Parameter simulation method, device and equipment based on deep shale gas reservoir, medium and product

Abstract

The application discloses a deep shale gas reservoir parameter simulation method, device, equipment, medium and product, and relates to the technical field of oil and gas development. The method comprises the following steps: obtaining a preset geological model; simulating a fracturing-production process of the preset geological model based on a preset fracturing-production coupling model; the preset fracturing-production coupling model comprises a wellbore flow model, a fracture flow model and a shale reservoir flow model; iteratively solving based on the preset fracturing-production coupling model and the preset geological model to obtain simulation parameter distribution data in the fracturing-production process; the simulation parameter distribution data comprises one or more of the following: a fracture morphology distribution after fracturing, pressure distribution data of a shale reservoir after fracturing, water saturation distribution data of the shale reservoir after fracturing, pressure distribution data of the shale reservoir after production and water saturation distribution data of the shale reservoir after production. The application can improve the accuracy of deep shale gas reservoir parameter simulation.

Description

Technical Field

[0001] This application relates to the field of oil and gas development technology, and in particular to a method, apparatus, equipment, medium and product for parameter simulation based on deep shale gas reservoirs. Background Technology

[0002] Deep shale reservoirs typically require hydraulic fracturing for development. During fracturing operations, a large amount of fracturing fluid is injected into the formation, and some of this fluid is lost through filtration into the reservoir pores, leading to a redistribution of reservoir pressure and fluid saturation. This change not only affects fracture propagation behavior during fracturing but also directly impacts the seepage characteristics and development effectiveness in subsequent production stages.

[0003] Most existing fracturing simulation studies neglect the seepage process of fracturing fluid in the reservoir, making it difficult to accurately characterize the filtration loss and distribution characteristics of fracturing fluid in the reservoir rock blocks, resulting in low accuracy of simulation data for subsequent production. Summary of the Invention

[0004] The purpose of this application is to provide a method, apparatus, equipment, medium, and product for parameter simulation based on deep shale gas reservoirs, which can improve the accuracy of parameter simulation based on deep shale gas reservoirs.

[0005] To achieve the above objectives, this application provides the following solution: Firstly, this application provides a parameter simulation method based on deep shale gas reservoirs, including: Obtain a preset geological model; wherein the preset geological model includes shale reservoir, wellbore, and fracturing perforation; The fracturing-production process of the preset geological model is simulated based on a preset fracturing-production coupling model. The preset fracturing-production coupling model is used to simulate the wellbore flow, fracture propagation and reservoir seepage process from fracturing to production. The preset fracturing-production coupling model includes a wellbore flow model, a fracture flow model and a shale reservoir flow model. The simulation parameter distribution data during the fracturing-production process is obtained by iteratively solving the preset fracturing-production coupling model and the preset geological model; wherein, the simulation parameter distribution data includes one or more of the following: fracture morphology distribution after fracturing, pressure distribution data of the shale reservoir after fracturing, water saturation distribution data of the shale reservoir after fracturing, pressure distribution data of the shale reservoir after production, and water saturation distribution data of the shale reservoir after production.

[0006] Optionally, the preset geological model also includes data on the geometry, top and bottom depths, thickness, reservoir porosity, permeability, initial pressure, initial water saturation, rock mechanical parameters, and stress field distribution of the shale reservoir. The rock mechanical parameters include elastic modulus, Poisson's ratio, and fracture toughness, and the stress field distribution data includes the magnitude and direction of the stress field. The preset geological model also includes the division of fracture plane regions based on the wellbore and the location of the fracturing perforation.

[0007] Optionally, the wellbore flow model is used to describe the flow process of fracturing fluid from the wellhead through the wellbore and perforation holes into the fracture. The wellbore flow model includes a bottom hole pressure equation and a flow distribution equation. The bottom hole pressure equation is: (1); in, For crack pressure; This refers to the wellhead pressure. This refers to the pressure of the liquid column. For wellbore friction pressure drop; For the pressure drop at the perforation point; The flow distribution equation can be expressed as: (2); in, Q total This refers to the total injection volume in the wellbore. Q i The flow rate entering each cluster of cracks; The fracture flow model is used to describe the mass conservation relationships of the gas phase, water phase, and proppant phase flow in the fracture; the fracture flow model can be expressed as: (7); in, t Indicates time, Indicates density, v The subscripts represent flow rate, S represents saturation, g represents the gas phase, w represents the aqueous phase, and pr represents the proppant phase. The total density of the fracture fluid and proppant; c Represents volume fraction. For source and sink items, ; The total velocity of fluid and proppant in the fracture; in: This refers to the gas phase flow exchange term between the fracture and the shale reservoir. The water phase flow exchange term between the fracture and the shale reservoir is described by the following formula: (6); In the formula, the subscripts f and m represent the fracture and the shale reservoir, respectively; For the flow rate of the gas phase or the aqueous phase, Reservoir permeability; and These are fracture pressure and reservoir fluid pressure, respectively. This refers to the average distance between the shale reservoir grid and the fracture grid; The shale reservoir flow model is used to describe the gas-water two-phase flow process, and the shale reservoir flow model is expressed by the following formula: (10).

