Compact low-permeability reservoir water injection development complex fracture network geological modeling method and device

Abstract

The invention discloses a compact low-permeability reservoir water injection development complex fracture network geological modeling method and device, and the method comprises the steps: building a first geological model for a natural fracture of a target region, so as to determine the four-dimensional ground stress distribution characteristics of the target region in a water injection development process, and determining a first distribution characteristic of the hydraulic fracturing crack generated in the hydraulic fracturing process. And constructing a second geologic model of a first coupling fracture network of the natural fractures and the hydraulic fractures of the target area according to the first distribution features. Obtaining influence parameters of water injection induced cracks; and inputting the influence parameters and the four-dimensional ground stress distribution characteristics into a second geologic model to output second distribution characteristics of the water injection induced cracks in the first coupling crack network. And performing modeling according to the second distribution characteristics to construct a third geologic model of a second coupling fracture network of the natural fracture, the hydraulic fracturing fracture and the water injection induced fracture. According to the scheme, the distribution rule of the coupling seam network system in the water injection development process can be well predicted.

Description

Technical Field

[0001] The present application relates to the technical field of oil and gas geology and oil and gas field development geology, and specifically to a method, device and storage medium for geological modeling of complex fracture networks in water injection development of dense low-permeability reservoirs. Background Art

[0002] Tight low-permeability reservoirs have poor physical properties, strong heterogeneity, and widespread natural fractures. They usually need to be transformed by fracturing to generate hydraulic fractures to improve the permeability of the reservoirs, and long-term water injection development. Due to long-term water injection, the reservoir stress has changed, causing dynamic changes in natural fractures and hydraulic fractures, resulting in water injection-induced fractures, aggravating the heterogeneity of the reservoir, affecting the development effect of the oil field, and causing a large amount of residual oil enrichment. At present, reservoir fracture modeling is mostly focused on single-genetic type fractures, and the fracture models of different genetic types are relatively isolated. In the modeling process, there is a lack of consideration of the coupling relationship between fractures of different genesis and an effective description of their dynamic evolution process. In addition, long-term water injection development leads to dynamic changes in the fracture network system of tight reservoirs, that is, the formation of water injection-induced fractures with directional and high permeability characteristics. However, there is currently no fracture network system modeling method for coupled water injection-induced fractures, which often fails to meet actual production needs. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a method, device and storage medium for geological modeling of complex fracture networks in dense low-permeability reservoir water injection development, so as to solve the problem that the prior art lacks consideration of the coupling relationship between fractures of different causes and effective description of their dynamic evolution process, and cannot meet actual production needs.

[0004] In order to achieve the above-mentioned object, the first aspect of the present application provides a method for geological modeling of complex fracture networks in water injection development of dense low permeability reservoirs, the method comprising:

[0005] Establishing a first geological model of natural fractures in the target area;

[0006] Determine the four-dimensional geostress distribution characteristics of the target area during water injection development based on the first geological model;

[0007] Determining first distribution characteristics of hydraulic fractures generated in the target area during the hydraulic fracturing process based on the first geological model;

[0008] Modeling is performed according to the first distribution characteristics to construct a second geological model of a first coupled fracture network of natural fractures and hydraulic fractures in the target area;

[0009] Obtain the influencing parameters of water injection-induced fractures in the target area;

[0010] Inputting the influencing parameters and the four-dimensional ground stress distribution characteristics into the second geological model, so as to output the second distribution characteristics of the water injection-induced fractures in the target area in the first coupled fracture network through the second geological model;

[0011] Modeling is performed based on the second distribution characteristics to construct a third geological model of a second coupled fracture network of natural fractures, hydraulic fractures, and water injection induced fractures in the target area.

[0012] In an embodiment of the present application, establishing a first geological model of natural fractures for a target area includes: obtaining a first parameter of the natural fractures and the development intensity of fractures in a single well; determining the planar distribution law of the natural fractures; using the planar distribution law as a spatial constraint trend, and constructing a development intensity constraint body corresponding to the natural fractures according to the development intensity of fractures in a single well; constructing a first discrete network model of the natural fractures using the first parameter as a constraint; and fusing the development intensity constraint body and the first discrete network model to obtain a first geological model of the natural fractures for the target area.

[0013] In an embodiment of the present application, determining the four-dimensional geostress distribution characteristics of the target area during the water injection development process based on the first geological model includes: constructing a reservoir geomechanical model of the target area based on the first geological model, and determining the boundary conditions of the target area; predicting the three-dimensional geostress field distribution characteristics in the reservoir of the target area based on the reservoir geomechanical model and boundary conditions based on the finite element numerical simulation method; determining the four-dimensional geostress distribution characteristics of the target area during the water injection development process based on the three-dimensional geostress field distribution characteristics based on the reservoir numerical simulation method.

[0014] In an embodiment of the present application, determining the first distribution characteristics of hydraulic fractures generated in the target area during the hydraulic fracturing process based on the first geological model includes: determining whether there are natural fractures in the formation of the target area; in the case where there are natural fractures in the formation of the target area, determining the first formation initiation conditions for hydraulic fractures generated in the target area during the hydraulic fracturing process; in the case where there are natural fractures in the formation of the target area, determining the first distribution characteristics of the hydraulic fractures generated in the target area during the hydraulic fracturing process according to the first formation initiation conditions; in the case where there are no natural fractures in the formation of the target area, determining the second formation initiation conditions for hydraulic fractures generated in the target area during the hydraulic fracturing process; and determining the first distribution characteristics of the hydraulic fractures generated in the target area during the hydraulic fracturing process according to the second formation initiation conditions.

