a gas-liquid two-phase flow control equation are integrated, a horizontal well production seepage model is established in combination with fracture propagation data, and the reservoir pore pressure is obtained based on the horizontal well production seepage model; then, according to the initial original crustal stress field and the pore pressure, the crustal stress field of the reservoir after horizontal well production is determined; then, the initial in-situ stress field and the post-production stress field are used for hydraulic fracture extension prediction of the fractured well and comparison is carried out, and an interference analysis result can be obtained; according to the method, the accuracy of analyzing the fracturing interference of the horizontal well on the adjacent well is improved, and a guidance basis can be provided for fracturing construction of the horizontal well.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of interwell interference analysis, and particularly relates to a shale gas reservoir horizontal well production interference analysis method for adjacent well fracturing. BACKGROUND

[0002] As an important unconventional oil and gas resource, shale gas is rich in resources and widely distributed in the world. Therefore, the large-scale and efficient development of shale gas resources is of great significance to the protection of national energy security, the promotion of energy structure transformation and the development of technology. At present, due to the low porosity and low permeability characteristics of the reservoir, efficient reservoir reconstruction measures are the key to the large-scale development of shale gas reservoirs. The continuously developing horizontal well drilling technology and large-scale volume fracturing technology of horizontal wells provide important technical support for the cost reduction and efficiency improvement of shale gas reservoir development. Among them, the horizontal well group constructs an artificial fracture network with high conductivity through volume fracturing technology, increases the exposure area of the reservoir matrix and reduces the fluid seepage pressure difference, so as to improve the development efficiency of underground shale gas resources.

[0003] At present, under the well group development mode, especially for the case of reservoir infilling wells, there is interwell interference between different horizontal wells on the same platform and different platforms. The main problem is that the production of the production well reduces the reservoir energy and affects the fracturing of the well. On the one hand, interwell interference will cause repeated reconstruction of part of the target reservoir area between adjacent horizontal wells, resulting in waste of fracturing resources. On the other hand, the formation pressure depletion will affect the hydraulic fracture extension state of the fracturing well, thereby inducing interwell channeling and under-reconstruction of the target reconstruction area, and further leading to the decrease of the production of the production well and the decrease of the reconstruction effect of the fracturing well. Therefore, it is of great significance to master the interference law of shale gas reservoir horizontal well production on adjacent well fracturing for designing horizontal well group layout, optimizing horizontal well fracturing parameters and improving the overall development effect of shale gas reservoirs.

[0004] Around the problem of interwell interference of shale gas reservoirs, domestic and foreign scholars have carried out a lot of research through field operation monitoring and theoretical numerical simulation. The main aspects include the change of reservoir ground stress caused by horizontal well production, the communication mode of horizontal well fracturing, and the hydraulic fracture extension of the fracturing well adjacent to the production well. However, the existing technical solutions mainly consider the influence of reservoir pore pressure change on the evolution of reservoir ground stress, without considering the comprehensive influence of initial in-situ stress distribution and methane adsorption and desorption. At the same time, the shale reservoir in most numerical models adopts the assumption of homogeneous isotropy and the assumption of single-phase gas flow, without fully considering the influence of natural fracture development and gas-liquid two-phase flow of the reservoir, so that the interference of shale gas reservoir production well on the fracturing well lacks accurate quantitative understanding, and thus the construction basis for horizontal well fracturing cannot be provided. Therefore, based on the foregoing deficiencies, how to provide a shale gas reservoir horizontal well production interference analysis method with high accuracy for adjacent well fracturing has become a problem to be solved. Summary of the Invention

[0005] The technical problem to be solved by the present invention is the interference of horizontal well production in shale gas reservoirs on the fracturing of adjacent wells. The purpose is to provide an analysis method for the interference of horizontal well production in shale gas reservoirs on the fracturing of adjacent wells, which solves the problem of poor analysis accuracy in traditional technologies and the inability to assist horizontal well fracturing construction.

[0006] The present invention is achieved through the following technical solutions: First, a method for analyzing the interference of horizontal well production in shale gas reservoirs with adjacent well fracturing is provided, comprising: Establish a natural fracture model for shale gas reservoirs; Construct a fracture propagation model for staged multi-cluster hydraulic fracturing in horizontal wells, and obtain the first hydraulic fracture extension data in the horizontal well based on the natural fracture model and the fracture propagation model for staged multi-cluster hydraulic fracturing in horizontal wells; Establishing a methane adsorption and desorption model during shale gas reservoir production, and constructing a first gas-liquid two-phase flow control equation within the reservoir matrix of the shale gas reservoir based on the adsorption and desorption model; Based on the first gas-liquid two-phase flow governing equation and the first hydraulic fracture extension data, a horizontal well production seepage model is established. Based on the horizontal well production seepage model, the pore pressure distribution data of the reservoir in the shale gas reservoir is predicted. Obtaining an initial in-situ stress field of the shale reservoir, and determining, based on the initial in-situ stress field and the pore pressure distribution data, in-situ stress field evolution data of the shale reservoir after horizontal well production; The second and third hydraulic fracture extension data in the fractured wells were obtained by using the evolution data of the in-situ stress field of the shale reservoir and the initial in-situ stress field as boundary conditions and using the horizontal well multi-cluster fracturing fracture extension model. The inter-well interference analysis results are obtained using the second hydraulic fracture extension data and the third hydraulic fracture extension data.

[0007] Based on the above disclosure, the present application first establishes a natural fracture model of the shale gas reservoir, and then constructs a horizontal well segmented multi-cluster fracturing fracture propagation model, and based on the fracture propagation model and the natural fracture model, determines the first hydraulic fracture extension data in the horizontal well; then, a methane adsorption and desorption model in the production process of the shale gas reservoir is established, and based on the adsorption and desorption model, a first gas-liquid two-phase flow control equation in the reservoir matrix of the shale gas reservoir is constructed; then, the horizontal well production seepage model can be established according to the first gas-liquid two-phase flow control equation and the first hydraulic fracture extension data predicted in the foregoing; based on the production seepage model, the pore pressure distribution data of the reservoir in the shale gas reservoir is predicted; wherein, after obtaining the pore pressure distribution data of the reservoir, the present application combines it with the initial in-situ stress field of the shale reservoir to obtain the geostress field evolution data of the shale reservoir after the production of the horizontal well; then, the different hydraulic fracture extension data of the fracturing well adjacent to the horizontal well can be predicted by taking the foregoing geostress field evolution data and the initial in-situ stress field as the boundary conditions and using the foregoing constructed fracture propagation model; finally, the interwell interference analysis result between the horizontal well and the adjacent fracturing well can be obtained according to the hydraulic fracture extension data under the different geostress field boundary conditions.

[0008] Through the above design, the present application constructs a reasonable hydraulic fracture propagation prediction of the horizontal well based on the natural fracture model and the fracture propagation model; at the same time, the first gas-liquid two-phase flow control equation in the reservoir matrix is constructed by comprehensively considering the methane adsorption and desorption model, and the horizontal well production seepage model is established by combining the hydraulic fracture propagation prediction data, so as to obtain the pore pressure distribution data of the reservoir based on the horizontal well production seepage model; then, the geostress field evolution data of the shale reservoir after the production of the horizontal well is determined according to the initial in-situ stress field and the pore pressure distribution data; then, the hydraulic fracture extension data of the fracturing well under different geostress field boundary conditions is predicted by taking the initial in-situ stress field and the geostress field evolution data as the boundary conditions and combining the foregoing fracture propagation model; finally, the interwell interference analysis result can be obtained through the hydraulic fracture extension data under different boundary conditions; in this way, the present application considers the influence of the natural fracture on the hydraulic fracture propagation when predicting the hydraulic fracture propagation, and fully considers the comprehensive influence of the initial in-situ stress distribution, methane adsorption and desorption and gas-liquid two-phase flow when quantifying the influence of the pore pressure change on the reservoir geostress; therefore, compared with the traditional technology, the present application improves the accuracy of the horizontal well production on the adjacent well fracturing interference analysis, and can provide a guidance basis for the horizontal well fracturing construction design and optimization.

[0009] In one possible design, the natural fracture model of the reservoir in the shale gas reservoir is established, including: Obtaining geological parameters of a shale gas reservoir in which a horizontal well is located, wherein the geological parameters include natural fracture surface density, reservoir area, length of natural fractures, and azimuth angle of natural fractures; According to the natural fracture surface density and the reservoir area, a natural fracture number model is constructed; Based on the length of the natural fractures, a natural fracture length model is constructed; According to the azimuth angle of the natural fractures, a natural fracture azimuth angle model is constructed; The natural fracture number model, the natural fracture length model, and the natural fracture azimuth angle model are used to form the natural fracture model.

[0010] In one possible design, a horizontal well staged multi-cluster fracturing fracture propagation model is constructed, including: A rock deformation constitutive equation under the combined action of in-situ stress and fluid pressure of a hydraulic fracture stress field is constructed; Obtaining construction parameters and completion parameters of the horizontal well; According to the construction parameters and the completion parameters, a fracturing fluid flow control equation in the fracturing fracture propagation process of the horizontal well is constructed; The rock deformation constitutive equation and the fracturing fluid flow control equation are used to form a hydraulic fracture width and fluid pressure prediction model; Based on the hydraulic fracture width and fluid pressure prediction model, a hydraulic fracture width matrix and a fluid pressure matrix in the hydraulic fracture are calculated; According to the hydraulic fracture width matrix, the energy release rate of each hydraulic fracture tip is calculated; According to the natural fracture model, the fluid pressure matrix, and the energy release rate of each hydraulic fracture tip, a hydraulic fracture trajectory prediction model and a fracture propagation length model are constructed; The fracture propagation length model, the trajectory prediction model, and the hydraulic fracture width and fluid pressure prediction model are used to form the horizontal well staged multi-cluster fracturing fracture propagation model.

[0011] In one possible design, a rock deformation constitutive equation under the combined action of in-situ stress and fluid pressure of a hydraulic fracture stress field is constructed, including: Obtaining normal stress components and shear stress components acting on the hydraulic fracture, and a first influence coefficient matrix between the normal and the normal based on the height correction between hydraulic fractures, a second influence coefficient matrix between the shear and the shear based on the height correction, a third influence coefficient matrix between the normal and the shear based on the height correction, and a fourth influence coefficient matrix between the shear and the normal based on the height correction; According to the normal stress component, the tangential stress component, the third influence coefficient matrix and the second influence coefficient matrix, a comprehensive ground stress matrix acting on the hydraulic fracture is calculated; Based on the first influence coefficient matrix, the second influence coefficient matrix, the third influence coefficient matrix and the fourth influence coefficient matrix, a comprehensive influence coefficient matrix is calculated; Using the comprehensive ground stress matrix and the comprehensive influence coefficient matrix, the rock deformation constitutive equation based on the hydraulic fracture width and the fluid pressure in the hydraulic fracture is constructed.