[0008] Optionally, the preset fracturing-production coupling model further includes an elasticity model and a fracture propagation criterion model; wherein The elasticity model is used to describe the mechanical equilibrium relationship between fluid pressure, induced stress, and far-field stress in a fracture element. The elasticity model includes: (13); in, For crack elements i Internal fluid pressure; For unit j The discontinuity of normal displacement; For unit j For unit i The influence coefficient; For far-field stress in the element i The normal component on; The crack propagation criterion model describes the Type I stress intensity factor at the crack tip: (14); in, K I The type I stress intensity factor at the crack tip is the factor that determines when the crack propagates when it exceeds the fracture toughness of the rock.

[0009] Optionally, the step of iteratively solving the pre-set fracturing-production coupling model and the pre-set geological model to obtain the simulation parameter distribution data in the fracturing-production process includes: For each current time step, updated fracture width and fluid pressure distribution data are obtained based on the wellbore flow model, the elasticity model, the fracture flow model, and the shale reservoir flow model. Based on the fracture width and the fluid pressure distribution data, updated gas phase saturation distribution data, water phase saturation distribution data, and proppant concentration distribution data are obtained by simultaneously solving the saturation equation in the fracture, the saturation equation in the reservoir, and the proppant migration equation. The next time step is taken as the current time step. Based on the updated fracture width, fluid pressure distribution data, gas phase saturation distribution data, water phase saturation distribution data, proppant concentration distribution data, shale reservoir porosity, shale reservoir permeability, fluid density, and fluid viscosity; the process returns to the steps of obtaining updated fracture width and fluid pressure distribution data based on the wellbore flow model, the elasticity model, the fracture flow model, and the shale reservoir flow model until the simulation of the entire process of fracturing, well shut-in, flowback, and production is completed. The fracture morphology distribution after fracturing, the pressure distribution data of the shale reservoir after fracturing, the water saturation distribution data of the shale reservoir after fracturing, the pressure distribution data of the shale reservoir after production, and the water saturation distribution data of the shale reservoir after production are used as the simulation parameter distribution data.

[0010] Optionally, the saturation equation in the crack is described by the following formula: (4); The saturation equation in the reservoir is described by the following formula: (8); The proppant transport equation is described by the following formula: (5).

[0011] Secondly, this application provides a parameter simulation device based on deep shale gas reservoirs, comprising: The first model module is used to obtain a preset geological model; wherein, the preset geological model includes shale reservoir, wellbore, and fracturing perforation; The second model module is used to simulate the fracturing-production process of the preset geological model based on the preset fracturing-production coupling model; wherein, the preset fracturing-production coupling model is used to simulate the process of wellbore flow, fracture propagation and reservoir seepage from fracturing to production, and the preset fracturing-production coupling model includes a wellbore flow model, a fracture flow model and a shale reservoir flow model; An iterative module is used to iteratively solve the preset fracturing-production coupling model and the preset geological model to obtain the simulated parameter distribution data in the fracturing-production process; wherein, the simulated parameter distribution data includes one or more of the following: fracture morphology distribution after fracturing, pressure distribution data of the shale reservoir after fracturing, water saturation distribution data of the shale reservoir after fracturing, pressure distribution data of the shale reservoir after production, and water saturation distribution data of the shale reservoir after production.

[0012] Thirdly, this application provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the parameter simulation method based on deep shale gas reservoirs as described above.

[0013] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the parameter simulation method based on deep shale gas reservoirs described above.

[0014] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the parameter simulation method based on deep shale gas reservoirs described above.