[0015] In the embodiment of the present application, the functional expression of the first formation fracturing condition is shown in the following formulas (1) and (2):

[0016] P p >P f (1)

[0017] Pf =3σ h -σ H +σ t -P p (2)

[0018] Among them, P p It refers to the formation fracture pressure in the target area, P f refers to the formation fracture pressure in the target area, σ h refers to the current horizontal minimum principal stress of the reservoir in the target area, σ H refers to the current horizontal maximum principal stress of the reservoir in the target area, σ t It refers to the tensile strength of the reservoir rock in the target area, P p It refers to the formation pore fluid pressure in the target area.

[0019] In the embodiment of the present application, the functional expression of the second formation fracturing condition is shown in the following formulas (3) and (4):

[0020] P p >P i (3)

[0021]

[0022] P i It refers to the opening pressure of natural fractures in the target area, P o The overburden pressure in the target area, v refers to the Poisson's ratio in the target area, θ refers to the fracture dip in the target area, and β refers to the angle between the maximum principal stress direction and the fracture strike in the target area.

[0023] In an embodiment of the present application, modeling is performed according to the first distribution feature to construct a second geological model of a first coupled fracture network of natural fractures and hydraulic fractures in a target area, including: constructing a first mathematical model according to the first distribution feature; simulating based on the first mathematical model to obtain a second parameter of the hydraulic fractures under the influence of natural fractures; constructing a second discrete network model corresponding to the hydraulic fractures under the influence of natural fractures according to the second parameter based on a deterministic modeling method; integrating the first geological model and the second discrete network model in time and space to construct a second geological model of a first coupled fracture network of natural fractures and hydraulic fractures in the target area.

[0024] In an embodiment of the present application, modeling is performed according to the second distribution characteristics to construct a third geological model of a second coupled fracture network of natural fractures, hydraulic fractures and water injection induced fractures in the target area, including: constructing a second mathematical model according to the second distribution characteristics; simulating based on the second mathematical model to obtain a third parameter of water injection induced fractures under the influence of natural fractures and hydraulic fractures; constructing a third discrete network model corresponding to water injection induced fractures under the influence of natural fractures and hydraulic fractures according to the third parameter based on a deterministic modeling method; integrating the second geological model and the third discrete network model in time and space to construct a third geological model of a second coupled fracture network of natural fractures, hydraulic fractures and water injection induced fractures in the target area.

[0025] The second aspect of the present application provides a geological modeling device for complex fracture networks in dense low-permeability reservoir water injection development, comprising:

[0026] a memory configured to store instructions;

[0027] The processor is configured to call instructions from the memory and implement the complex fracture network geological modeling method for water injection development of dense low permeability reservoirs according to the above-mentioned instructions when executing the instructions.

[0028] A third aspect of the present application provides a machine-readable storage medium having instructions stored thereon, the instructions being used to enable a machine to execute the above-mentioned complex fracture network geological modeling method for water injection development of dense low-permeability reservoirs.

[0029] Through the above technical scheme, by establishing a first geological model for natural fractures in the target area; determining the four-dimensional geostress distribution characteristics of the target area during water injection development based on the first geological model; determining the first distribution characteristics of hydraulic fractures generated in the target area during hydraulic fracturing based on the first geological model; modeling based on the first distribution characteristics, constructing a second geological model of the first coupled fracture network of natural fractures and hydraulic fractures in the target area; obtaining the influencing parameters of water injection induced fractures in the target area; inputting the influencing parameters and the four-dimensional geostress distribution characteristics into the second geological model, so as to output the second distribution characteristics of water injection induced fractures in the target area in the first coupled fracture network through the second geological model; modeling based on the second distribution characteristics, so as to construct a third geological model of the second coupled fracture network of natural fractures, hydraulic fractures and water injection induced fractures in the target area. The above scheme can better predict the distribution law of the fracture network system of natural fractures, hydraulic fractures and water injection induced fractures coupled during water injection development, and can provide geological basis for adjusting the development mode of dense low permeability reservoirs in the middle and late stages and tapping the potential of remaining oil, thereby improving the recovery rate of dense low permeability reservoirs.

[0030] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the accompanying drawings:

[0032] Figure 1 A schematic diagram of a flow chart of a method for geological modeling of a complex fracture network for water injection development of a dense low-permeability reservoir according to an embodiment of the present application is shown;

[0033] Figure 2 A three-dimensional geological model for constructing a first coupled fracture network of natural fractures and hydraulic fractures according to an embodiment of the present application is schematically shown;

[0034] Figure 3 A schematic diagram shows a three-dimensional geological model of a second coupled fracture network of natural fractures, hydraulic fractures, and water injection induced fractures constructed according to an embodiment of the present application;

[0035] Figure 4 A schematic diagram of a three-dimensional geological model of a second coupled fracture network according to an embodiment of the present application is schematically shown;

[0036] Figure 5 A structural block diagram of a complex fracture network geological modeling device for water injection development of a dense low-permeability reservoir according to an embodiment of the present application is schematically shown;

[0037] Figure 6 The schematic diagram shows a structure of a computer device according to an embodiment of the present application. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the specific implementation methods described herein are only used to illustrate and explain the embodiments of the present application, and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0039] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0040] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0041] Figure 1 The following schematically shows a flow chart of a method for complex fracture network geological modeling for water injection development of a dense low permeability reservoir according to an embodiment of the present application. Figure 1 As shown, an embodiment of the present application provides a method for geological modeling of complex fracture networks in water injection development of dense low permeability reservoirs, and the method may include the following steps.

[0042] S102, establishing a first geological model of natural fractures in the target area.

[0043] It can be understood that the target area refers to a geological area with dense low permeability reservoirs and water injection development. Dense low permeability reservoirs have poor physical properties, strong heterogeneity, and generally develop natural fractures. They usually need to be transformed by fracturing to generate hydraulic fractures to improve the permeability of the reservoir and undergo long-term water injection development. The first geological model refers to a three-dimensional geological model of natural fractures in the target area.