[0012] In one possible design, according to the construction parameters and the completion parameters, a fracturing fluid flow control equation in the process of horizontal well fracturing fracture propagation is constructed, including: Obtaining a fracturing fluid flow coefficient matrix; According to the construction parameters and the completion parameters, the horizontal wellbore friction and perforation hole friction of each perforation cluster in the horizontal well are calculated; Based on the horizontal wellbore friction and perforation hole friction of each perforation cluster, the fracturing fluid displacement of each perforation cluster is calculated; Using the fracturing fluid flow coefficient matrix and the fracturing fluid displacement of each perforation cluster, the fracturing fluid flow control equation based on the hydraulic fracture width and the fluid pressure in the hydraulic fracture is constructed.

[0013] In one possible design, according to the adsorption and desorption model, a first gas-liquid two-phase flow control equation in the reservoir matrix of shale gas reservoir is constructed, including: Obtaining the attribute parameters of methane in the shale gas reservoir; According to the attribute parameters, a gas motion equation of methane is constructed; Based on the gas motion equation and the adsorption and desorption model, the first gas-liquid two-phase flow control equation is constructed.

[0014] In one possible design, an adsorption and desorption model of methane in the production process of shale gas reservoir is established, including: Obtaining the gas constant of methane, and the saturation load and component adsorption enthalpy of methane in the shale gas reservoir; According to the gas constant, the saturation load and the component adsorption enthalpy, and according to the following formula, the adsorption and desorption model is constructed;

[0015] In the formula, The adsorption and desorption model is represented by, The saturation load is represented by, Both represent a constant, The component adsorption enthalpy is represented by, The gas constant is represented by, Indicates temperature, represents the heterogeneity constant, Indicates gas pressure.

[0016] In one possible design, a horizontal well production seepage model is established based on the first gas-liquid two-phase flow governing equation and the first hydraulic fracture extension data, including: Obtain reservoir matrix permeability; calculating an exchange coefficient between the hydraulic fracture and the reservoir matrix based on the first hydraulic fracture extension data and the reservoir matrix permeability; constructing a second gas-liquid two-phase flow control equation in the hydraulic fracture based on the exchange coefficient; The finite volume method is used to discretize the first gas-liquid two-phase flow control equation and the second gas-liquid two-phase flow control equation to obtain the horizontal well production seepage model.

[0017] In one possible design, based on the initial in-situ stress field and the pore pressure distribution data, determining the in-situ stress field evolution data of the shale reservoir after horizontal well production includes: Obtain rock property parameters of shale reservoirs; Constructing a reservoir stress balance equation based on pore pressure changes according to the rock property parameters and the pore pressure distribution data; Solving the reservoir stress balance equation to obtain a change in reservoir stress caused by horizontal well production in a shale gas reservoir; Obtain the induced stress field generated by hydraulic fractures in the reservoir after horizontal well production in shale gas reservoirs; Stress superposition processing is performed on the initial in-situ stress field, the change value of the reservoir stress and the induced stress field, so as to obtain the in-situ stress field evolution data after the stress superposition processing.

[0018] In one possible design, the second hydraulic fracture extension data includes: a second fracture length and a second fracture width of the fractured well, and the third hydraulic fracture extension data includes a third fracture length and a third fracture width of the fractured well; The second hydraulic fracture extension data and the third hydraulic fracture extension data are used to obtain the inter-well interference analysis results, including: Calculating a first average fracture length, a first average fracture width, and a first fracture length variation coefficient based on a second fracture length and a second fracture width of the fractured well; Calculating the second average fracture length, the second average fracture width, and the second fracture length variation coefficient according to the third fracture length and the third fracture width of the fracturing well; Based on the first average seam length and the second average seam length, a seam length change rate is obtained; According to the first average slit width and the second average slit width, a slit width variation rate is obtained, and based on the first slit length variation coefficient and the second slit length variation coefficient, a slit length variation coefficient variation rate is obtained; The interwell interference analysis result is generated by using the slit length variation rate, the slit width variation rate and the slit length variation coefficient variation rate.

[0019] In a second aspect, a device for analyzing interference of shale gas reservoir horizontal well production on adjacent well fracturing is provided, comprising: A natural fracture modeling unit is configured to establish a natural fracture model of the shale gas reservoir; A hydraulic fracture prediction unit is configured to construct a horizontal well segmented multi-cluster fracturing fracture propagation model, and obtain first hydraulic fracture extension data in the horizontal well according to the natural fracture model and the horizontal well segmented multi-cluster fracturing fracture propagation model; A pore pressure prediction unit is configured to establish a methane adsorption and desorption model during shale gas reservoir production, and construct a first gas-liquid two-phase flow control equation in the reservoir matrix of the shale gas reservoir according to the adsorption and desorption model; The pore pressure prediction unit is further configured to establish a horizontal well production seepage flow model based on the first gas-liquid two-phase flow control equation and the first hydraulic fracture extension data, and predict pore pressure distribution data of the reservoir in the shale gas reservoir based on the horizontal well production seepage flow model; A geostress field evolution unit is configured to obtain an initial in-situ stress field of the shale reservoir, and determine geostress field evolution data of the shale reservoir after the horizontal well production according to the initial in-situ stress field and the pore pressure distribution data; The hydraulic fracture prediction unit is further configured to take the geostress field evolution data of the shale reservoir and the initial in-situ stress field as boundary conditions respectively, and obtain second hydraulic fracture extension data and third hydraulic fracture extension data in the fracturing well by using the horizontal well segmented multi-cluster fracturing fracture propagation model; An interwell interference analysis unit is configured to obtain an interwell interference analysis result by using the second hydraulic fracture extension data and the third hydraulic fracture extension data.

[0020] In a third aspect, another device for analyzing interference of shale gas reservoir horizontal well production on adjacent well fracturing is provided, taking the device as an electronic device for example, comprising a memory, a processor and a transceiver which are connected in sequence and communicate with each other, wherein the memory is configured to store a computer program, the transceiver is configured to transceive messages, and the processor is configured to read the computer program and execute the shale gas reservoir horizontal well production interference analysis method of the adjacent well fracturing as in the first aspect or any possible design of the first aspect.

[0021] In a fourth aspect, a storage medium is provided, and the storage medium has stored thereon instructions which, when executed on a computer, perform the method for analyzing shale gas reservoir horizontal well production interference to adjacent well fracturing as claimed in the first aspect or any possible design of the first aspect.

[0022] In a fifth aspect, a computer program product is provided, and the computer program product has instructions which, when executed on a computer, cause the computer to perform the method for analyzing shale gas reservoir horizontal well production interference to adjacent well fracturing as claimed in the first aspect or any possible design of the first aspect.

[0023] Compared with the prior art, the present application has the following advantages and beneficial effects: (1) In the prediction of hydraulic fracture propagation, the present application considers the influence of natural fractures on hydraulic fracture propagation, and in the quantification of the influence of pore pressure change on reservoir stress, the comprehensive influence of initial in-situ stress distribution, methane adsorption and desorption, and gas-liquid two-phase flow is fully considered; therefore, compared with the traditional technology, the present application improves the accuracy of the analysis of horizontal well production interference to adjacent well fracturing, and can provide guidance for the design and optimization of horizontal well fracturing construction.

[0024] (2) Based on the natural fracture model, the methane adsorption and desorption model, and the gas-liquid two-phase flow control equation in the reservoir matrix, the present application establishes a reasonable fracture propagation model and a shale gas percolation model, so that the reservoir pore pressure after horizontal well production can be accurately predicted, and the accuracy of subsequent well interference analysis can be improved.

[0025] (3) The present application considers the comprehensive influence of initial in-situ stress, production interference stress (i.e. the change value of reservoir stress caused by shale gas reservoir horizontal well production), and fracture-induced stress, and based on the stress superposition principle, the in-situ stress field evolution data of the shale reservoir are calculated; in this way, the present application can obtain reasonable and accurate in-situ stress field change data of the shale reservoir after horizontal well production, so as to provide accurate in-situ stress field boundary conditions for the subsequent analysis of the interference of the production well to the fracturing well; based on this, the accurate analysis of the interference degree of the production well to the fracturing well can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the example embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be considered as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor. In the drawings: Figure 1 The step flowchart of the method for analyzing shale gas reservoir horizontal well production interference to adjacent well fracturing provided by the embodiments of the present application; Figure 2 A natural fracture modeling result in a shale gas reservoir provided by the embodiment of the present application; Figure 3 A schematic diagram of a hydraulic fracture extension trajectory and fracture width distribution simulation result of a horizontal well staged multi-cluster fracturing provided by the embodiment of the present application; Figure 4 A schematic diagram of a reservoir pore pressure distribution result predicted by a horizontal well production percolation model provided by the embodiment of the present application; Figure 5 A schematic diagram of a horizontal maximum principal stress change result caused by horizontal well production in a shale gas reservoir provided by the embodiment of the present application; Figure 6 A schematic diagram of a horizontal minimum principal stress change result caused by horizontal well production in a shale gas reservoir provided by the embodiment of the present application; Figure 7 A schematic diagram of an induced stress distribution result of a production well hydraulic fracture along the horizontal minimum principal stress direction provided by the embodiment of the present application; Figure 8 A schematic diagram of an induced stress distribution result of a production well hydraulic fracture along the horizontal maximum principal stress direction provided by the embodiment of the present application; Figure 9 A schematic diagram of a hydraulic fracture extension trajectory and fracture width distribution result of a fracturing well under the influence of a production well provided by the embodiment of the present application; Figure 10 A schematic diagram of a hydraulic fracture extension trajectory and fracture width distribution result of a fracturing well without the influence of a production well provided by the embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the objectives, technical solutions and advantages of the present application clearer, further detailed description will be made to the present application with reference to the embodiments and the accompanying drawings, the illustrative embodiments of the present application and the description thereof are only used to explain the present application, and should not be regarded as a limitation to the present application; it should be understood that although the terms first, second, etc. can be used herein to describe various units, these units should not be limited by these terms. These terms are only used to distinguish one unit from another unit. For example, the first unit can be referred to as the second unit, and similarly, the second unit can be referred to as the first unit, without departing from the scope of the example embodiments of the present application.