[0015] According to the specific embodiments provided in this application, the following technical effects are disclosed: This application provides a method, apparatus, equipment, medium, and product for parameter simulation of deep shale gas reservoirs. It achieves geological simulation of the shale reservoir, wellbore, and perforation locations using a pre-set geological model (including the shale reservoir, wellbore, and fracturing perforations). It simulates the fracturing-production process involving coupled wellbore flow, fracture propagation, and reservoir seepage using a pre-set fracturing-production coupling model and obtains the simulated parameter distribution data. This enables accurate simulation of pressure distribution and water saturation variation during the integrated fracturing-production process, improving the accuracy of parameter simulation for deep shale gas reservoirs. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A flowchart illustrating a parameter simulation method based on deep shale gas reservoirs, provided as an embodiment of this application; Figure 2 A schematic diagram of the overall process framework of a parameter simulation method based on deep shale gas reservoirs provided in an embodiment of this application; Figure 3 The physical model of Embodiment 1 provided in this application; Figure 4 A geometric distribution diagram of the fractures obtained after fracturing in Embodiment 1 provided in this application; Figure 5The fluid pressure distribution map of the shale reservoir after fracturing was obtained in Example 1 provided in this application; Figure 6 Water saturation distribution map obtained after fracturing in Example 1 provided in this application; Figure 7 The fluid pressure distribution map of the shale reservoir one year after production, obtained from Example 1 provided in this application; Figure 8 The water saturation distribution map obtained one year after production for Example 1 provided in this application; Figure 9 A schematic diagram of the functional modules of a parameter simulation device based on a deep shale gas reservoir provided in an embodiment of this application; Figure 10 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] It should be noted that the terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented, for example, in orders other than those illustrated or described herein.

[0020] It should be noted that "at the time of..." in the embodiments of this application can be either at the instant when a certain situation occurs, or for a period of time after the occurrence of a certain situation. The embodiments of this application do not make specific limitations on this.

[0021] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] In one exemplary embodiment, such as Figure 1 As shown, a parameter simulation method based on deep shale gas reservoirs is provided. This method is executed by computer equipment, specifically by a terminal or server alone, or by both a terminal and a server. It includes the following steps 101 to 103: Step 101: Obtain a preset geological model; wherein, the preset geological model includes shale reservoir, wellbore, and fracturing perforation; Specifically, a preset geological model is established on finite element software. The preset geological model is established based on the geological exploration data of the target deep shale gas reservoir.

[0023] Specifically, the pre-set geological model should include the morphology of shale reservoirs, wellbore and fracturing perforations and their positional relationships, as well as the corresponding model parameters.

[0024] Step 102: Simulate the fracturing-production process of the preset geological model based on the preset fracturing-production coupling model; wherein, the preset fracturing-production coupling model is used to simulate the process of wellbore flow, fracture propagation and reservoir seepage from fracturing to production. The preset fracturing-production coupling model includes a wellbore flow model, a fracture flow model and a shale reservoir flow model. Specifically, the pre-defined fracturing-production coupling model of this application can realize the coupled simulation of the entire fracturing and production process, reveal the interaction mechanism between fracture propagation and changes in reservoir pressure and saturation, avoid the errors caused by analyzing fracturing and production separately, and significantly improve the accuracy of dynamic prediction of shale gas reservoir production.

[0025] Step 103: Based on the preset fracturing-production coupling model and the preset geological model, perform iterative solution to obtain the simulated parameter distribution data in the fracturing-production process; wherein, the simulated parameter distribution data includes one or more of the following: fracture morphology distribution after fracturing, pressure distribution data of the shale reservoir after fracturing, water saturation distribution data of the shale reservoir after fracturing, pressure distribution data of the shale reservoir after production, and water saturation distribution data of the shale reservoir after production.

[0026] Specifically, the equations are solved using a sequential iterative approach that reveals saturation through implicit pressure, employing the finite volume method and the displacement discontinuity method, to obtain simulation parameter distribution data. This method can be applied to scenarios such as hydraulic fracturing scheme design and optimization for deep shale gas reservoirs, post-fracturing production prediction and dynamic analysis, and integrated numerical simulation of geological engineering for unconventional oil and gas reservoirs.

[0027] Implementing steps 101 to 103 above can be used in scenarios such as hydraulic fracturing scheme design and optimization for deep shale gas reservoirs, post-fracturing production prediction and dynamic analysis, and integrated numerical simulation of unconventional oil and gas reservoir geology and engineering. By using a pre-set geological model (including shale reservoir, wellbore, and fracturing perforations), geological simulation of the shale reservoir, wellbore, and perforation locations is achieved. A pre-set fracturing-production coupling model simulates the fracturing-production process involving coupled wellbore flow, fracture propagation, and reservoir seepage, and solves for the simulation parameter distribution data. This enables accurate simulation of pressure distribution and water saturation variation during the integrated fracturing-production process, improving the accuracy of parameter simulation based on deep shale gas reservoirs.

[0028] Furthermore, Figure 2 This outlines the specific steps of a parametric simulation method for deep shale gas reservoirs. The following sections will... Figure 1 and Figure 2 This application will be described in detail based on the above.