[0044] In an embodiment of the present application, establishing a first geological model of natural fractures for a target area includes: obtaining a first parameter of the natural fractures and the development intensity of fractures in a single well; determining the planar distribution law of the natural fractures; using the planar distribution law as a spatial constraint trend, and constructing a development intensity constraint body corresponding to the natural fractures according to the development intensity of fractures in a single well; constructing a first discrete network model of the natural fractures using the first parameter as a constraint; and fusing the development intensity constraint body and the first discrete network model to obtain a first geological model of the natural fractures for the target area.

[0045] Specifically, the intensity of fracture development in a single well is an indicator that reflects the degree of fracture development in a single well. It involves factors such as the number, length, width and density of fractures, which together determine the degree of fracture development in rocks. The intensity of fracture development in a single well can specifically be the longitudinal intensity of fracture development in a single well. The first parameter refers to the parameter characteristics of natural fractures, which can be obtained through seismic, well logging, surface outcrop and other data. The plane distribution law of natural fractures is mainly affected by factors such as tectonic stress, rock properties, and rock layer thickness, resulting in a certain regularity in the distribution of natural fractures on the plane, which can be linear, mesh, strip, etc. Specifically, the plane distribution law of natural fractures can be revealed by seismic pre-stack and post-stack attribute fracture prediction methods and reservoir geomechanics methods. Further, the plane distribution law of natural fractures is used as a spatial constraint trend, and the development intensity constraint body of natural fractures in the target area is established according to the deterministic modeling method based on the intensity of fracture development in a single well. The development intensity constraint body refers to a three-dimensional geological model of natural fractures constrained by the restricted position, the intensity of fracture development in a single well, etc. The development intensity constraint body has certain information and is large in scale. In addition, the first discrete network model of natural fractures can be constructed by using the random modeling method based on the first parameter of the natural fractures as a constraint. It can be understood that the discrete network model is a quantitative model used to study the spatial distribution, morphology, connectivity and other characteristics of fractures in rocks, that is, to simplify the complex fracture system inside the rock into a series of calculable discrete units (i.e. fracture slices) to construct a spatial model that can reflect the actual geological structure. The first discrete network model is small in scale and does not have a certain spatial position and parameter information. Furthermore, the two natural fracture models of different planning, the development intensity constraint body and the first discrete network model, can be merged to form the first geological model of natural fractures in the target area.

[0046] S104, determining four-dimensional geostress distribution characteristics of the target area during water injection development based on the first geological model.

[0047] It can be understood that four-dimensional geostress refers to the description of stress by adding a time dimension on the basis of the three-dimensional spatial stress state. The four-dimensional geostress distribution characteristics combine the two dimensions of space and time to describe the stress characteristics in underground reservoirs or formations. It can reflect the changes in the stress state of reservoirs or formations with spatial position and over time during underground engineering activities, such as the water injection development of oil and gas production. During the process of oil and gas production by water injection development, the pressure of the reservoir will drop rapidly, causing the original three-dimensional geostress of the reservoir to change continuously over time, so the dynamic four-dimensional geostress distribution characteristics can be obtained.

[0048] In an embodiment of the present application, determining the four-dimensional geostress distribution characteristics of the target area during the water injection development process based on the first geological model includes: constructing a reservoir geomechanical model of the target area based on the first geological model, and determining the boundary conditions of the target area; predicting the three-dimensional geostress field distribution characteristics in the reservoir of the target area based on the reservoir geomechanical model and boundary conditions based on the finite element numerical simulation method; determining the four-dimensional geostress distribution characteristics of the target area during the water injection development process based on the three-dimensional geostress field distribution characteristics based on the reservoir numerical simulation method.

[0049] It can be understood that the reservoir geomechanics model is a model that quantitatively describes and simulates the mechanical properties, stress state, deformation characteristics and fluid flow laws of reservoir rocks by comprehensively applying multidisciplinary knowledge such as geology, rock mechanics, and fluid mechanics. Specifically, on the basis of the first geological model, the reservoir geomechanics model can be constructed in combination with rock mechanics experiments and acoustic logging data, and the boundary conditions of the target area can be determined. Boundary conditions include but are not limited to surface loads, the size and direction of tectonic stress fields, etc. The finite element numerical simulation method is used to predict the three-dimensional geostress field distribution characteristics in the reservoir of the target area based on the reservoir geomechanics model and boundary conditions. The three-dimensional geostress field can clarify the law of change of geostress with depth and orientation, identify stress concentration areas and stress release areas, and provide a data basis for subsequent fracture expansion analysis. On this basis, the reservoir numerical simulation method is used to clarify the four-dimensional geostress distribution characteristics of the reservoir in the target area during water injection development based on the three-dimensional geostress field distribution characteristics and actual production dynamic data.

[0050] S106: Determine first distribution characteristics of hydraulic fractures generated in the target area during the hydraulic fracturing process based on the first geological model.

[0051] It can be understood that the first distribution feature refers to the distribution feature of hydraulic fractures in the target area during the hydraulic fracturing process. The first distribution feature includes but is not limited to fracture type, fracture width and length, fracture height, fracture density and distribution, and fracture mechanical characteristics. Specifically, based on the fracture mechanics theory, the mechanical mechanism of fracture expansion during hydraulic fracturing can be analyzed, including fracture initiation, extension, and turning behaviors. On this basis, through finite element numerical simulation experiments, the hydraulic fracture expansion mode under the influence of different injection pressures, fluid properties, rock mechanical properties, and natural fractures can be clarified, and the fracture morphology can be recorded. Furthermore, the simulation results of the simulation experiment are calibrated with actual microseismic monitoring data to determine the first distribution feature of hydraulic fractures that conform to the actual situation of the target area.