[0028] Embodiment: Reference Figure 1As shown, the shale gas reservoir horizontal well production analysis method provided by the embodiment constructs a reasonable natural fracture model and a fracture propagation model to predict the hydraulic fracture propagation of the horizontal well; at the same time, a first gas-liquid two-phase flow control equation in the reservoir matrix is constructed by comprehensively considering the methane adsorption and desorption model, and a horizontal well production seepage model is established by combining the hydraulic fracture propagation prediction data, so as to obtain the pore pressure distribution data of the reservoir based on the horizontal well production seepage model; then, the in-situ stress field evolution data of the shale reservoir after the production of the horizontal well are determined according to the initial in-situ stress field and the pore pressure distribution data; then, the initial in-situ stress field and the in-situ stress field evolution data are taken as boundary conditions respectively, and the hydraulic fracture extension data of the fractured well under different in-situ stress field boundary conditions are predicted by combining the foregoing fracture propagation model; finally, the interwell interference analysis result can be obtained through the hydraulic fracture extension data under different boundary conditions; in this way, in the hydraulic fracture propagation prediction, the influence of the natural fracture on the hydraulic fracture propagation is considered, and in the quantification of the influence of the pore pressure change on the in-situ stress of the reservoir, the comprehensive influence of the initial in-situ stress distribution, the methane adsorption and desorption, and the gas-liquid two-phase flow is fully considered; therefore, compared with the traditional technology, the accuracy of the analysis of the horizontal well production on the interference of the fracturing of the adjacent well is improved, which can provide a guidance basis for the fracturing design and optimization of the horizontal well; wherein, the method can be but is not limited to running at the interwell interference analysis end; optionally, the interwell interference analysis end can be but is not limited to a personal computer or a server; it can be understood that the foregoing execution subject does not constitute a limitation on the embodiments of the present application, and correspondingly, the running steps of the method can be but are not limited to the steps S1-S7 shown below.

[0029] S1. Establish a natural fracture model of a shale gas reservoir; in specific application, the natural fracture modeling in the shale gas reservoir (i.e., the natural fracture modeling in the shale reservoir) is completed according to the geological parameters of the shale gas reservoir where the horizontal well is located and by combining a statistical method, which mainly models the number, length and orientation of the natural fractures; optionally, the natural fracture modeling process is shown in the steps S11-S15.

[0030] S11. Obtain the geological parameters of the shale gas reservoir where the horizontal well is located, wherein the geological parameters include the natural fracture surface density, the reservoir area, the length of the natural fracture and the azimuth angle of the natural fracture; in the embodiment, the foregoing geological parameters are obtained through geological exploration and are pre-stored in the interwell interference analysis end and can be called when used; after obtaining the geological parameters, the natural fracture modeling process is shown in the steps S12-S15.

[0031] S12. According to the natural fracture surface density and the reservoir area, a natural fracture number model is constructed; in a specific application, for example, but not limited to, the following formula (1) is used to construct the natural fracture number model.

[0032] (1) In the above formula (1), represents the natural fracture number, represents the natural fracture surface density, represents the reservoir area.

[0033] Wherein, the natural fracture number is used to judge the approaching angle between the hydraulic fracture and each natural fracture in the intersection criterion of the following step S27; thus, after obtaining the natural fracture number model, the natural fracture length modeling can be performed, the process of which is shown in the following step S13.

[0034] S13. Based on the length of the natural fracture, a natural fracture length model is constructed; in a specific implementation, the average fracture length and the fracture length standard deviation are calculated according to the length of the natural fracture, and then the natural fracture length model is constructed according to the average fracture length and the fracture length standard deviation; wherein, the natural fracture length model is shown in the following formula (2).

[0035] (2) In the above formula (2), represents the natural fracture length model, represents the average fracture length, represents the fracture length standard deviation, and represents that the natural fracture length model is subject to normal distribution, that is, the natural fracture length conforms to normal distribution.

[0036] Thus, after constructing the natural fracture length model, the natural fracture azimuth angle model can be constructed, the process of which is shown in the following step S14.

[0037] S14. According to the azimuth angle of the natural fracture, a natural fracture azimuth angle model is constructed; in a specific implementation, for example, but not limited to, the following formula (3) is used to construct the natural fracture azimuth angle model.

[0038] (3) In the above formula (3), represents the natural fracture azimuth angle model, represents the average azimuth angle of the natural fracture (i.e. obtained by the azimuth angle of the natural fracture in the foregoing geological parameters), represents a random constant between 0 and 1, represents a deviation coefficient.

[0039] Thus, by the aforementioned formula (1) - formula (3), the natural fracture data, length and azimuth model is constructed, and then the natural fracture model is formed based on this, and the process is shown in the following step S15.

[0040] S15. The natural fracture model is formed by using the natural fracture number model, natural fracture length model and natural fracture azimuth model.

[0041] Thus, by the aforementioned steps S11-S15, the number, length and azimuth of natural fractures are obtained, which can be used for subsequent horizontal well staged multi-cluster fracturing fracture propagation simulation under the influence of natural fractures; wherein, the fracture propagation simulation process is shown in the following step S2.

[0042] S2. The horizontal well staged multi-cluster fracturing fracture propagation model is constructed, and the first hydraulic fracture extension data in the horizontal well is obtained according to the natural fracture model and the horizontal well staged multi-cluster fracturing fracture propagation model; in specific application, the rock deformation constitutive equation of the hydraulic fracture stress field and the fracturing fluid flow control equation in the process of horizontal well fracturing fracture propagation are first constructed, and then the hydraulic fracture width and fluid pressure prediction model is constructed based on the aforementioned two models; then, the hydraulic fracture trajectory prediction model and the fracture propagation length model are constructed; finally, the horizontal well staged multi-cluster fracturing fracture propagation model is generated by combining the three models of the aforementioned width, trajectory and length.

[0043] Wherein, the specific modeling process can be but not limited to the following steps S21-S28.

[0044] S21. The rock deformation constitutive equation under the combined action of in-situ stress and fluid pressure of the hydraulic fracture stress field is constructed; in specific application, the rock deformation constitutive equation under the combined action of in-situ stress and fluid pressure of the hydraulic fracture stress field is established based on the displacement discontinuity method algorithm; wherein, the rock deformation constitutive equation is an equation about hydraulic fracture width and fluid pressure, that is, the aforementioned hydraulic fracture width and fluid pressure are unknown quantities, therefore, by establishing the equation, the solution is carried out, so as to realize the prediction of the width and fluid pressure in the hydraulic fracture after the hydraulic fracture propagation in the horizontal well.

[0045] Wherein, the construction process of the aforementioned rock deformation constitutive equation is shown in the following steps S21a-S21d.

[0046] S21a. Obtain the normal stress component and the tangential stress component acting on the hydraulic fracture, and a first influence coefficient matrix between the normal and the normal based on the fracture height correction, a second influence coefficient matrix between the tangential and the tangential based on the fracture height correction, a third influence coefficient matrix between the normal and the tangential based on the fracture height correction, and a fourth influence coefficient matrix between the tangential and the normal based on the fracture height correction.

[0047] In the embodiment, the four influence coefficient matrices and the two stress components are calculated by the displacement discontinuity method and the elastic mechanics method. Specifically, for the four influence coefficient matrices, the calculation process is as follows: (1) a geometric model of the hydraulic fracture in the shale reservoir is established (the fracture can be a one-dimensional line segment or a two-dimensional surface), and the geometric model is divided into boundary element grids (i.e. fracture grids); (2) the grid size, the distance and the positional relationship between the grids are calculated according to the node coordinates of the boundary element grids; (3) the four influence coefficient matrices, i.e. the influence coefficient matrix between the normal and the normal (describing the interaction between the normal fractures), the influence coefficient matrix between the tangential and the tangential (describing the interaction between the tangential fractures), the influence coefficient matrix between the normal and the tangential (describing the interaction between the normal fractures and the tangential fractures), and the influence coefficient matrix between the tangential and the normal (describing the interaction between the tangential fractures and the normal fractures), are calculated by using the displacement discontinuity method according to the rock mechanics parameters (Young's modulus, Poisson's ratio) of the shale reservoir and the calculation results in (2). Of course, the calculation method of the influence coefficient matrices is a common method for constructing the rock deformation constitutive relation, and the calculation process is not described herein.

[0048] Similarly, the normal stress component and the tangential stress component acting on the hydraulic fracture can be directly calculated based on the in-situ stress measurement data (i.e. the aforementioned original stress field) of the shale reservoir and the boundary element grid coordinate information. This is a general calculation method for the normal and tangential stress components, and the principle is not described herein.

[0049] Thus, after obtaining the four influence coefficient matrices and the two stress components, the comprehensive stress matrix and the comprehensive influence coefficient matrix can be calculated, and the process is shown in the following steps S21b and S21c.

[0050] S21b. Calculate the comprehensive stress matrix acting on the hydraulic fracture according to the normal stress component, the tangential stress component, the third influence coefficient matrix and the second influence coefficient matrix. In specific implementation, the following formula (4) can be used to calculate the comprehensive stress matrix.

[0051] (4) In the above formula (4), denotes the comprehensive stress matrix, denotes the normal stress component and the tangential stress component, denotes the third influence coefficient matrix and the second influence coefficient matrix.

[0052] After the comprehensive stress matrix is calculated, the calculation of the comprehensive influence coefficient matrix can be performed, and the process is shown in the following step S21c.

[0053] S21c. Based on the first influence coefficient matrix, the second influence coefficient matrix, the third influence coefficient matrix and the fourth influence coefficient matrix, a comprehensive influence coefficient matrix is calculated; in this embodiment, the comprehensive influence coefficient matrix can be calculated by using the following formula (5) for example but not limited to.

[0054] (5) In the above formula (5), denotes the comprehensive influence coefficient matrix, denotes the first influence coefficient matrix, the third influence coefficient matrix, the second influence coefficient matrix and the fourth influence coefficient matrix.

[0055] Thus, based on the aforementioned formula (4) and formula (5), after the comprehensive stress matrix and the comprehensive influence coefficient matrix are calculated, the aforementioned rock deformation constitutive equation can be constructed based thereon, and the process is shown in the following step S21d.

[0056] S21d. The rock deformation constitutive equation based on the hydraulic fracture width and the fluid pressure in the hydraulic fracture is constructed by using the comprehensive stress matrix and the comprehensive influence coefficient matrix; in specific implementation, one of the following disclosed rock deformation constitutive equations can be constructed by using the following formula (6) for example but not limited to.

[0057] (6) The above formula (6) represents the rock deformation constitutive equation, wherein, denotes the hydraulic fracture width matrix and the fluid pressure matrix in the hydraulic fracture.

[0058] Therefore, by the aforementioned steps S21a-S21d, the rock deformation constitutive equation can be constructed; at the same time, it can be known from the aforementioned formula (6) that the prediction of the hydraulic fracture width and the fluid pressure in the hydraulic fracture can be realized by solving the equation; however, there are two unknown quantities in the aforementioned formula (6), therefore, one equation cannot be solved, based on this, the present embodiment establishes a fracturing fluid flow control equation in the process of horizontal well fracturing fracture propagation, to form an equation set with the aforementioned rock deformation constitutive equation, so as to jointly solve, and obtain the width and fluid pressure matrix of the hydraulic fracture in the process of horizontal well fracturing fracture propagation.

[0059] The construction process of the fracturing fluid flow control equation is shown in the following steps S22 and S23.

[0060] S22. Obtain the construction parameters and completion parameters of the horizontal well; in this embodiment, the completion parameters may include, but are not limited to, the total number of perforation clusters in the horizontal well, the number of perforations in each perforation cluster, the perforation diameter, the inner diameter of the horizontal wellbore corresponding to each perforation cluster, and the length of the horizontal wellbore; and the construction parameters may include, but are not limited to, the fracturing fluid viscosity, the fracturing fluid density, and the fracturing fluid displacement in the horizontal wellbore corresponding to each perforation cluster, and the total fracturing fluid displacement.