[0029] In another exemplary embodiment of this application, in order to more comprehensively simulate the geology of the target deep shale gas reservoir, in step 102, the preset geological model includes a physical model based on the shale reservoir, wellbore, fracturing perforation, and fracture plane region division based on the location of the wellbore and fracturing perforation, and also includes geological model parameters. For example, such as Figure 3 The physical model shown is the one provided in Example 1. Figure 3 : Specifically, the perforation point is a point located on the wellbore to simulate a crack point on the wellbore. One or more perforation points can be set. Specifically, the fracture plane region is a plane in the shale reservoir that is perpendicular to the wellbore and contains the perforation point. The black grid area represents the possible expansion path of the fracture, the gray area represents the currently formed fracture plane, and the blue cube area represents the reservoir matrix.

[0030] Specifically, as geological model parameters, these include data based on shale reservoir geometry, top and bottom depths, thickness, reservoir porosity, permeability, initial pressure, initial water saturation, rock mechanical parameters, and stress field distribution. Rock mechanics parameters include elastic modulus, Poisson's ratio, and fracture toughness, while stress field distribution data includes the magnitude and direction of the stress field.

[0031] The pre-defined geological model comprehensively simulates the geology of the target deep shale gas reservoir. This provides a foundation for subsequently simulating the integrated process of fracturing, well shut-in, flowback, and production (i.e., the fracturing-production process in this paper) and improving the accuracy of simulation parameters. The fracturing-production process specifically includes: During fracturing, fracturing fluid is injected from the wellhead and flows through the wellbore, entering the fracture at the perforation point. When the fracture reaches the fracture propagation condition, the fracture propagates, and the fracturing fluid is filtered out from the fracture and enters the reservoir. During the well-sealing process, no fluid flows in or out of the wellhead, and the fracturing fluid in the fractures continues to be lost to the reservoir. During the flowback and production phases, fracturing fluid and formation fluid are extracted from the wellhead through the wellbore.

[0032] In another exemplary embodiment of this application, in order to achieve coupled simulation of the entire fracturing and production process and to reveal the interaction mechanism between fracture propagation and changes in reservoir pressure and saturation, step 102 pre-sets the fracturing-production coupling model in the wellbore flow model, fracture flow model, and shale reservoir flow model, and also includes an elasticity model and a fracture propagation criterion model. The following is a detailed description of the wellbore flow model, fracture flow model, shale reservoir flow model, elasticity model, and fracture propagation criterion model: Specifically, the wellbore flow model is used to describe the flow process of fracturing fluid from the wellhead through the wellbore and perforation holes into the fracture. The wellbore flow model includes the bottom hole pressure equation and the flow distribution equation, taking into account wellbore friction, perforation pressure drop, and fluid column pressure. The bottom hole pressure equation is: (1); in, For crack pressure; This refers to the wellhead pressure. This refers to the pressure of the liquid column. For wellbore friction pressure drop; For the pressure drop at the perforation point; For multi-cluster fracturing, the flow distribution equation must also be satisfied, which can be expressed as: (2); in, Q total This represents the total injection volume into the wellbore. Q i This represents the flow rate entering each cluster of fractures. A single fracture constitutes a cluster of fractures.

[0033] Specifically, the fracture flow model is used to describe the mass conservation relationships of the flow of the gas phase, water phase, and proppant phase in the fracture.

[0034] Fractures are considered as high-permeability channels characterized by embedded discrete fracture grids. Within the fractures, the two-phase flow of fracturing fluid (aqueous phase) and shale gas (gas phase) must be considered simultaneously, as well as the migration of proppant. Ignoring the proppant flow into the reservoir, the mass conservation equations for the gas, aqueous, and proppant phases within the fractures can be expressed as equations (3) to (5): (3); (4); (5); In the formula, t Indicates time, Indicates density, v The subscripts represent flow rate, S represents saturation, g represents the gas phase, w represents the aqueous phase, and pr represents the proppant phase. This refers to the volume fraction of the proppant. The flow rate of the gas phase, aqueous phase, or proppant phase in the fracture. This refers to relative penetration rate. k For absolute penetration rate, p For pressure, Viscosity, g It is the acceleration due to gravity. h For depth; The width of the crack; , and This refers to the flow exchange term between the wellbore and the fracture. and The flow exchange term between the fracture and the reservoir is calculated using the following formula: (6); In the formula, the subscripts f and m represent fracture and reservoir, respectively; For the flow rate of the gas phase or the aqueous phase, Reservoir permeability; and These are fracture pressure and reservoir fluid pressure, respectively. This represents the average distance between the reservoir grid and the fracture grid.

[0035] Combining formulas (3) to (5), the crack flow model of this application can be expressed as: (7); in, The total density of the fracture fluid and proppant; c Represents volume fraction. For source and sink items, ; The total velocity of fluid and proppant in the fracture; Specifically, shale reservoir flow models are used to describe the seepage process of the gas-water two-phase system.

[0036] The shale reservoir matrix is ​​the primary reservoir space, containing formation water and shale gas. The flow within the matrix is ​​a two-phase gas-water flow. Its flow equation is expressed as: (8); (9); In the formula, This refers to reservoir porosity.