[0052] In an embodiment of the present application, determining the first distribution characteristics of hydraulic fractures generated in the target area during the hydraulic fracturing process based on the first geological model includes: determining whether there are natural fractures in the formation of the target area; in the case where there are natural fractures in the formation of the target area, determining the first formation initiation conditions for hydraulic fractures generated in the target area during the hydraulic fracturing process; in the case where there are natural fractures in the formation of the target area, determining the first distribution characteristics of the hydraulic fractures generated in the target area during the hydraulic fracturing process according to the first formation initiation conditions; in the case where there are no natural fractures in the formation of the target area, determining the second formation initiation conditions for hydraulic fractures generated in the target area during the hydraulic fracturing process; and determining the first distribution characteristics of the hydraulic fractures generated in the target area during the hydraulic fracturing process according to the second formation initiation conditions.

[0053] Specifically, based on the fracture mechanics theory, the behavior of fracture initiation during the hydraulic fracturing process is analyzed. First, it is determined whether there are natural fractures in the formation of the target area. If there are natural fractures, the first formation initiation condition for hydraulic fractures in the target area during the hydraulic fracturing process can be determined. If there are no natural fractures, the second formation initiation condition for hydraulic fractures in the target area during the hydraulic fracturing process can be determined. It can be understood that the first formation initiation condition and the second formation initiation condition are relative, and are the formation initiation conditions when there are natural fractures and when there are no natural fractures in the target area, respectively. Specifically, the first formation initiation condition can be used to determine whether fractures have occurred based on the formation initiation pressure and the formation fracture pressure. The second formation initiation condition can be used to determine whether fractures have occurred based on the formation initiation pressure and the opening pressure of the natural fracture.

[0054] Specifically, in the embodiment of the present application, when there are no natural fractures in the formation, the first formation fracturing condition is: when the formation fracturing pressure is greater than the formation fracture pressure, hydraulic fractures can be generated in the target area during the hydraulic fracturing process. The functional expression of the first formation fracturing condition is shown in the following formulas (1) and (2):

[0055] P p >P f (1)

[0056] P f =3σ h -σ H +σ t -P p (2)

[0057] Among them, P p It refers to the formation fracture pressure in the target area, P f refers to the formation fracture pressure in the target area, σ his the current horizontal minimum principal stress of the reservoir in the target area, σ H refers to the current horizontal maximum principal stress of the reservoir in the target area, σ t It refers to the tensile strength of the reservoir rock in the target area, P p It refers to the formation pore fluid pressure in the target area.

[0058] In the embodiment of the present application, when there are natural fractures in the formation, the second formation fracturing condition is: when the formation fracturing pressure is greater than the natural fracture opening pressure, hydraulic fractures can be generated in the target area during the hydraulic fracturing process. The functional expression of the second formation fracturing condition is shown in the following formulas (3) and (4):

[0059] P p >P i (3)

[0060]

[0061] Among them, P p refers to the formation fracture pressure in the target area, P i It refers to the opening pressure of natural fractures in the target area, P o The overburden pressure in the target area, v refers to the Poisson's ratio in the target area, θ refers to the fracture dip in the target area, and β refers to the angle between the maximum principal stress direction and the fracture strike in the target area.

[0062] S108, modeling is performed according to the first distribution characteristics to construct a second geological model of a first coupled fracture network of natural fractures and hydraulic fractures in the target area.

[0063] It can be understood that the coupled fracture network refers to a network system formed by the coupling of artificial fractures and natural fractures formed by artificial fracturing in a dense low-permeability reservoir, or a network system of artificial fractures formed by fracturing. The first coupled fracture network refers to a network system formed by the coupling of natural fractures and hydraulic fractures in the target area. The second geological model refers to a three-dimensional geological model of the first coupled fracture network in the target area. It can be understood that the first distribution feature refers to the distribution feature of hydraulic fractures in the target area during the hydraulic fracturing process. Therefore, modeling can be performed based on the first distribution feature to construct a second geological model of the first coupled fracture network of natural fractures and hydraulic fractures in the target area.

[0064] In an embodiment of the present application, modeling is performed according to the first distribution feature to construct a second geological model of a first coupled fracture network of natural fractures and hydraulic fractures in a target area, including: constructing a first mathematical model according to the first distribution feature; simulating based on the first mathematical model to obtain a second parameter of the hydraulic fractures under the influence of natural fractures; constructing a second discrete network model corresponding to the hydraulic fractures under the influence of natural fractures according to the second parameter based on a deterministic modeling method; integrating the first geological model and the second discrete network model in time and space to construct a second geological model of a first coupled fracture network of natural fractures and hydraulic fractures in the target area.

[0065] It can be understood that the second parameter refers to the parameter information of the hydraulic fracture under the influence of the natural fracture, including but not limited to the length, width, direction, spatial position, and intersection relationship between the hydraulic fracture and the natural fracture. Figure 2 Based on the fracture mechanics theory, the mechanical mechanism of fracture expansion during hydraulic fracturing is analyzed, including fracture initiation, extension, and diversion. On this basis, the first geological model obtained based on the above scheme, that is, the three-dimensional geological fine model of natural fractures, can be used to clarify the hydraulic fracture expansion mode under the influence of different injection pressures, fluid properties, rock mechanical properties, and natural fractures through finite element numerical simulation experiments, and record the fracture morphology. Further, the simulation results of the simulation experiment are calibrated with actual microseismic monitoring data to determine the first distribution characteristics of hydraulic fractures that meet the actual conditions of the target area. Further, the deterministic modeling method is used to construct a second discrete network model corresponding to hydraulic fractures under the influence of natural fractures according to the second parameter. The second discrete network model is relative to the first discrete network model, and the second discrete network model refers to the discrete network model corresponding to hydraulic fractures under the influence of natural fractures. The first geological model and the second discrete network model are integrated in time and space to construct a second geological model of the first coupled fracture network of natural fractures and hydraulic fractures in the target area. The second geological model can reflect a complex fracture network system with three-dimensional dynamics.