[0061] Thus, after obtaining the construction parameters and completion parameters of the horizontal well, the fracturing fluid flow control equation during the horizontal well fracturing fracture propagation process can be constructed, and the process is shown in the following step S23.

[0062] S23. According to the construction parameters and completion parameters, the fracturing fluid flow control equation during the horizontal well fracturing fracture propagation process is constructed; in specific implementation, a fracturing fluid flow model during the horizontal well fracturing fracture propagation process is established, and in this embodiment, the Poiseuille law is used to describe the flow of the fracturing fluid in the hydraulic fracture, and the model can be expressed as: (7) Formula (7) represents the fracturing fluid flow model, wherein, represents time, represents the flow direction of the fluid in the hydraulic fracture, represents the hydraulic fracture width, represents the fluid pressure in the hydraulic fracture, represents the fracturing fluid viscosity of the horizontal wellbore corresponding to each perforation cluster in the construction parameters, represents the fracturing fluid displacement of the source term fracture unit, that is, the fracturing fluid displacement into each perforation cluster in the horizontal well staged multi-cluster fracturing process, The fracturing fluid filtration term of the hydraulic fracture unit can be calculated by, but not limited to, the Carter filtration model or the embedded discrete fracture model.

[0063] As can be seen from the foregoing formula (7), the fracturing fluid flow model also contains parameter terms of the hydraulic fracture width and the fluid pressure, therefore, it is necessary to solve so that the unknown parameters of formula (7) become only the hydraulic fracture width and the fluid pressure; thus, the fracturing fluid displacement of each perforation cluster is calculated, and the foregoing formula (7) is discretized, so as to establish the foregoing fracturing fluid flow control equation.

[0064] In which, for example, but not limited to, the following steps S23a-S23d can be used to establish the fracturing fluid flow control equation.

[0065] S23a. Obtain the fracturing fluid flow coefficient matrix; in specific implementation, for example, but not limited to, it can be obtained by using the finite volume method digital discrete, and pre-stored in the interwell interference analysis end, so as to directly read when constructing the fracturing fluid flow control equation; then, the horizontal wellbore friction and perforation hole friction of each perforation cluster in the horizontal well can be calculated according to the aforementioned construction parameters and completion parameters, so as to subsequently calculate the fracturing fluid displacement of each perforation cluster according to the aforementioned horizontal wellbore friction and perforation hole friction; wherein the calculation process of horizontal wellbore friction and perforation hole friction is shown in the following step S23b.

[0066] S23b. According to the construction parameters and completion parameters, the horizontal wellbore friction and perforation hole friction of each perforation cluster in the horizontal well are calculated; in specific implementation, for any perforation cluster, the horizontal wellbore friction can be calculated according to the fracturing fluid viscosity and fracturing fluid displacement in the aforementioned geological parameters, and the horizontal wellbore inner diameter and horizontal wellbore length in the completion parameters, and according to the following formula (8).

[0067] (8) In the above formula (8), represents the horizontal wellbore friction of the any perforation cluster, represents the fracturing fluid viscosity in the horizontal wellbore corresponding to the any perforation cluster, represents the length of the horizontal wellbore corresponding to the any perforation cluster, represents the inner diameter of the horizontal wellbore corresponding to the any perforation cluster, represents the fracturing fluid displacement in the horizontal wellbore corresponding to the any perforation cluster.

[0068] Similarly, for any perforation cluster, the perforation hole friction of the any perforation cluster can be calculated according to the following formula (9).

[0069] (9) In the above formula (9), represents the perforation hole friction of the any perforation cluster, represents the fracturing fluid viscosity in the horizontal wellbore corresponding to the any perforation cluster, represents the perforation erosion correction coefficient, represents the number of perforations in the any perforation cluster, represents the perforation diameter in the any perforation cluster, represents the fracturing fluid displacement into the any perforation cluster.

[0070] Thus, by the aforementioned formula (8) and formula (9), the horizontal wellbore friction and perforation hole friction of each perforation cluster can be calculated, and then, based on this, the fracturing fluid discharge of each perforation cluster can be calculated, the process of which is shown in the following step S23c.

[0071] S23c. Based on the horizontal wellbore friction and perforation hole friction of each perforation cluster, the fracturing fluid discharge of each perforation cluster is calculated; in specific applications, for example, but not limited to, the pressure balance equation of the horizontal wellbore heel is established according to the Kirchhoff law, and the fracturing fluid discharge into each perforation cluster in the horizontal well fracturing process is solved by using Newton iteration combined with the flow conservation equation.

[0072] wherein the calculation formula of the fracturing fluid discharge is: (10) In the aforementioned formula (10), represents the fracturing fluid discharge into each perforation cluster at the n+1th iteration, represents the fracturing fluid discharge into each perforation cluster at the nth iteration, represents the first intermediate parameter at the nth iteration, represents the second intermediate parameter at the nth iteration, represents the total number of perforation clusters.

[0073] wherein: (11) (12) and (13) In formula (11), in turn represent the horizontal wellbore friction, perforation hole friction of the first perforation cluster, and the inlet fluid pressure of the fracturing fluid entering the hydraulic fracture through the perforation hole in the first perforation cluster (which can be obtained according to historical data), in turn represent the horizontal wellbore friction, perforation hole friction of the second perforation cluster, and the inlet fluid pressure of the fracturing fluid entering the hydraulic fracture through the perforation hole in the second perforation cluster, in turn represent the horizontal wellbore friction, perforation hole friction of the first perforation cluster, and the inlet fluid pressure of the fracturing fluid entering the hydraulic fracture through the perforation hole in the first perforation cluster, in turn represent the horizontal wellbore friction, perforation hole friction of the first perforation cluster, and the inlet fluid pressure of the fracturing fluid entering the hydraulic fracture through the perforation hole in the first perforation cluster.

[0074] In formula (12), It represents the displacement of fracturing fluid entering each perforation cluster.

[0075] In formula (13), Indicates that at the n+1th iteration, the The fracturing fluid displacement of each perforation cluster, Indicates the total fracturing fluid displacement, Indicates that at the n+1th iteration, the The fracturing fluid displacement of each perforation cluster.

[0076] In this way, after calculating the fracturing fluid discharge rate of each perforation cluster through the aforementioned formulas (10) to (13), the fracturing fluid flow control equation can be constructed in combination with the aforementioned fracturing fluid flow coefficient matrix. The process is shown in the following step S23d.

[0077] S23d. Utilizing the fracturing fluid flow coefficient matrix and the fracturing fluid displacement of each perforation cluster, a fracturing fluid flow control equation based on the hydraulic fracture width and the fluid pressure within the hydraulic fracture is constructed. In this embodiment, the finite volume method is used to discretize the fracturing fluid flow model in the hydraulic fracture to construct the fracturing fluid flow control equation.

[0078] Optionally, the fracturing fluid flow control equation is shown in the following formula (14).

[0079] (14) In the above formula (14), represents the fracturing fluid flow coefficient matrix, Indicates the The fluid pressure matrix at Indicates the The hydraulic fracture width matrix at represents the hydraulic fracture width matrix at time t, Indicates the The hydraulic fracture unit source matrix at the time The fracturing fluid flow rate into each perforation cluster at the time Indicates the time step; of course, initially, the hydraulic fracture unit source term matrix is ​​the fracturing fluid displacement of each perforation cluster calculated above.

[0080] After constructing the fracturing fluid flow control equation through the aforementioned steps S23a to S23d, it can be combined with the aforementioned rock deformation constitutive equation to form a system of equations (i.e., the following hydraulic fracture width and fluid pressure prediction model), thereby predicting the fracture width and fluid pressure of the hydraulic fracture in the horizontal well during expansion. The construction process of the aforementioned system of equations is shown in the following step S24.

[0081] S24. A hydraulic fracture width and fluid pressure prediction model is established using the rock deformation constitutive equation and the fracturing fluid flow control equation; in this embodiment, after the hydraulic fracture width and fluid pressure prediction model is established, the width and fluid pressure of the hydraulic fracture in the horizontal well during propagation can be predicted, the process of which is shown in the following step S25.

[0082] S25. Based on the hydraulic fracture width and fluid pressure prediction model, a hydraulic fracture width matrix and a hydraulic fracture fluid pressure matrix are calculated; in specific implementation, a fluid-solid coupling nonlinear equation set (i.e., the hydraulic fracture width matrix and the hydraulic fracture fluid pressure matrix) is established by combining the rock deformation constitutive equation and the fracturing fluid flow control equation in the hydraulic fracture; then, the hydraulic fracture width matrix and the hydraulic fracture fluid pressure matrix are obtained by numerical iteration; of course, the width and fluid pressure of each hydraulic fracture at different time steps are also obtained, and the iteration solving process is not described in detail as it is a common method for solving equation sets.

[0083] After the hydraulic fracture width matrix (i.e., the first fracture width) and the hydraulic fracture fluid pressure matrix of each hydraulic fracture at different time steps are obtained, the shale reservoir hydraulic fracture propagation can be predicted based on the same, the process of which is shown in the following steps S26-S28.

[0084] S26. The energy release rate of the tip of each hydraulic fracture is calculated according to the hydraulic fracture width matrix; in specific implementation, for example, the width, Young's modulus, and Poisson's ratio of the rock of the shale reservoir can be used to calculate the energy release rate of each hydraulic fracture at different time steps under the framework of linear elastic theory; wherein the calculation formula of the energy release rate is: , wherein, represents the energy release rate of any hydraulic fracture at any time step, represents the Young's modulus, represents the Poisson's ratio of the reservoir rock, represents the tensile stress intensity factor and the shear stress intensity factor, respectively, which are calculated based on the theory of fracture mechanics using the Young's modulus, Poisson's ratio, the width obtained in the preceding step S21 (which is a common calculation technique for the tensile stress intensity factor and the shear stress intensity factor, and the principle thereof is not described in detail); thus, after the energy release rate of each hydraulic fracture in the horizontal well at different time steps is calculated based on the preceding step S26, the hydraulic fracture trajectory and the fracture propagation length model can be constructed in combination with the natural fracture model and the fluid pressure matrix of each hydraulic fracture in the horizontal well at different time steps, the process of which is shown in the following step S27.

[0085] S27. According to the natural fracture model, the fluid pressure matrix and the energy release rate of each hydraulic fracture tip, a trajectory prediction model and a fracture propagation length model of the hydraulic fracture are constructed; in this embodiment, the maximum energy release rate criterion and the maximum circumferential stress criterion are used to predict whether the hydraulic fracture in the horizontal well expands in the reservoir and the direction of expansion, wherein the calculation expressions of the expansion condition and the expansion direction are: (15) (16) In the above formula (15), represents the critical energy release rate of the hydraulic fracture expanding in the reservoir matrix, which is a preset value.