[0037] By combining equations (8) and (9), we can obtain the overall flow equation for the gas and water phases in the reservoir (shale reservoir flow model): (10); Specifically, the elasticity model is used to describe the mechanical equilibrium relationship between fluid pressure, induced stress and far-field stress in the crack element. The elasticity model is shown in formula (13) below. As its derivation process, the displacement discontinuity in the crack can be described by the following formula. D z (In this invention, this refers to the crack width) w f At any point in space M (x,y,z) Induced normal displacement and normal stress: (11); (12); in, for M Normal displacement of a point; displacement discontinuity D z That is, the width of the crack. w f , for M Normal stress at a point; , , For the Poisson's ratio of rocks, The elastic modulus of the rock; , , and They are respectively g right z The first, second, and third derivatives; where, for any crack element... i Then, according to the superposition principle, the substance applied to the unit can be obtained. i The net stress on the surface satisfies the following formula (i.e., the elasticity model): (13); in, For crack elements i Internal fluid pressure; For unit j The discontinuity of normal displacement; For unit j For unit iThe influence coefficient; For far-field stress in the element i The normal component on; Specifically, the crack propagation criterion model describes the Type I stress intensity factor at the crack tip: (14); in, K I The stress intensity factor at the crack tip is Type I. In this invention, only Type I open cracks are considered. When the stress intensity factor at the crack tip is greater than the fracture toughness of the rock, the crack expands.

[0038] In another exemplary embodiment of this application, step 103 specifically includes: Step 301: For each current time step, obtain updated fracture width and fluid pressure distribution data based on the wellbore flow model, elasticity model, fracture flow model, and shale reservoir flow model. Step 302: Based on the fracture width and fluid pressure distribution data, the updated gas phase saturation distribution data, water phase saturation distribution data and proppant concentration distribution data are obtained by simultaneously solving the saturation equation in the fracture (Formula (4)), the saturation equation in the reservoir (Formula (8)) and the proppant migration equation (Formula (5)). Step 303 takes the next time step as the current time step, and returns to execute step 303 based on the updated fracture width, fluid pressure distribution data, gas phase saturation distribution data, water phase saturation distribution data and proppant concentration distribution data until the simulation of the entire process of fracturing, well shut-in, flowback and production is completed. Step 304 uses the fracture morphology distribution, pressure distribution data of the shale reservoir after fracturing, water saturation distribution data of the shale reservoir after fracturing, pressure distribution data of the shale reservoir after production, and water saturation distribution data of the shale reservoir after production as simulation parameter distribution data.

[0039] Specifically, the above nonlinear equations are all solved using the Newton-Raphson iterative method to ensure computational accuracy and convergence.

[0040] Example 1: like Figure 3 The physical model of Embodiment 1 provided in this application establishes a preset geological model through the physical model and the geological model parameters of the exploration, and obtains the simulation parameter distribution data according to the method of this application.

[0041] The acquired simulation parameter distribution data includes the geometry of the fractures after fracturing (see...). Figure 4 ), data on fluid pressure distribution in shale reservoirs after fracturing (see Figure 5Water saturation distribution data after fracturing (see) Figure 6 ), shale reservoir fluid pressure distribution data one year after production (see Figure 7 ) and water saturation distribution data one year after production (see Figure 8 ).

[0042] This application provides a parameter simulation method based on deep shale gas reservoirs, which has the following technical advantages: By dynamically coupling reservoir flow in fracturing simulation, the limitations of the traditional empirical filtration coefficient method are eliminated, and the actual filtration loss and distribution of fracturing fluid in the reservoir can be captured more accurately, laying a solid foundation for post-fracturing assessment and production capacity prediction.

[0043] It achieves coupled simulation of the entire fracturing and production process, which can reveal the interaction mechanism between fracture propagation and changes in reservoir pressure and saturation. It avoids the errors caused by analyzing fracturing and production separately, and significantly improves the accuracy of dynamic prediction of shale gas reservoir production.

[0044] By establishing a unified mathematical model and an efficient solution strategy, a refined simulation of the entire fracturing-production process has been achieved. This simulation can be applied to scenarios such as hydraulic fracturing scheme design and optimization for deep shale gas reservoirs, post-fracturing production prediction and dynamic analysis, and integrated numerical simulation of unconventional oil and gas reservoir geology and engineering. It provides an important theoretical analysis and scheme optimization tool for the efficient development of deep shale gas.

[0045] Based on the same inventive concept, this application also provides a parameter simulation device for deep shale gas reservoirs to implement the parameter simulation method for deep shale gas reservoirs described above. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more parameter simulation device embodiments for deep shale gas reservoirs provided below can be found in the limitations of the parameter simulation method for deep shale gas reservoirs described above, and will not be repeated here.