[0066] In one embodiment, the functional expression of the first mathematical model is shown in the following formulas (5), (6) and (7). Specifically, through the plane strain problem of the reservoir rock, and assuming that the hydraulic fractures only expand in the reservoir, the width of the hydraulic fractures in the simulation satisfies the following formula (5):

[0067]

[0068] Among them, W HF refers to the hydraulic fracture width, E refers to the reservoir Young's modulus, P frac It refers to the fluid pressure in the main fracture of the hydraulic fracture. refers to the main fracture height, v refers to the Poisson's ratio of the target area, σ H It refers to the current horizontal maximum principal stress of the reservoir in the target area.

[0069] The main crack width and crack height satisfy the ellipse formula. Combined with the rock fracture mechanics theory, it can be seen that when the stress intensity factor at the crack tip reaches the fracture toughness of the crack, the crack begins to expand. The main crack height of the hydraulic fracture is expressed according to the following formula (6):

[0070]

[0071] Among them, H HF refers to the main crack height, K refers to the fracture toughness of the crack, P frac is the fluid pressure in the main fracture of the fracture, σ H It refers to the current horizontal maximum principal stress of the reservoir in the target area.

[0072]

[0073] Among them, L HF refers to the length of the hydraulic fracture, G refers to the shear modulus of the reservoir rock, q refers to the single-wing discharge flow rate of the fracturing fluid, λ refers to the viscosity of the fracturing fluid, t refers to the injection time of the fracturing fluid, and v refers to the Poisson's ratio of the target area.

[0074] S110, obtaining influencing parameters of water injection-induced fractures in the target area.

[0075] Specifically, the influencing parameters of water injection-induced fractures include but are not limited to production dynamic data, water absorption profile, formation pressure monitoring and other data.

[0076] S112, inputting the influencing parameters and the four-dimensional geostress distribution characteristics into the second geological model, so as to output the second distribution characteristics of the water injection induced fractures in the target area in the first coupled fracture network through the second geological model.

[0077] Specifically, according to the formation mechanism of water injection-induced fractures in the reservoir, the production dynamic data of the whole area, water absorption profile, formation pressure monitoring and other data can be integrated as the input of the second geological model. Then, according to the four-dimensional ground stress distribution characteristics of the target area, the numerical simulation method is used to determine the opening, expansion and extension characteristics of fractures of different genesis types, and to clarify the second distribution characteristics of water injection-induced fractures under the first coupled fracture network system of natural fractures and hydraulic fractures. The second distribution characteristics include dynamic distribution characteristics and spatial distribution characteristics.

[0078] In an embodiment of the present application, modeling is performed according to the second distribution characteristics to construct a third geological model of a second coupled fracture network of natural fractures, hydraulic fractures and water injection induced fractures in the target area, including: constructing a second mathematical model according to the second distribution characteristics; simulating based on the second mathematical model to obtain a third parameter of water injection induced fractures under the influence of natural fractures and hydraulic fractures; constructing a third discrete network model corresponding to water injection induced fractures under the influence of natural fractures and hydraulic fractures according to the third parameter based on a deterministic modeling method; integrating the second geological model and the third discrete network model in time and space to construct a third geological model of a second coupled fracture network of natural fractures, hydraulic fractures and water injection induced fractures in the target area.

[0079] It can be understood that the third parameter refers to the parameter information of water injection induced fractures under the influence of natural fractures and hydraulic fractures, including but not limited to the length, width, direction, spatial position, and intersection relationship between water injection induced fractures and natural fractures and hydraulic fractures. The third discrete network model refers to the discrete network model corresponding to water injection induced fractures under the influence of natural fractures and hydraulic fractures. Specifically, the second mathematical model can be the length, height and opening distribution function of water injection induced fractures, and its function expression is shown in the following formula (8):

[0080] WFIF i =f(E i , Q i , v i , t i ) (8)

[0081] Among them, WFIF i It refers to the distribution function of the width, length or opening parameters of water injection-induced fractures at different water injection stages in the reservoir. i , Q i and v i They refer to the rock mechanical parameter characteristics of the reservoir at different water injection stages, t i It refers to the injection time of different water injection stages of the reservoir, and i refers to the i-th time period of reservoir water injection development.

[0082] S114, modeling is performed according to the second distribution characteristics to construct a third geological model of a second coupled fracture network of natural fractures, hydraulic fractures, and water injection induced fractures in the target area.

[0083] Specifically, refer to Figure 3According to the genetic mechanism of water injection-induced fractures in the reservoir, the production dynamic data, water absorption profile, formation pressure monitoring and other data of the whole area can be integrated as the input of the second geological model. Then, according to the four-dimensional geostress distribution characteristics of the target area, the numerical simulation method is used to determine the opening and extension characteristics of fractures of different genetic types, and the second distribution characteristics of water injection-induced fractures under the first coupled fracture network system of natural fractures and hydraulic fractures are clarified. According to the second distribution characteristics, a second mathematical model is constructed, and simulation is performed based on the second mathematical model to obtain the third parameter of water injection-induced fractures under the influence of natural fractures and hydraulic fractures. Based on the deterministic modeling method, a third discrete network model corresponding to water injection-induced fractures under the influence of natural fractures and hydraulic fractures is constructed according to the third parameter. The second geological model and the third discrete network model are integrated in time and space to construct the third geological model of the second coupled fracture network of natural fractures, hydraulic fractures and water injection-induced fractures in the target area. Furthermore, through methods such as reservoir numerical simulation history fitting and production data playback, the established complex second coupled fracture network is corrected and optimized to ensure the accuracy and practicality of the third geological model, providing a geological model for adjusting the development plan of tight and low-permeability oil and gas and tapping the potential of remaining oil.