[0086] In the above formula (16), represents the hydraulic fracture expansion deflection angle, , represents the tensile stress intensity factor and the shear stress intensity factor, respectively.

[0087] Thus, when the energy release rate of any hydraulic fracture at any time step is greater than the critical energy release rate, then the fracture expansion occurs, at which time the expansion direction can be calculated according to the aforementioned formula (16).

[0088] Then, based on the natural fracture model and the aforementioned fracture width of the hydraulic fracture, and using the intersection criterion, the expansion of the hydraulic fracture after encountering the natural fracture when the hydraulic fracture expands is described, wherein the trajectory prediction model corresponding to the intersection criterion is: (17) In the above formula (17), represents the circumferential stress and shear stress of the tip stress field of any hydraulic fracture acting on the natural fracture, represents the tensile strength of the rock of the shale reservoir, represents the fracture fluid pressure at the intersection point of the any hydraulic fracture and the natural fracture (in fact, it is the fluid pressure value in the fluid pressure matrix calculated by the aforementioned hydraulic fracture width and fluid pressure prediction model), represents the shear strength of the natural fracture (a preset parameter), represents the friction coefficient of the natural fracture wall surface (a preset parameter), represents the approaching angle, and the calculation formula is , represents the azimuth angle of the natural fracture, represents the angle of the hydraulic fracture tip, represents the critical energy release rate of the any hydraulic fracture expanding along the natural fracture, represents the energy release rate of the any hydraulic fracture extending along the natural fracture direction, wherein, when greater than or equal to the hydraulic fracture begins to extend along the natural fracture; represents the angle between the hydraulic fracture and the natural fracture, represents the tensile strength of the reservoir rock, represents the horizontal minimum principal stress of the reservoir.

[0089] wherein, may be but not limited to calculated under the online elastic theory framework using the hydraulic fracture slit width, Young's modulus and Poisson's ratio, which is a common calculation method of the circumferential stress and shear stress of the hydraulic fracture acting on the natural fracture, and the calculation process is not described here; at the same time, based on the natural fracture length model in the natural fracture model, the length of any natural fracture in the reservoir is obtained, and the natural fracture length is taken as the boundary condition of the hydraulic fracture extending along the natural fracture, and the hydraulic fracture stops extending along the natural fracture when the extension reaches the natural fracture length.

[0090] Specifically, the function of the aforementioned formula (17) is: (1) to determine whether the hydraulic fracture can pass through the natural fracture: by calculating the circumferential stress and shear stress of the stress field of the hydraulic fracture tip acting on the natural fracture, and comparing it with the tensile strength of the reservoir rock and the shear strength of the natural fracture, it is determined whether the hydraulic fracture can pass through the natural fracture; (2) to determine whether the hydraulic fracture can activate the natural fracture: when the hydraulic fracture cannot pass through the natural fracture, it can be determined by the formula whether the hydraulic fracture can activate the natural fracture to become a new fracture propagation path; in this way, combined with the aforementioned formula (16), the extension direction of the hydraulic fracture can be determined when the hydraulic fracture passes through or activates the natural fracture, so as to obtain different extension trajectories; of course, the aforementioned formula (17) is for each hydraulic fracture, that is, when the slit width and other data of the tip element of different hydraulic fractures at different times are substituted, the extension trajectories of different hydraulic fractures at different time steps can be obtained.

[0091] In this way, combined with the aforementioned extension trajectory prediction model and the aforementioned extension direction (i.e. extension deflection angle), the extension trajectories of each hydraulic fracture at different time steps can be simulated; at the same time, the crack propagation length model can be constructed according to the size of the energy release rate.

[0092] wherein, the crack propagation length model is shown in the following formula (18).

[0093] (18) in formula (18), represents the slit length extension step of the jth hydraulic fracture at a time step, represents the maximum running extension step (a preset value), represents the energy release rate of the j-th hydraulic fracture energy in one time step, It represents the maximum value of the energy release rate corresponding to all hydraulic fractures in a time step, that is, ,in, Indicates the The energy release rate corresponding to each hydraulic fracture is is the total number of hydraulic fractures.

[0094] In this way, the fracture length expansion step of each hydraulic fracture at different time steps can be calculated by the aforementioned formula (18). Based on this, for any hydraulic fracture, the fracture length expansion step at all time steps is summed up and added to the original length to obtain the fracture length of any hydraulic fracture (i.e., the length of the first fracture). Then, by combining the aforementioned hydraulic fracture width and fluid pressure prediction model, the fracture width of each hydraulic fracture can be obtained.

[0095] After constructing the fracture extension length model and trajectory prediction model, the aforementioned hydraulic fracture width and fluid pressure prediction model can be combined to form a horizontal well segmented multi-cluster fracturing fracture extension model, as shown in the following step S28.

[0096] S28. Utilize the fracture extension length model, the trajectory prediction model, and the hydraulic fracture width and fluid pressure prediction model to form the horizontal well segmented multi-cluster hydraulic fracturing fracture extension model.

[0097] Through the above design, after obtaining the hydraulic fracture width and the fluid pressure in the hydraulic fracture, the energy release rate of each hydraulic fracture is calculated to determine whether each hydraulic fracture is expanding, and the aforementioned formula (16) is used to obtain the expansion direction; then, the intersection criterion is used to describe the expansion of the hydraulic fracture after encountering the natural fracture, that is, the aforementioned formula (17) is used in combination with the natural fracture model to obtain the expansion of the hydraulic fracture after encountering the natural fracture (that is, the parameters such as the azimuth angle of the natural fracture are substituted into the formula corresponding to the intersection criterion to obtain the crack expansion). Then, the aforementioned formula (1 8) to obtain the crack expansion step length; based on this, at each time step, the aforementioned hydraulic fracture expansion deflection angle and intersection criterion can be used to determine the expansion path of the hydraulic fracture. Finally, based on the fracture obtained in the previous time step, a new fracture with a corresponding fracture expansion step length and a direction of the deflection angle is added to the fracture tip of the previous time step, and the hydraulic fracture in the current time step can be obtained. Based on this, after continuous iteration and recalculation of the hydraulic fracture width and the fluid pressure in the fracture, the crack expansion direction and fracture length of the next time step can be re-determined, thereby completing the extension prediction of the hydraulic fracture.

[0098] Thus, by the foregoing steps S21-S28, the horizontal well segmented multi-cluster hydraulic fracture propagation model can be used to simulate the hydraulic fracture propagation results, i.e., to calculate the trajectory, length and width of each hydraulic fracture; and then, the foregoing length, width and fracture trajectory can be used to form the first hydraulic fracture propagation data in the horizontal well.

[0099] After the hydraulic fracture propagation prediction is completed, the reservoir pore pressure distribution data can be predicted, and the process is shown in the following steps S3 and S4.

[0100] S3. Establish a methane adsorption and desorption model in the shale gas reservoir production process, and according to the adsorption and desorption model, a first gas-liquid two-phase flow control equation in the reservoir matrix in the shale gas reservoir is constructed; in specific implementation, first, one of the construction processes of the adsorption and desorption model is disclosed, which is specifically: first, the gas constant of methane, and the saturation load and component adsorption enthalpy of methane in the shale gas reservoir are obtained; and then, the adsorption and desorption model is constructed according to the gas constant, the saturation load and the component adsorption enthalpy.

[0101] Alternatively, for example, but not limited to, the following formula (19) can be used to construct the adsorption and desorption model.

[0102] (19) In the foregoing formula (19), represents the adsorption volume of unit mass medium (in fact, it represents the adsorption volume of unit mass medium), represents the saturation load, both represent constants, represents the component adsorption enthalpy, represents the gas constant, represents the temperature, represents the heterogeneity constant, represents the gas pressure, i.e., the pressure of methane gas.

[0103] After the methane adsorption and desorption model is constructed, the first gas-liquid two-phase flow control equation in the reservoir matrix in the shale gas reservoir can be constructed based on the model; wherein, the construction process is shown in the following steps S31-S33.

[0104] S31. Obtain the attribute parameters of methane in the shale gas reservoir; in this embodiment, for example, the foregoing attribute parameters of methane can include, but are not limited to: the effective permeability of methane in the shale gas reservoir, the gas viscosity of methane, the gas phase pressure of methane and the relative permeability of methane, and the foregoing attribute parameters are all preset parameters.

[0105] After obtaining the property parameters of methane, a gas motion equation of methane can be constructed based on the property parameters, and the process is shown in the following step S32.

[0106] S32. Construct a gas motion equation of methane according to the property parameters; in specific applications, the following formula (20) can be used to construct the gas motion equation.

[0107] (20) In the above formula (20), denotes the gas motion equation, which also denotes the flow velocity of methane, denotes the relative permeability, denotes the effective permeability, denotes the gas viscosity, denotes the gas phase pressure, denotes the gradient operator.

[0108] Thus, after constructing the gas motion equation of methane based on the above formula (20), the first gas-liquid two-phase flow control equation can be constructed in combination with the adsorption and desorption model, and the process is shown in the following step S33.

[0109] S33. Construct the first gas-liquid two-phase flow control equation based on the gas motion equation and the adsorption and desorption model; in specific applications, the following formula (21) and formula (22) can be used to construct the first gas-liquid two-phase flow control equation.

[0110] (21) (22) The above formula (21) and formula (22) represent the first gas-liquid two-phase flow control equation; in formula (21), denote the flow velocities of water and methane (gas) in the reservoir matrix, respectively, denote the relative permeabilities of water and methane in the reservoir matrix, respectively, denotes the pore pressure of the reservoir matrix (unknown), denote the viscosities of water and methane in the reservoir matrix, respectively, denotes the capillary pressure in the reservoir matrix, denote the effective permeability and apparent permeability of the reservoir matrix, respectively.

[0111] In the above formula (22), denote the densities of water and methane in the reservoir matrix, respectively, denotes the effective porosity of the reservoir matrix, representing the water saturation in the reservoir matrix, representing the exchange flow rate of water between the reservoir matrix and the hydraulic fracture, and the exchange flow rate of methane between the reservoir matrix and the hydraulic fracture (the calculation process of both is described in detail in the following step S4), representing the methane adsorption amount, and t represents time.

[0112] wherein, , wherein, representing the rock density of the reservoir.

[0113] Thus, by the aforementioned steps S31-S33, the gas-liquid two-phase flow control equation in the reservoir matrix can be constructed, and then the aforementioned first hydraulic fracture extension data can be combined to establish a horizontal well production seepage model, so as to predict the pore pressure distribution data of the reservoir in the shale gas reservoir based on the horizontal well production seepage model; the construction process of the horizontal well production seepage model is shown in the following step S4.