[0046] In one exemplary embodiment, such as Figure 9 As shown, a parameter simulation device based on deep shale gas reservoirs is provided, comprising: The first model module is used to obtain a preset geological model, which includes shale reservoirs, wellbore and fracturing perforations. The second model module is used to simulate the fracturing-production process of a preset geological model based on a preset fracturing-production coupling model. The preset fracturing-production coupling model is used to simulate the wellbore flow, fracture propagation and reservoir seepage process from fracturing to production. The preset fracturing-production coupling model includes a wellbore flow model, a fracture flow model and a shale reservoir flow model. The iteration module is used to iteratively solve for the simulated parameter distribution data during the fracturing-production process based on the preset fracturing-production coupling model and the preset geological model. The simulated parameter distribution data includes one or more of the following: fracture morphology distribution after fracturing, pressure distribution data of the shale reservoir after fracturing, water saturation distribution data of the shale reservoir after fracturing, pressure distribution data of the shale reservoir after production, and water saturation distribution data of the shale reservoir after production.

[0047] As an optional implementation, the first model module also includes a preset geological model based on the geometry, top and bottom depths, thickness, reservoir porosity, permeability, initial pressure, initial water saturation, rock mechanical parameters, and stress field distribution data of the shale reservoir. Rock mechanics parameters include elastic modulus, Poisson's ratio, and fracture toughness; stress field distribution data includes the magnitude and direction of the stress field. The preset geological model also includes the division of fracture plane regions based on the location of the wellbore and fracturing perforations.

[0048] As an optional implementation, in the second model module, the wellbore flow model is used to describe the flow process of fracturing fluid from the wellhead through the wellbore and perforation holes into the fracture. The wellbore flow model includes the bottom hole pressure equation and the flow distribution equation. The bottom hole pressure equation is: (1); in, For crack pressure; This refers to the wellhead pressure. This refers to the pressure of the liquid column. For wellbore friction pressure drop; For the pressure drop at the perforation point; The flow distribution equation can be expressed as: (2); in, Q total This represents the total injection volume into the wellbore. Q i The flow rate entering each cluster of cracks; The fracture flow model is used to describe the mass conservation relationships of the gas phase, water phase, and proppant phase in a fracture; the fracture flow model can be expressed as: (7); in, t Indicates time, Indicates density, v The subscripts represent flow rate, S represents saturation, g represents the gas phase, w represents the aqueous phase, and pr represents the proppant phase. The total density of the fracture fluid and proppant; cRepresents volume fraction. For source and sink items, ; The total velocity of fluid and proppant in the fracture; in: This refers to the gas phase flow exchange term between fractures and shale reservoirs. The water phase flow exchange term between fractures and shale reservoirs is described by the following formula: (6); In the formula, the subscripts f and m represent fractures and shale reservoirs, respectively; For the flow rate of the gas phase or the aqueous phase, Reservoir permeability; and These are fracture pressure and reservoir fluid pressure, respectively. This represents the average distance between the shale reservoir grid and the fracture grid; The shale reservoir flow model is used to describe the seepage process of the gas-water two phases. The shale reservoir flow model is expressed by the following formula: (7).

[0049] As an optional implementation, the second model module, the preset fracturing-production coupling model, also includes an elasticity model and a fracture propagation criterion model; wherein... Elasticity models are used to describe the mechanical equilibrium relationship between fluid pressure, induced stress, and far-field stress in a fracture element. Elasticity models include: (13); in, For crack elements i Internal fluid pressure; For unit j The discontinuity of normal displacement; For unit j For unit i The influence coefficient; For far-field stress in the element i The normal component on; The crack propagation criterion model describes the Type I stress intensity factor at the crack tip: (14); in, K I The type I stress intensity factor at the crack tip is the factor that determines when the crack propagates when it exceeds the fracture toughness of the rock.

[0050] As an optional implementation, the iteration module is specifically used for: For each current time step, updated fracture width and fluid pressure distribution data are obtained based on the wellbore flow model, elasticity model, fracture flow model, and shale reservoir flow model. Based on fracture width and fluid pressure distribution data, updated gas phase saturation distribution data, water phase saturation distribution data, and proppant concentration distribution data are obtained by simultaneously solving the saturation equations in the fracture, reservoir, and proppant migration equations. The next time step is taken as the current time step. Based on the updated fracture width, fluid pressure distribution data, gas phase saturation distribution data, water phase saturation distribution data, and proppant concentration distribution data, the steps to obtain updated fracture width and fluid pressure distribution data based on the wellbore flow model, elasticity model, fracture flow model, and shale reservoir flow model are returned until the simulation of the entire process of fracturing, well shut-in, flowback, and production is completed. The distribution data of fracture morphology after fracturing, pressure distribution data of shale reservoir after fracturing, water saturation distribution data of shale reservoir after fracturing, pressure distribution data of shale reservoir after production, and water saturation distribution data of shale reservoir after production are used as simulation parameter distribution data.