[0084] In a specific embodiment, Figure 4 As shown, taking a tight oil reservoir of the Yanchang Formation in a certain basin as an example, a three-dimensional geological model of a complex fracture network system of natural fractures, hydraulic fractures and water injection induced fractures coupled during its water injection development is established. The embodiment shows that the method provided by the present application solves the problem of modeling a complex fracture network system of natural fractures, hydraulic fractures and water injection induced fractures coupled in tight low permeability reservoirs, and fully considers the interaction and dynamic changes of natural fractures, hydraulic fractures and water injection induced fractures during water injection development. The modeling results show that the constructed model is highly reliable, can more accurately describe the known hydraulic fractures and water injection induced fracture characteristics, and more comprehensively reflect the distribution law of the complex fracture network system of the tight oil reservoir, providing a three-dimensional geological model of the complex fracture network system that conforms to reality for the adjustment of the reservoir development plan and the potential of remaining oil, which has an important geological basis for improving the recovery rate of the tight oil reservoir.

[0085] Through the above technical scheme, by establishing a first geological model for natural fractures in the target area; determining the four-dimensional geostress distribution characteristics of the target area during water injection development based on the first geological model; determining the first distribution characteristics of hydraulic fractures generated in the target area during hydraulic fracturing based on the first geological model; modeling based on the first distribution characteristics, constructing a second geological model of the first coupled fracture network of natural fractures and hydraulic fractures in the target area; obtaining the influencing parameters of water injection induced fractures in the target area; inputting the influencing parameters and the four-dimensional geostress distribution characteristics into the second geological model, so as to output the second distribution characteristics of water injection induced fractures in the target area in the first coupled fracture network through the second geological model; modeling based on the second distribution characteristics, so as to construct a third geological model of the second coupled fracture network of natural fractures, hydraulic fractures and water injection induced fractures in the target area. The above scheme can better predict the distribution law of the fracture network system of natural fractures, hydraulic fractures and water injection induced fractures coupled during water injection development, and can provide geological basis for adjusting the development mode of dense low permeability reservoirs in the middle and late stages and tapping the potential of remaining oil, thereby improving the recovery rate of dense low permeability reservoirs.

[0086] Figure 1 A schematic diagram of a flow chart of a complex fracture network geological modeling method for water injection development in a tight low permeability reservoir in one embodiment. It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0087] Figure 5 The structure block diagram of a device for complex fracture network geological modeling of dense low permeability reservoir water injection development according to an embodiment of the present application is schematically shown. Figure 5 As shown, the embodiment of the present application provides a device for geological modeling of complex fracture networks in dense low-permeability reservoir water injection development, which may include:

[0088] Memory 510, configured to store instructions;

[0089] The processor 520 is configured to call instructions from the memory 510 and implement the above-mentioned complex fracture network geological modeling method for water injection development of tight low permeability reservoirs when executing the instructions.

[0090] Specifically, in the embodiment of the present application, the processor 520 may be configured to:

[0091] Establish a first geological model for natural fractures in the target area; determine the four-dimensional geostress distribution characteristics of the target area during water injection development based on the first geological model; determine the first distribution characteristics of hydraulic fractures generated in the target area during hydraulic fracturing based on the first geological model; model according to the first distribution characteristics to construct a second geological model of a first coupled fracture network of natural fractures and hydraulic fractures in the target area; obtain the influencing parameters of water injection induced fractures in the target area; input the influencing parameters and the four-dimensional geostress distribution characteristics into the second geological model to output the second distribution characteristics of water injection induced fractures in the target area in the first coupled fracture network through the second geological model; model according to the second distribution characteristics to construct a third geological model of the second coupled fracture network of natural fractures, hydraulic fractures and water injection induced fractures in the target area.

[0092] In the embodiment of the present application, the processor 520 may also be configured to:

[0093] Obtain the first parameter of natural fractures and the development intensity of fractures in a single well; determine the planar distribution law of natural fractures; use the planar distribution law as a spatial constraint trend, and construct a development intensity constraint body corresponding to natural fractures according to the development intensity of fractures in a single well; use the first parameter as a constraint to construct a first discrete network model of natural fractures; merge the development intensity constraint body and the first discrete network model to obtain a first geological model of natural fractures in the target area.

[0094] In the embodiment of the present application, the processor 520 may also be configured to:

[0095] Based on the first geological model, a reservoir geomechanical model of the target area is constructed, and the boundary conditions of the target area are determined; based on the finite element numerical simulation method, the three-dimensional geostress field distribution characteristics in the reservoir of the target area are predicted according to the reservoir geomechanical model and boundary conditions; based on the reservoir numerical simulation method, the four-dimensional geostress distribution characteristics of the target area during the water injection development process are determined according to the three-dimensional geostress field distribution characteristics.

[0096] In the embodiment of the present application, the processor 520 may also be configured to:

[0097] Determine whether there are natural fractures in the formation of the target area; if there are natural fractures in the formation of the target area, determine the first formation initiation conditions for hydraulic fractures generated in the target area during the hydraulic fracturing process; if there are natural fractures in the formation of the target area, determine the first distribution characteristics of the hydraulic fractures generated in the target area during the hydraulic fracturing process based on the first formation initiation conditions; if there are no natural fractures in the formation of the target area, determine the second formation initiation conditions for hydraulic fractures generated in the target area during the hydraulic fracturing process; determine the first distribution characteristics of the hydraulic fractures generated in the target area during the hydraulic fracturing process based on the second formation initiation conditions.