[0114] S4. Based on the first gas-liquid two-phase flow control equation and the first hydraulic fracture extension data, a horizontal well production seepage model is established, and based on the horizontal well production seepage model, the pore pressure distribution data of the reservoir in the shale gas reservoir is predicted; in specific application, the second gas-liquid two-phase flow control equation in the hydraulic fracture also needs to be constructed, and then the first hydraulic fracture extension data obtained in the aforementioned step S2 is combined to construct the horizontal well production seepage model, wherein the construction process of the aforementioned horizontal well production seepage model can be but is not limited to the following steps S41-S44.

[0115] S41. Obtain the reservoir matrix permeability; in this embodiment, the aforementioned reservoir matrix permeability is a preset parameter, which can be read in use; and after obtaining the aforementioned data, the exchange coefficient between the hydraulic fracture and the reservoir matrix can be calculated in combination with the aforementioned first hydraulic fracture extension data, the process of which is shown in the following step S42.

[0116] S42. Calculate the exchange coefficient between the hydraulic fracture and the reservoir matrix according to the first hydraulic fracture extension data and the reservoir matrix permeability; in specific application, the exchange coefficient is calculated based on the aforementioned data and through an embedded discrete fracture model; the formula is wherein, representing the exchange coefficient between the hydraulic fracture and the reservoir matrix, multiplied by the pressure difference to calculate the exchange flow rate of methane and water between the hydraulic fracture and the reservoir matrix in step S43, representing the reservoir matrix permeability, representing the fracture length in the first hydraulic fracture extension data, and h represents the reservoir thickness (preset value), represents the equivalent normal distance between the fracture trajectory in the first hydraulic fracture extension data and the reservoir matrix. Of course, the embedded discrete fracture model is a common way to calculate the exchange coefficient between the fracture and the reservoir matrix, and its calculation process will not be repeated here.

[0117] After obtaining the exchange coefficient between the hydraulic fracture and the reservoir matrix, the gas-liquid two-phase flow control equation within the hydraulic fracture can be constructed, and the process is shown in the following step S43.

[0118] S43. Based on the exchange coefficient, a second gas-liquid two-phase flow control equation within the hydraulic fracture is constructed. In this embodiment, the second gas-liquid two-phase flow control equation can be constructed by, for example but not limited to, using the following formula (23).

[0119] (twenty three) The above formula (23) represents the second gas-liquid two-phase flow control equation, where: are the densities of methane and water in the hydraulic fracture, represents the effective porosity of the hydraulic fracture, represents the water saturation in the hydraulic fracture, are the relative permeabilities of methane and water in hydraulic fractures, represents the effective permeability of the hydraulic fracture, represent the viscosities of methane and water in hydraulic fractures, respectively. represents the new fluid pressure in the hydraulic fracture (which is the same as the pressure calculated in step S2). different), are the source terms of methane and water produced by horizontal wells (i.e., the production of methane and water), They represent the exchange rate of methane between hydraulic fractures and reservoir matrix (i.e., the cross-flow rate of methane between hydraulic fractures and reservoir matrix), and the exchange rate of water between hydraulic fractures and reservoir matrix (i.e., the cross-flow rate of water between hydraulic fractures and reservoir matrix), respectively. It is based on The exchange flow rates of methane and water are calculated by multiplying the respective pressure differences.

[0120] After obtaining the second gas-liquid two-phase flow control equation in the hydraulic fracture, the horizontal well production seepage model can be constructed in combination with the first gas-liquid two-phase flow control equation, as shown in the following step S44.

[0121] S44. Using the finite volume method, discretize the first gas-liquid two-phase flow governing equation and the second gas-liquid two-phase flow governing equation to obtain the horizontal well production seepage model.

[0122] In a specific application, the horizontal well production percolation model is as follows: (24) Equation (24) represents the horizontal well production percolation model, wherein, A1and A2represent the first flow coefficient matrix (flow coefficient matrix between reservoir matrix and hydraulic fracture) and the second flow coefficient matrix (flow coefficient matrix between hydraulic fracture and reservoir matrix) obtained by discretizing the aforementioned two gas-liquid two-phase flow control equations by finite volume method, respectively, A3and A4represent the third flow coefficient matrix between reservoir matrix and the fourth flow coefficient matrix between hydraulic fracture (constant matrix, preset parameter), respectively, P1and P2represent the reservoir matrix pore pressure matrix and the hydraulic fracture new fluid pressure matrix (unknown quantity), respectively, F1and F2represent the reservoir matrix flow source term matrix and the hydraulic fracture flow source term matrix, which can be calculated according to the bottom hole flowing pressure, methane density under standard conditions, generation time and other data, and is also pre-calculated and stored in the well interference analysis end.

[0123] Thus, the horizontal well production percolation model can be constructed through the aforementioned steps S41-S44. In this way, the gas motion equation and the methane adsorption and desorption model describe the cross-scale flow behavior and analytical adsorption phenomenon of methane in the shale reservoir, which are combined in the control equation of the first gas-liquid two-phase flow in the reservoir matrix. Then, the numerical calculation expression is obtained by discretizing the control equation of the gas-liquid two-phase flow in the hydraulic fracture using the finite volume method, and the reservoir matrix pore pressure matrix and the hydraulic fracture new fluid pressure matrix are obtained by iterative solution of the matrix. Thus, the pore pressure distribution data of the reservoir in the shale gas reservoir can be obtained based on the aforementioned equation (24).

[0124] After obtaining the pore pressure distribution data of the reservoir in the shale gas reservoir, the pore pressure distribution data can be used to determine the geostress field of the shale reservoir after the production of the horizontal well, and the process is shown in the following step S5.

[0125] S5. Obtain the initial in-situ stress field of the shale reservoir, and determine the geostress field evolution data of the shale reservoir after the production of the horizontal well according to the initial in-situ stress field and the pore pressure distribution data. In a specific application, the geostress field evolution data of the shale reservoir after the production of the horizontal well, that is, the geostress field of the shale reservoir after the production of the horizontal well, can be obtained by using the following steps S51-S55, but not limited thereto.

[0126] S51. Obtain rock property parameters of the shale reservoir; in this embodiment, the rock property parameters may include, but are not limited to, Young's modulus, Poisson's ratio and bulk modulus of the reservoir rock; thus, after obtaining the rock property parameters, the reservoir stress balance equation can be constructed in combination with the pore pressure distribution data, and the process is shown in the following step S52.

[0127] S52. Construct the reservoir stress balance equation based on the pore pressure change according to the rock property parameters and the pore pressure distribution data; in specific implementation, the foregoing reservoir stress balance equation can be constructed by using the following formula (25).

[0128] (25) In the foregoing formula (25), denotes the total stress tensor of the reservoir matrix, denotes the Biot coefficient, denotes the bulk modulus of the reservoir rock, denotes the unit tensor, denotes the pore pressure distribution data, denotes the adsorption strain constant, denotes the adsorption volume of the unit mass medium, denotes the saturation load, b denotes the body force, and can be ignored, wherein, is obtained according to the Young's modulus and Poisson's ratio of the reservoir rock, and is calculated based on and the bulk modulus of the reservoir rock skeleton, Specifically, , wherein, denote the Young's modulus and Poisson's ratio of the reservoir rock, respectively, and , wherein, denotes the bulk modulus of the reservoir rock skeleton.

[0129] Thus, after constructing the reservoir stress balance equation by using the foregoing formula (25), the change value of the reservoir stress caused by the shale gas reservoir horizontal well production can be calculated based on the equation, and the process is shown in the following step S53.

[0130] S53. Solve the reservoir stress balance equation to obtain the change value of the reservoir stress caused by the shale gas reservoir horizontal well production; in this embodiment, the pore pressure distribution data obtained in the foregoing step S4 is substituted into the foregoing formula (25), so that the change value of the reservoir stress caused by the shale gas reservoir horizontal well production can be calculated, that is, the change value of the reservoir stress caused by the shale gas reservoir horizontal well production is calculated. ; and then, the induced stress field generated by the hydraulic fracture in the reservoir can be obtained, so as to combine the initial in-situ stress field of the reservoir matrix to determine the geostress field evolution data of the shale reservoir after the horizontal well production.

[0131] The induced stress field is obtained according to the following step S54.

[0132] S54. Obtain the induced stress field generated by the hydraulic fracture in the reservoir after the horizontal well production of the shale gas reservoir; in a specific implementation, considering the influence of the closure of the hydraulic fracture during the production of the horizontal well of the shale gas reservoir, for example, but not limited to, based on the trajectory and the fracture width of the hydraulic fracture in the first hydraulic fracture extension data, and by the relationship between the displacement and the induced stress in the displacement discontinuity method, the induced stress field generated by the hydraulic fracture in the reservoir after the production of the horizontal well of the shale gas reservoir is calculated; in this embodiment, according to the trajectory and the fracture width of the hydraulic fracture, and using the displacement discontinuity method to calculate the induced stress field, it is a common technical method for the induced stress field of the hydraulic fracture, and the process is mainly as follows: first, a mathematical model is established according to the displacement discontinuity method theory to describe the relationship between the fracture width and the induced stress of the hydraulic fracture, and then the fracture trajectory and the fracture width data are input into the mathematical model to calculate the induced stress field distribution caused by the hydraulic fracture in the reservoir; of course, the foregoing technology is a common calculation method for the induced stress field, and the calculation process will not be described here.

[0133] Thus, after obtaining the induced stress field, the initial in-situ stress field and the change value of the reservoir stress are combined to obtain the geostress field evolution data, and the process is shown in the following step S55.

[0134] S55. Perform stress superposition processing on the initial in-situ stress field, the change value of the reservoir stress and the induced stress field, so as to obtain the geostress field evolution data after stress superposition processing; in this embodiment, the initial in-situ stress field is the stress of the reservoir matrix when the horizontal well of the shale gas reservoir is not produced; based on this, the three stresses are superimposed to obtain the geostress field evolution data of the shale reservoir after the production of the horizontal well.

[0135] Thus, through the foregoing steps S51-S55, the geostress field of the shale reservoir after the production of the horizontal well can be predicted, and then, the geostress field evolution data is used as a boundary condition, and the initial in-situ stress field is used as a boundary condition to respectively perform the extension prediction of the hydraulic fracture in the fractured well, so as to obtain the extension data of the hydraulic fracture in the fractured well before and after the production of the horizontal well, and the process is shown in the following step S6.

[0136] S6. Respectively taking the in-situ stress field evolution data and the initial in-situ stress field of the shale reservoir as the boundary conditions, and using the horizontal well segmented multi-cluster fracturing fracture propagation model, the second hydraulic fracture extension data and the third hydraulic fracture extension data in the fractured well are obtained; in this embodiment, it is equivalent to recalculating the tangential stress component and the normal stress component, and the four influence coefficient matrices in the aforementioned formula (4) and formula (5) based on the in-situ stress field evolution data; then, the recalculated influence coefficients and the two stress components are substituted into the rock deformation constitutive equation, and combined with the fracturing fluid flow control equation, the fracture width (for easy distinction, named second fracture width) and the fluid pressure of the hydraulic fracture in the fractured well are recalculated; then, based on the fracture width of the hydraulic fracture in the fractured well and the aforementioned formula (16)-(18), the calculation of the fracture extension direction and the fracture length extension step of the hydraulic fracture is re-performed, and thus the fracture length (i.e. the second fracture length) of the hydraulic fracture in the fractured well is obtained; in this way, the fracture width and the fracture length of the hydraulic fracture in the fractured well can be used to form the second hydraulic fracture extension data; similarly, when the initial in-situ stress field is used as the boundary condition, the calculation process of the corresponding third hydraulic fracture extension data is also the same, which will not be described here.