[0051] As an optional implementation, in the iterative module, the saturation equation in the crack is described by the following formula: (4); The saturation equation in the reservoir is described by the following formula: (8); The proppant transport equation is described by the following formula: (5).

[0052] In one exemplary embodiment, a computer device is provided, which may be a server or a terminal, and its internal structure diagram may be as follows. Figure 10As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores data. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communicating with external terminals via a network. When the computer program is executed by the processor, it implements a parameter simulation method based on deep shale gas reservoirs.

[0053] Those skilled in the art will understand that Figure 10 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0054] In one exemplary embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0055] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0056] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0057] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0058] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0059] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0060] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0061] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. In summary, the content of this specification should not be construed as a limitation of this application.

Claims

1. A parameter simulation method based on deep shale gas reservoirs, characterized in that, The parameter simulation method based on deep shale gas reservoirs includes: Obtain a preset geological model; wherein the preset geological model includes shale reservoir, wellbore, and fracturing perforation; The fracturing-production process of the preset geological model is simulated based on a preset fracturing-production coupling model; wherein, the preset fracturing-production coupling model is used to simulate the process of wellbore flow, fracture propagation and reservoir seepage from fracturing to production, and the preset fracturing-production coupling model includes a wellbore flow model, a fracture flow model and a shale reservoir flow model; The wellbore flow model is used to describe the flow process of fracturing fluid from the wellhead through the wellbore and perforation holes into the fracture. The wellbore flow model includes a bottom hole pressure equation and a flow distribution equation. The bottom hole pressure equation is as follows: （1）； in, For crack pressure; This refers to the wellhead pressure. This refers to the pressure of the liquid column. For wellbore friction pressure drop; For the pressure drop at the perforation point; The flow distribution equation can be expressed as: （2）； in, Q total This refers to the total injection volume in the wellbore. Q i The flow rate entering each cluster of cracks; The fracture flow model is used to describe the mass conservation relationships of the gas phase, water phase, and proppant phase flow in the fracture; the fracture flow model can be expressed as: （7）； in, t Indicates time, Indicates density, v The subscripts represent flow rate, S represents saturation, g represents the gas phase, w represents the aqueous phase, and pr represents the proppant phase. The total density of the fracture fluid and proppant; c Represents volume fraction. For source and sink items, ; The total velocity of fluid and proppant in the fracture; in: This refers to the gas phase flow exchange term between the fracture and the shale reservoir. The water phase flow exchange term between the fracture and the shale reservoir is described by the following formula: （6）； In the formula, the subscripts f and m represent the fracture and the shale reservoir, respectively; For the flow rate of the gas phase or the aqueous phase, Reservoir permeability; and These are the pressures of the fracture and the reservoir fluid, respectively. This refers to the average distance between the shale reservoir grid and the fracture grid; The shale reservoir flow model is used to describe the gas-water two-phase flow process, and the shale reservoir flow model is expressed by the following formula: （10）； The simulation parameter distribution data during the fracturing-production process is obtained by iteratively solving the preset fracturing-production coupling model and the preset geological model; wherein, the simulation parameter distribution data includes one or more of the following: fracture morphology distribution after fracturing, pressure distribution data of the shale reservoir after fracturing, water saturation distribution data of the shale reservoir after fracturing, pressure distribution data of the shale reservoir after production, and water saturation distribution data of the shale reservoir after production.

2. The parameter simulation method based on deep shale gas reservoirs according to claim 1, characterized in that, The preset geological model also includes data on the geometry, top and bottom depths, thickness, reservoir porosity, permeability, initial pressure, initial water saturation, rock mechanical parameters, and stress field distribution of the shale reservoir. The rock mechanical parameters include elastic modulus, Poisson's ratio, and fracture toughness, and the stress field distribution data includes the magnitude and direction of the stress field. The preset geological model also includes the division of fracture plane regions based on the wellbore and the location of the fracturing perforation.

3. The parameter simulation method based on deep shale gas reservoirs according to claim 1, characterized in that, The pre-defined fracturing-production coupling model also includes an elasticity model and a fracture propagation criterion model; in The elasticity model is used to describe the mechanical equilibrium relationship between fluid pressure, induced stress, and far-field stress in a fracture element. The elasticity model includes: （13）； in, For crack elements i Internal fluid pressure; For unit j The discontinuity of normal displacement; For unit j For unit i The influence coefficient; For far-field stress in the element i The normal component on; The crack propagation criterion model describes the Type I stress intensity factor at the crack tip: （14）； in, K I The type I stress intensity factor at the crack tip is the factor that determines when the crack propagates when it exceeds the fracture toughness of the rock.