[0098] In the embodiment of the present application, the processor 520 may also be configured to:

[0099] The functional expressions of the first formation fracturing conditions are shown in the following formulas (1) and (2):

[0100] P p >P f (1)

[0101] P f =3σ h -σ H +σ t -P p (2)

[0102] Among them, P p It refers to the formation fracture pressure in the target area, P f refers to the formation fracture pressure in the target area, σ h is the current horizontal minimum principal stress of the reservoir in the target area, σ H refers to the current horizontal maximum principal stress of the reservoir in the target area, σ t It refers to the tensile strength of the reservoir rock in the target area, P p It refers to the formation pore fluid pressure in the target area.

[0103] In the embodiment of the present application, the processor 520 may also be configured to:

[0104] The functional expressions of the second formation fracturing conditions are shown in the following formulas (3) and (4):

[0105] P p >P i (3)

[0106]

[0107] P i It refers to the opening pressure of natural fractures in the target area, P oThe overburden pressure in the target area, v refers to the Poisson's ratio in the target area, θ refers to the fracture dip in the target area, and β refers to the angle between the maximum principal stress direction and the fracture strike in the target area.

[0108] In the embodiment of the present application, the processor 520 may also be configured to:

[0109] A first mathematical model is constructed according to the first distribution feature; a simulation is performed based on the first mathematical model to obtain a second parameter of the hydraulic fractures under the influence of natural fractures; a second discrete network model corresponding to the hydraulic fractures under the influence of natural fractures is constructed according to the second parameter based on a deterministic modeling method; the first geological model and the second discrete network model are integrated in time and space to construct a second geological model of a first coupled fracture network of natural fractures and hydraulic fractures in the target area.

[0110] In the embodiment of the present application, the processor 520 may also be configured to:

[0111] A second mathematical model is constructed according to the second distribution characteristics; a simulation is performed based on the second mathematical model to obtain a third parameter of water injection induced fractures under the influence of natural fractures and hydraulic fractures; a third discrete network model corresponding to water injection induced fractures under the influence of natural fractures and hydraulic fractures is constructed according to the third parameter based on a deterministic modeling method; the second geological model and the third discrete network model are integrated in time and space to construct a third geological model of a second coupled fracture network of natural fractures, hydraulic fractures and water injection induced fractures in the target area.

[0112] Through the above technical scheme, through comprehensive geological research on natural fractures, a discrete network model of natural fractures is established with the natural fracture development strength constraint body as a constraint and the discrete fracture network modeling method; based on rock mechanics experiments, acoustic logging and production dynamics and other data, combined with reservoir geomechanics numerical simulation and reservoir numerical simulation methods, the four-dimensional geostress distribution law of the reservoir is predicted; based on the hydraulic fracture expansion mechanism and numerical simulation, the influence of different injection pressures, fluid properties, rock mechanics characteristics and natural fractures on hydraulic fractures is analyzed, the hydraulic fracture expansion law is clarified, and a hydraulic fracture discrete network model is established; on the basis of the fracture network system of natural fractures and hydraulic fractures coupled, combined with production dynamics and other data, the crack opening, expansion and extension law during water injection is determined, the dynamic distribution characteristics of water injection-induced fractures are clarified, and a dynamic discrete network model of water injection-induced fractures is established; finally, the natural fracture model, hydraulic fracture model and water injection-induced fracture model are integrated in space and time to establish a three-dimensional dynamic geological model of a complex fracture network system coupling natural fractures, hydraulic fractures and water injection fractures. The method and system can better characterize the distribution of natural fractures, hydraulic fractures and water injection-induced fractures during water injection in tight low permeability reservoirs, provide a geological basis for adjusting oil and gas exploration and development plans for tight low permeability reservoirs and tapping the potential of remaining oil, thereby improving the oil and gas recovery rate of tight low permeability reservoirs.

[0113] The present application provides a machine-readable storage medium having instructions stored thereon, the instructions being used to enable a machine to execute the above-mentioned complex fracture network geological modeling method for water injection development of dense low-permeability reservoirs.

[0114] In one embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as follows: Figure 6 As shown. The computer device includes a processor A01, a network interface A02, a memory (not shown in the figure) and a database (not shown in the figure) connected by a system bus. Among them, the processor A01 of the computer device is used to provide computing and control capabilities. The memory of the computer device includes an internal memory A03 and a non-volatile storage medium A04. The non-volatile storage medium A04 stores an operating system B01, a computer program B02 and a database (not shown in the figure). The internal memory A03 provides an environment for the operation of the operating system B01 and the computer program B02 in the non-volatile storage medium A04. The database of the computer device is used to store data of a complex fracture network geological modeling method for water injection development of dense low permeability reservoirs. The network interface A02 of the computer device is used to communicate with an external terminal through a network connection. When the computer program B02 is executed by the processor A01, a complex fracture network geological modeling method for water injection development of dense low permeability reservoirs is implemented.

[0115] Those skilled in the art will understand that Figure 6The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0116] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0117] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0118] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0119] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0120] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0121] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0122] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0123] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0124] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A method for geological modeling of complex fracture networks in water injection development of dense low-permeability reservoirs, characterized in that: The method comprises: Establishing a first geological model of natural fractures in the target area; Determining four-dimensional geostress distribution characteristics of the target area during water injection development based on the first geological model; Determining first distribution characteristics of hydraulic fractures generated in the target area during the hydraulic fracturing process based on the first geological model; Modeling is performed according to the first distribution characteristics to construct a second geological model of a first coupled fracture network of natural fractures and hydraulic fractures in the target area; Obtaining influencing parameters of water injection-induced fractures in the target area; Inputting the influencing parameters and the four-dimensional geostress distribution characteristics into the second geological model, so as to output the second distribution characteristics of the water injection-induced fractures in the target area in the first coupled fracture network through the second geological model; Modeling is performed based on the second distribution characteristics to construct a third geological model of a second coupled fracture network of natural fractures, hydraulic fractures and water injection induced fractures in the target area.