[0137] Based on this, after obtaining the extension data of the hydraulic fracture in the fractured well before and after the horizontal well production, the interwell interference analysis can be performed based on the two, and the process is shown in the following step S7.

[0138] S7. The second hydraulic fracture extension data and the third hydraulic fracture extension data are used to obtain the interwell interference analysis result; in specific application, the second hydraulic fracture extension data includes the second fracture length and the second fracture width of the fractured well, and the third hydraulic fracture extension data includes the third fracture length and the third fracture width of the fractured well; in this way, the interference analysis can be performed according to the fracture width and fracture length data of the hydraulic fracture in the fractured well before and after the horizontal well production, and the process is shown in the following steps S71-S75.

[0139] S71. Based on the second fracture length and the second fracture width of the fractured well, the first average fracture length, the first average fracture width and the first fracture length variation coefficient are calculated; in this embodiment, for example, but not limited to, the first average fracture length, the second average fracture width and the first fracture length variation coefficient on both sides of the fractured well are calculated; wherein the first fracture length variation coefficient calculation formula is , wherein σ1 represents the first fracture length variation coefficient; μ1 represents the first average fracture length; σ2 represents the standard deviation of the second fracture length.

[0140] Similarly, for the horizontal well after production, the corresponding average fracture length, average fracture width and fracture length variation coefficient are also calculated, and the process is shown in the following step S72.

[0141] S72. According to the third fracture length and the third fracture width of the fractured well, the second average fracture length, the second average fracture width and the second fracture length variation coefficient are calculated; in this embodiment, the calculation process of the second fracture length variation coefficient is the same as the first fracture length variation coefficient, and will not be described here.

[0142] After obtaining the average fracture length, the average fracture width and the fracture length variation coefficient on both sides of the fractured well before and after the horizontal well production, the differences of the hydraulic fracture parameters considering and not considering the influence of the production well can be compared, and the interference degree of the horizontal well production of the shale gas reservoir on the fracturing of the adjacent well is quantitatively evaluated by using the change rate, and the process is shown in the following steps S73-S75.

[0143] S73. The fracture length change rate is obtained based on the first average fracture length and the second average fracture length.

[0144] S74. The fracture width change rate is obtained according to the first average fracture width and the second average fracture width, and the fracture length variation coefficient change rate is obtained based on the first fracture length variation coefficient and the second fracture length variation coefficient; thus, after obtaining the fracture length change rate, the fracture width change rate and the fracture length variation coefficient change rate, the aforementioned three change rates can be used to form the interwell interference analysis result, and the process is shown in the following step S75.

[0145] S75. The interwell interference analysis result is generated by using the fracture length change rate, the fracture width change rate and the fracture length variation coefficient change rate.

[0146] Thus, after obtaining the change rates of the differences of the hydraulic fracture parameters considering and not considering the influence of the production well through the aforementioned steps S71-S75, the interwell interference analysis result can be generated, and then the interwell interference analysis result can be visually displayed to assist the staff in arranging the horizontal well group and optimizing the horizontal well fracturing parameters; further, for example, the well group layout and the horizontal well fracturing parameter database can be set in advance in the interwell interference analysis end, wherein each well group layout and horizontal well fracturing parameter corresponds to a calibrated interwell interference analysis result (i.e. the change rate of the fracture length, the fracture width and the fracture length variation coefficient of the hydraulic fracture in the fractured well before and after the horizontal well production); then, according to the interwell interference analysis result obtained in the aforementioned step S7, data matching is performed in the well group layout and the horizontal well fracturing parameter database, so as to obtain the optimal well group layout information and the optimal horizontal well fracturing parameter corresponding to the interwell interference analysis result; finally, the optimal well group layout information and the optimal horizontal well fracturing parameter are visually displayed to provide guidance for the field horizontal well fracturing construction design and optimization.

[0147] Thus, through the method for analyzing the interference of horizontal well production in shale gas reservoirs on adjacent well fracturing described in detail in the aforementioned steps S1 to S7, the present invention takes into account the influence of natural fractures on hydraulic fracture expansion when predicting hydraulic fracture expansion, and fully considers the combined effects of initial in-situ stress distribution, induced stress field generated by hydraulic fractures, methane adsorption and desorption, and gas-liquid two-phase flow when quantifying the influence of pore pressure changes on reservoir stress evolution; therefore, compared with traditional technologies, the present invention improves the accuracy of the analysis of the interference of horizontal well production on adjacent well fracturing, and can provide guidance for the design and optimization of horizontal well fracturing construction.

[0148] In one possible design, the second aspect of this embodiment provides a simulation example of the analysis method described in the first aspect of the embodiment, and the data is shown below.

[0149] In this embodiment, the natural fracture surface density is 0.005, the average length of natural fractures is 12.0 m, the standard deviation of natural fracture length is 2.0 m, the average azimuth of natural fractures is 50° and 105°, and the deviation coefficient is 200. The natural fracture modeling in the reservoir is achieved by statistical methods. Figure 2 shown.

[0150] In this embodiment, when simulating the multi-cluster fracturing of a horizontal well, a refined short cluster design was considered, and four-stage fracturing was simulated with a stage length of about 120 m. The basic simulation parameters are shown in Table 1.

[0151] Table 1 shows the basic simulation parameters for staged multi-cluster fracturing of horizontal wells.

[0152] Table 1

[0153] In this way, the hydraulic fracture extension simulation can be performed based on the horizontal well segmented multi-cluster hydraulic fracturing fracture extension model constructed in the first aspect of the embodiment and the basic parameters in Table 1. The simulation results can be seen in Figure 3 As shown in Figure 3, the fracture extension trajectory and fracture width distribution results of multi-cluster fracturing in horizontal wells in shale reservoirs are obtained.

[0154] Then, based on Figure 3 The prediction results of fracture propagation in multi-cluster hydraulic fracturing of horizontal wells in the shale gas reservoir are used, and the pore pressure distribution in the shale reservoir under production conditions is predicted in combination with the horizontal well production seepage model. The production is carried out with a fixed bottom hole fluid pressure, and the geological parameters, engineering parameters, and production parameters required for pore pressure distribution prediction are simulated to obtain the basic simulation parameters of horizontal well production in shale gas reservoirs shown in Table 2 below.

[0155] Table 2 shows the basic simulation parameters for horizontal well production in shale gas reservoirs.

[0156] Table 2

[0157] Based on the data in the foregoing Table 2 and the horizontal well production percolation model in the first aspect of the embodiment, shale reservoir pore pressure distribution results are simulated and predicted, and the results are shown in Figs. 2 to 4. Figure 4 Figure 4 It can be known from Figs. 2 to 4 that the reservoir pore pressure drop region is mainly concentrated in the hydraulic fracture region and gradually spreads to the deep region of the hydraulic fracture, and the sweep range of the horizontal well production can be briefly analyzed through the range of the pressure drop region.

[0158] Then, based on the reservoir stress balance equation in the first aspect of the embodiment and the foregoing predicted pore pressure distribution, the change value of the reservoir stress caused by the horizontal well production of the shale gas reservoir is obtained, wherein the change value of the horizontal maximum principal stress is shown in Fig. 5, and the change value of the horizontal minimum principal stress is shown in Fig. 6. Figure 5 Figure 6 Further, considering the influence of the hydraulic fracture closure in the horizontal well production process of the shale gas reservoir, the induced stress field of the hydraulic fracture in the reservoir after the horizontal well production is calculated, wherein the induced stress along the horizontal minimum principal stress direction is shown in Fig. 7, and the induced stress along the horizontal maximum principal stress direction is shown in Fig. 8. Figure 7 Figure 8 Then, the geostress field evolution results of the shale reservoir after the horizontal well production can be calculated based on the stress superposition principle.

[0159] Finally, the stress field evolution results and the initial in-situ stress field are taken as the boundary conditions, and the horizontal well segmented multi-cluster fracturing fracture propagation model established in the first aspect of the embodiment is used to predict the extension of the hydraulic fracture in the fracturing well before and after the horizontal well production; wherein the extension trajectory and the fracture width distribution results of the hydraulic fracture in the fracturing well under the influence of the production well are shown in Figs. 9 to 11, and the extension trajectory and the fracture width distribution results of the hydraulic fracture in the fracturing well without the influence of the production well are shown in Figs. 12 to 14. Figure 9 Figure 10

[0160] In addition, the average fracture length, the average fracture width, the fracture length coefficient of variation and other parameters on both sides of the fracturing well are calculated based on the foregoing simulated hydraulic fracture extension data, and the specific reference is shown in Table 3.

[0161] Table 3 is a comparison table of the hydraulic fracture geometric parameter indexes with and without the influence of the production well.

[0162] Table 3

[0163] ​​​​​As can be seen from Table 3, the production well influences the overall length of the hydraulic fracture, and the average fracture length is reduced by 40.9% compared with the case without considering the influence of the production well, and the average fracture width is increased by about 45.4%; meanwhile, the fracture length variation coefficient shows that, in the case of considering the influence of the production well, the fracture length on the two sides of the horizontal well, i.e., the upper side of the fracturing wellbore far away from the production well and the lower side of the fracturing wellbore close to the production well, is obviously different, while the fracture length on the two sides of the fracturing wellbore is less different in the case without considering the influence of the production well; through comparison of the simulation results, the quantified evaluation of the interference of the shale gas reservoir horizontal well production on the fracturing of the adjacent well is achieved, which can provide guidance for the design and optimization of the fracturing construction of the horizontal well.

[0164] The third aspect of the embodiment provides a hardware device for implementing the analysis method of the interference of the shale gas reservoir horizontal well production on the fracturing of the adjacent well in the first aspect of the embodiment, and the hardware device comprises: a natural fracture modeling unit configured to establish a natural fracture model of the shale gas reservoir.

[0165] a hydraulic fracture prediction unit configured to construct a horizontal well staged multi-cluster fracturing fracture propagation model, and obtain first hydraulic fracture extension data in the horizontal well according to the natural fracture model and the horizontal well staged multi-cluster fracturing fracture propagation model.

[0166] a pore pressure prediction unit configured to establish a methane adsorption and desorption model in the production process of the shale gas reservoir, and construct a first gas-liquid two-phase flow control equation in the reservoir matrix of the shale gas reservoir according to the adsorption and desorption model.