4. The parameter simulation method based on deep shale gas reservoirs according to claim 3, characterized in that, The step of iteratively solving the simulation parameter distribution data in the fracturing-production process based on the preset fracturing-production coupling model and the preset geological model includes: For each current time step, updated fracture width and fluid pressure distribution data are obtained based on the wellbore flow model, the elasticity model, the fracture flow model, and the shale reservoir flow model. Based on the fracture width and the fluid pressure distribution data, updated gas phase saturation distribution data, water phase saturation distribution data, and proppant concentration distribution data are obtained by simultaneously solving the saturation equation in the fracture, the saturation equation in the reservoir, and the proppant migration equation. The next time step is taken as the current time step. Based on the updated fracture width, fluid pressure distribution data, gas phase saturation distribution data, water phase saturation distribution data, and proppant concentration distribution data, the process returns to the steps of obtaining updated fracture width and fluid pressure distribution data based on the wellbore flow model, the elasticity model, the fracture flow model, and the shale reservoir flow model until the simulation of the entire process of fracturing, well shut-in, flowback, and production is completed. The fracture morphology distribution after fracturing, the pressure distribution data of the shale reservoir after fracturing, the water saturation distribution data of the shale reservoir after fracturing, the pressure distribution data of the shale reservoir after production, and the water saturation distribution data of the shale reservoir after production are used as the simulation parameter distribution data.

5. The parameter simulation method based on deep shale gas reservoirs according to claim 4, characterized in that, The saturation equation in the crack is described by the following formula: （4）； The saturation equation in the reservoir is described by the following formula: （8）； The proppant transport equation is described by the following formula: （5）。 6. A parameter simulation device based on deep shale gas reservoirs, characterized in that, The parameter simulation device based on deep shale gas reservoirs includes: The first model module is used to obtain a preset geological model; wherein, the preset geological model includes shale reservoir, wellbore, and fracturing perforation; The second model module is used to simulate the fracturing-production process of the preset geological model based on the preset fracturing-production coupling model; wherein, the preset fracturing-production coupling model is used to simulate the process of wellbore flow, fracture propagation and reservoir seepage from fracturing to production, and the preset fracturing-production coupling model includes a wellbore flow model, a fracture flow model and a shale reservoir flow model; The wellbore flow model is used to describe the flow process of fracturing fluid from the wellhead through the wellbore and perforation holes into the fracture. The wellbore flow model includes a bottom hole pressure equation and a flow distribution equation. The bottom hole pressure equation is as follows: （1）； in, For crack pressure; This refers to the wellhead pressure. This refers to the pressure of the liquid column. For wellbore friction pressure drop; For the pressure drop at the perforation point; The flow distribution equation can be expressed as: （2）； in, Q total This refers to the total injection volume in the wellbore. Q i The flow rate entering each cluster of cracks; The fracture flow model is used to describe the mass conservation relationships of the gas phase, water phase, and proppant phase flow in the fracture; the fracture flow model can be expressed as: （7）； in, t Indicates time, Indicates density, v The subscripts represent flow rate, S represents saturation, g represents the gas phase, w represents the aqueous phase, and pr represents the proppant phase. The total density of the fracture fluid and proppant; c Represents volume fraction. For source and sink items, ; The total velocity of fluid and proppant in the fracture; in: This refers to the gas phase flow exchange term between the fracture and the shale reservoir. The water phase flow exchange term between the fracture and the shale reservoir is described by the following formula: （6）； In the formula, the subscripts f and m represent the fracture and the shale reservoir, respectively; For the flow rate of the gas phase or the aqueous phase, Reservoir permeability; and These are the pressures of the fracture and the reservoir fluid, respectively. This refers to the average distance between the shale reservoir grid and the fracture grid; The shale reservoir flow model is used to describe the gas-water two-phase flow process, and the shale reservoir flow model is expressed by the following formula: （10）； An iterative module is used to iteratively solve the preset fracturing-production coupling model and the preset geological model to obtain the simulated parameter distribution data in the fracturing-production process; wherein, the simulated parameter distribution data includes one or more of the following: fracture morphology distribution after fracturing, pressure distribution data of the shale reservoir after fracturing, water saturation distribution data of the shale reservoir after fracturing, pressure distribution data of the shale reservoir after production, and water saturation distribution data of the shale reservoir after production.

7. A computer device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the steps of the parameter simulation method based on deep shale gas reservoirs according to any one of claims 1-5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the parameter simulation method based on deep shale gas reservoirs as described in any one of claims 1-5.

9. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the parameter simulation method based on deep shale gas reservoirs as described in any one of claims 1-5.

Images