2. The method for geological modeling of complex fracture networks in water injection development of dense low permeability reservoirs according to claim 1, characterized in that: The establishing of a first geological model of natural fractures in a target area comprises: Obtaining the first parameter of the natural fracture and the single well fracture development strength; Determining the planar distribution pattern of the natural fractures; Taking the plane distribution law as a spatial constraint trend, constructing a development intensity constraint body corresponding to the natural fracture according to the single well fracture development intensity; Using the first parameter as a constraint to construct a first discrete network model of the natural fracture; The development strength constraint and the first discrete network model are fused to obtain a first geological model of natural fractures in the target area.

3. The method for geological modeling of complex fracture networks in water injection development of dense low permeability reservoirs according to claim 1, characterized in that: The determining of the four-dimensional geostress distribution characteristics of the target area during the water injection development process based on the first geological model includes: constructing a reservoir geomechanical model of the target area based on the first geological model, and determining boundary conditions of the target area; Predicting the three-dimensional geostress field distribution characteristics in the reservoir of the target area based on the reservoir geomechanics model and the boundary conditions based on the finite element numerical simulation method; Based on the reservoir numerical simulation method, the four-dimensional geostress distribution characteristics of the target area during the water injection development process are determined according to the three-dimensional geostress field distribution characteristics.

4. The method for geological modeling of complex fracture networks in water injection development of dense low permeability reservoirs according to claim 1, characterized in that: The first distribution characteristics of hydraulic fractures generated in the target area during the hydraulic fracturing process are determined based on the first geological model, including: determining whether natural fractures exist in the formation of the target area; In the case where natural fractures exist in the formation of the target area, determining a first formation fracturing condition for generating hydraulic fractures in the target area during the hydraulic fracturing process; In the case where natural fractures exist in the formation of the target area, determining first distribution characteristics of hydraulic fractures generated in the target area during the hydraulic fracturing process according to the first formation fracturing initiation conditions; In the case where there are no natural fractures in the formation of the target area, determining a second formation fracturing condition for generating hydraulic fractures in the target area during the hydraulic fracturing process; The first distribution characteristics of the hydraulic fractures generated in the target area during the hydraulic fracturing process are determined according to the second formation fracturing conditions.

5. The method for geological modeling of complex fracture networks in water injection development of dense low permeability reservoirs according to claim 4, characterized in that: The functional expressions of the first formation fracturing conditions are shown in the following formulas (1) and (2): P p >P f (1) P f =3σ-σ H +s t -P p (2) Among them, P p refers to the formation fracture pressure in the target area, P f refers to the formation fracture pressure of the target area, σ h is the current horizontal minimum principal stress of the reservoir in the target area, σ H refers to the current horizontal maximum principal stress of the reservoir in the target area, σ t refers to the tensile strength of the reservoir rock in the target area, P p It refers to the formation pore fluid pressure in the target area.

6. The method for geological modeling of complex fracture networks in water injection development of dense low permeability reservoirs according to claim 4, characterized in that: The functional expressions of the second formation fracturing conditions are shown in the following formulas (3) and (4): P p >P i (3) Among them, P p refers to the formation fracture pressure in the target area, P i It refers to the opening pressure of the natural fractures in the target area, P o The overburden pressure of the target area, ν refers to the Poisson's ratio of the target area, θ refers to the fracture dip angle of the target area, β refers to the angle between the maximum principal stress direction and the fracture strike of the target area, σ h is the current horizontal minimum principal stress of the reservoir in the target area, σ H It refers to the current horizontal maximum principal stress of the reservoir in the target area.

7. The method for geological modeling of complex fracture networks in water injection development of dense low permeability reservoirs according to claim 1, characterized in that: The modeling according to the first distribution feature to construct a second geological model of a first coupled fracture network of natural fractures and hydraulic fractures in the target area includes: Constructing a first mathematical model according to the first spreading characteristics; Performing simulation based on the first mathematical model to obtain a second parameter of the hydraulic fracture under the influence of the natural fracture; Constructing a second discrete network model corresponding to the hydraulic fracture under the influence of the natural fracture according to the second parameter based on a deterministic modeling method; The first geological model and the second discrete network model are integrated in time and space to construct a second geological model of a first coupled fracture network of natural fractures and hydraulic fractures in the target area.

8. The method for geological modeling of complex fracture networks in water injection development of dense low permeability reservoirs according to claim 1, characterized in that: The method of modeling according to the second distribution characteristics to construct a third geological model of a second coupled fracture network of natural fractures, hydraulic fractures and water injection induced fractures in the target area includes: Constructing a second mathematical model according to the second spreading characteristics; Performing simulation based on the second mathematical model to obtain a third parameter of the water injection induced fracture under the influence of the natural fracture and the hydraulic fracture; Constructing a third discrete network model corresponding to the natural fracture and the water injection induced fracture under the influence of the hydraulic fracture according to the third parameter based on a deterministic modeling method; The second geological model and the third discrete network model are integrated in time and space to construct a third geological model of a second coupled fracture network of natural fractures, hydraulic fractures and water injection induced fractures in the target area.

9. A geological modeling device for complex fracture networks in dense low-permeability reservoir water injection development, characterized in that: include: a memory configured to store instructions; A processor is configured to call the instructions from the memory and implement the complex fracture network geological modeling method for water injection development of tight low permeability reservoirs according to any one of claims 1 to 8 when executing the instructions.

10. A machine-readable storage medium, characterized in that: The machine-readable storage medium stores instructions for causing a machine to execute the complex fracture network geological modeling method for water injection development of tight low-permeability reservoirs according to any one of claims 1 to 8.

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