[0167] The pore pressure prediction unit is further configured to establish a horizontal well production seepage flow model based on the first gas-liquid two-phase flow control equation and the first hydraulic fracture extension data, and predict pore pressure distribution data of the reservoir in the shale gas reservoir based on the horizontal well production seepage flow model.

[0168] a geostress field evolution unit configured to obtain an initial in-situ stress field of the shale reservoir, and determine geostress field evolution data of the shale reservoir after the production of the horizontal well according to the initial in-situ stress field and the pore pressure distribution data.

[0169] The hydraulic fracture prediction unit is further configured to take the geostress field evolution data of the shale reservoir and the initial in-situ stress field as boundary conditions respectively, and obtain second hydraulic fracture extension data and third hydraulic fracture extension data in the fracturing well by using the horizontal well staged multi-cluster fracturing fracture propagation model.

[0170] an interwell interference analysis unit configured to obtain an interwell interference analysis result by using the second hydraulic fracture extension data and the third hydraulic fracture extension data.

[0171] The working process, working details and technical effects of the device provided in the embodiment can be referred to the first aspect of the embodiment, and will not be described here again.

[0172] The fourth aspect of the embodiment provides another device for analyzing shale gas horizontal well production interference with adjacent well fracturing, taking the device as an electronic device, comprising: a memory, a processor and a transceiver connected in sequence and in communication, wherein the memory is configured to store a computer program, the transceiver is configured to transceive messages, and the processor is configured to read the computer program and execute the method for analyzing shale gas horizontal well production interference with adjacent well fracturing as described in the first aspect of the embodiment.

[0173] The working process, working details and technical effects of the electronic device provided by the embodiment can be referred to the first aspect of the embodiment, and will not be repeated here.

[0174] The fifth aspect of the embodiment provides a storage medium storing instructions of the method for analyzing shale gas horizontal well production interference with adjacent well fracturing as described in the first aspect of the embodiment, that is, the storage medium stores instructions, and when the instructions run on a computer, the method for analyzing shale gas horizontal well production interference with adjacent well fracturing as described in the first aspect of the embodiment is executed.

[0175] The storage medium refers to a carrier for storing data, which can include, but is not limited to, floppy disks, optical disks, hard disks, flash memories, USB flash disks and / or Memory Sticks, and the computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable devices.

[0176] The working process, working details and technical effects of the storage medium provided by the embodiment can be referred to the first aspect of the embodiment, and will not be repeated here.

[0177] The fifth aspect of the embodiment provides a computer program product containing instructions, which, when running on a computer, causes the computer to execute the method for analyzing shale gas horizontal well production interference with adjacent well fracturing as described in the first aspect of the embodiment, wherein the computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable devices.

[0178] The above detailed description of the specific embodiments has further described the purposes, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for analyzing the interference of horizontal well production in shale gas reservoirs with adjacent well fracturing, characterized in that: include: Establish a natural fracture model for shale gas reservoirs; Construct a fracture propagation model for staged multi-cluster hydraulic fracturing in horizontal wells, and obtain the first hydraulic fracture extension data in the horizontal well based on the natural fracture model and the fracture propagation model for staged multi-cluster hydraulic fracturing in horizontal wells; Establishing a methane adsorption and desorption model during shale gas reservoir production, and constructing a first gas-liquid two-phase flow control equation within the reservoir matrix of the shale gas reservoir based on the adsorption and desorption model; Based on the first gas-liquid two-phase flow governing equation and the first hydraulic fracture extension data, a horizontal well production seepage model is established. Based on the horizontal well production seepage model, the pore pressure distribution data of the reservoir in the shale gas reservoir is predicted. Obtaining an initial in-situ stress field of the shale reservoir, and determining, based on the initial in-situ stress field and the pore pressure distribution data, in-situ stress field evolution data of the shale reservoir after horizontal well production; The second and third hydraulic fracture extension data in the fractured wells were obtained by using the evolution data of the in-situ stress field of the shale reservoir and the initial in-situ stress field as boundary conditions and using the horizontal well multi-cluster fracturing fracture extension model. The inter-well interference analysis results are obtained using the second hydraulic fracture extension data and the third hydraulic fracture extension data.

2. The method according to claim 1, characterized in that Establish a natural fracture model for shale gas reservoirs, including: Obtaining geological parameters of the shale gas reservoir where the horizontal well is located, wherein the geological parameters include natural fracture surface density, reservoir area, natural fracture length, and natural fracture azimuth; constructing a natural fracture number model based on the natural fracture surface density and the reservoir area; constructing a natural fracture length model based on the length of the natural fracture; constructing a natural fracture azimuth model according to the azimuth of the natural fracture; The natural fracture model is composed of the natural fracture number model, the natural fracture length model and the natural fracture azimuth model.

3. The method according to claim 1, characterized in that Construct a fracture propagation model for staged multi-cluster fracturing in horizontal wells, including: The rock deformation constitutive equation under the combined action of in situ stress and fluid pressure in the hydraulic fracture stress field is constructed; Obtaining the construction and completion parameters of horizontal wells; Based on the construction parameters and completion parameters, the fracturing fluid flow control equation during the fracture propagation process of horizontal well fracturing is constructed; Using the rock deformation constitutive equation and the fracturing fluid flow control equation, a hydraulic fracture width and fluid pressure prediction model is constructed; Calculating a hydraulic fracture width matrix and a fluid pressure matrix within the hydraulic fracture based on the hydraulic fracture width and fluid pressure prediction model; Calculating the energy release rate at each hydraulic fracture tip according to the hydraulic fracture width matrix; constructing a hydraulic fracture trajectory prediction model and a fracture extension length model based on the natural fracture model, the fluid pressure matrix, and the energy release rate of each hydraulic fracture tip; The horizontal well segmented multi-cluster hydraulic fracturing fracture propagation model is composed of the fracture propagation length model, the trajectory prediction model and the hydraulic fracture width and fluid pressure prediction model.

4. The method according to claim 3, characterized in that The rock deformation constitutive equation of the hydraulic fracture stress field under the combined action of in-situ stress and fluid pressure is constructed, including: Obtaining the normal stress component and the tangential stress component acting on the hydraulic fracture, as well as a first influence coefficient matrix between the normal and the normal directions based on the fracture height correction, a second influence coefficient matrix between the tangential and the tangential directions based on the fracture height correction, a third influence coefficient matrix between the normal and the tangential directions based on the fracture height correction, and a fourth influence coefficient matrix between the tangential and the normal directions based on the fracture height correction between the hydraulic fractures; Calculating a comprehensive ground stress matrix acting on the hydraulic fracture based on the normal stress component, the tangential stress component, the third influence coefficient matrix, and the second influence coefficient matrix; Calculating a comprehensive influence coefficient matrix based on the first influence coefficient matrix, the second influence coefficient matrix, the third influence coefficient matrix, and the fourth influence coefficient matrix; The rock deformation constitutive equation based on the hydraulic fracture width and the fluid pressure in the hydraulic fracture is constructed by using the comprehensive geostress matrix and the comprehensive influence coefficient matrix.

5. The method according to claim 3, characterized in that Based on the construction parameters and completion parameters, the fracturing fluid flow control equation during the horizontal well fracturing crack expansion process is constructed, including: Obtaining the fracturing fluid flow coefficient matrix; Based on the operation parameters and completion parameters, the horizontal wellbore friction and perforation hole friction of each perforation cluster in the horizontal well are calculated; Calculating the fracturing fluid displacement of each perforation cluster based on the horizontal wellbore friction and perforation hole friction of each perforation cluster; The fracturing fluid flow coefficient matrix and the fracturing fluid displacement of each perforation cluster are used to construct the fracturing fluid flow control equation based on the hydraulic fracture width and the fluid pressure in the hydraulic fracture.

6. The method according to claim 1, characterized in that Based on the adsorption-desorption model, the first gas-liquid two-phase flow control equation in the reservoir matrix of the shale gas reservoir is constructed, including: Obtaining the property parameters of methane in shale gas reservoirs; Based on the attribute parameters, a gas motion equation of methane is constructed; Based on the gas motion equation and the adsorption-desorption model, the first gas-liquid two-phase flow control equation is constructed.

7. The method according to claim 1, characterized in that Establish a methane adsorption and desorption model during shale gas reservoir production, including: Obtain the gas constant of methane, as well as the saturation load and component adsorption enthalpy change of methane in shale gas reservoirs; The adsorption-desorption model is constructed according to the gas constant, the saturation load and the adsorption enthalpy change of the component and in accordance with the following formula; Where, represents the adsorption-desorption model, represents the saturation load, are constants, represents the adsorption enthalpy change of the component, represents the gas constant, Indicates temperature, represents the heterogeneity constant, Indicates gas pressure.

8. The method according to claim 1, characterized in that Based on the first gas-liquid two-phase flow governing equation and the first hydraulic fracture extension data, a horizontal well production seepage model is established, including: Obtain reservoir matrix permeability; calculating an exchange coefficient between the hydraulic fracture and the reservoir matrix based on the first hydraulic fracture extension data and the reservoir matrix permeability; constructing a second gas-liquid two-phase flow control equation in the hydraulic fracture based on the exchange coefficient; The finite volume method is used to discretize the first gas-liquid two-phase flow control equation and the second gas-liquid two-phase flow control equation to obtain the horizontal well production seepage model.

9. The method according to claim 1, characterized in that Determining the geostress field evolution data of the shale reservoir after horizontal well production based on the initial in-situ stress field and the pore pressure distribution data includes: Obtain rock property parameters of shale reservoirs; Constructing a reservoir stress balance equation based on pore pressure changes according to the rock property parameters and the pore pressure distribution data; Solving the reservoir stress balance equation to obtain a change in reservoir stress caused by horizontal well production in a shale gas reservoir; Obtain the induced stress field generated by hydraulic fractures in the reservoir after horizontal well production in shale gas reservoirs; Stress superposition processing is performed on the initial in-situ stress field, the change value of the reservoir stress and the induced stress field, so as to obtain the in-situ stress field evolution data after the stress superposition processing.

10. The method according to claim 1, characterized in that The second hydraulic fracture extension data includes: a second fracture length and a second fracture width of the fractured well, and the third hydraulic fracture extension data includes a third fracture length and a third fracture width of the fractured well; The second hydraulic fracture extension data and the third hydraulic fracture extension data are used to obtain the inter-well interference analysis results, including: Calculating a first average fracture length, a first average fracture width, and a first fracture length variation coefficient based on a second fracture length and a second fracture width of the fractured well; Calculating the second average fracture length, the second average fracture width, and the second fracture length variation coefficient according to the third fracture length and the third fracture width of the fracturing well; Based on the first average seam length and the second average seam length, a seam length change rate is obtained; Obtaining a rate of change of the seam width based on the first average seam width and the second average seam width, and obtaining a rate of change of the coefficient of variation of the seam length based on the first coefficient of variation of the seam length and the second coefficient of variation of the seam length; The inter-well interference analysis result is generated by using the fracture length change rate, the fracture width change rate and the fracture length variation coefficient change rate.

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