Method, system and equipment for optimizing fracture parameters of tight gas reservoir fractured horizontal well

Abstract

The invention provides a tight gas reservoir fractured horizontal well fracture parameter optimization method, system and equipment. The method comprises the steps that a river channel sand body space distribution model is determined according to geological parameters; determining a channel sand body heterogeneous attribute model according to the horizontal shaft parameters and the channel sand body spatial distribution model; determining an actual gas reservoir numerical simulation model of the heterogeneous river channel sand body according to the simulation production dynamics determined by the horizontal shaft parameters, the working system parameters and the heterogeneous attribute model of the river channel sand body and the actual production dynamics corresponding to the parameters; determining a heterogeneous river channel sand body crack parameter optimization mathematical model; and establishing a gas reservoir numerical simulation model considering the spatial distribution characteristics and the heterogeneous characteristics of the river channel sand body through the micro-seismic interpretation picture and the logging interpretation data of the river channel sand body of the target gas reservoir. Through fracturing fracture parameter optimization, the cumulative gas production rate is maximized, optimal matching between fracture parameters and sand body distribution is achieved, and effective guidance is provided for efficient development of tight gas reservoirs.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas field development, and particularly relates to a method, system and equipment for optimizing crack parameters of a tight gas reservoir fracturing horizontal well. Background Art

[0002] Tight gas is one of the important areas for unconventional natural gas exploration and development. my country is rich in tight gas resources and has great potential for increasing reserves and production. Accelerating the development and utilization of tight gas will play an important role in improving my country's natural gas self-sufficiency, ensuring national energy security, and achieving the "dual carbon" goals. In 2021, the tight gas production of the Jinqiu Gas Field in Sichuan this year was nearly 200 million cubic meters, which is four times the annual production of tight gas last year, and is steadily moving towards the annual production target of 340 million cubic meters. Compared with conventional natural gas, tight gas refers to natural gas produced in sandstone reservoirs with extremely low porosity and permeability. The tight gas reservoirs in the Jinqiu Gas Field in the Sichuan Basin are highly heterogeneous, with small effective sand bodies, mostly controlled by river sand bodies, and are very difficult to develop. Therefore, it is of great significance to establish a method for optimizing fracture parameters of horizontal wells in the fracturing of tight gas reservoirs with heterogeneous river sand bodies, provide technical support for the efficient development of tight gas in the Jinqiu Gas Field in the Sichuan Basin, and realize the construction of a "natural gas Daqing" in the Sichuan-Chongqing region.

[0003] At present, domestic and foreign scholars have widely used optimization technology combining numerical simulation methods with intelligent optimization algorithms to conduct research on the optimization of fracture parameters of fracturing horizontal wells. This type of technology is usually based on optimization theory, with economic net present value or maximum oil and gas production as the optimization target, and the number of fractures, location, conductivity, and half-fracture length as optimization variables. Considering the constraints affected by the current fracturing process, it continuously iterates and optimizes according to the optimization algorithm's own optimization mechanism, and finally gives the optimal fracture parameters. Compared with single-factor sensitivity analysis to find inflection points or orthogonal experimental design to select the best solution, the optimization technology based on intelligent optimization algorithm has higher solution efficiency and more accurate optimal solution. However, the current intelligent optimization technology for fracture parameters of tight gas reservoirs is mostly aimed at regular rectangular gas reservoirs, and lacks consideration of the distribution characteristics of river channel sand bodies. In addition, the consideration of reservoir heterogeneity is mostly based on the existing heterogeneous porosity, permeability, and saturation distribution field data. Therefore, if there is no existing heterogeneous physical property distribution field data, it is difficult for the existing method to consider the influence of heterogeneous characteristics on fracture parameters. Summary of the invention

[0004] In view of the above problems, the present invention proposes a method for optimizing fracture parameters of a horizontal well in a tight gas reservoir, the method comprising:

[0005] Determine the spatial distribution model of river channel sand bodies based on geological parameters;

[0006] Determine the channel sand body heterogeneity attribute model based on horizontal wellbore parameters and channel sand body spatial distribution model;

[0007] Determine a numerical simulation model of an actual gas reservoir of a heterogeneous channel sand body according to simulated production performance determined by horizontal wellbore parameters, working system parameters and a channel sand body heterogeneous attribute model and actual production performance corresponding to the parameters;

[0008] Determine the mathematical model for optimizing fracture parameters of heterogeneous channel sand bodies;

[0009] The mathematical model for optimizing fracture parameters of heterogeneous channel sand bodies is solved by using the optimization algorithm and the actual numerical simulation model of heterogeneous channel sand bodies in gas reservoirs, and the optimization method for fracture parameters of horizontal wells in tight gas reservoirs is determined.

[0010] Further, the geological parameters include microseismic interpretation images of river channel sand bodies;

[0011] The horizontal wellbore parameters include permeability, porosity, gas saturation data interpreted by well logging and hydraulic fracturing microseismic data;

[0012] The working system parameters include a curve of bottom hole flow pressure changing with time;

[0013] The actual production dynamics include the curves of daily water production and daily gas production changing with time.

[0014] Further, determining the spatial distribution model of the river channel sand body according to the geological parameters includes:

[0015] Determine the horizontal and vertical grid numbers of the target gas reservoir numerical simulation model, and change the pixel number of the microseismic interpretation picture of the channel sand body according to the grid number;

[0016] Identify each pixel point of the modified channel sand body microseismic interpretation image as the mixing ratio of three primary colors;

[0017] The grayscale field image of the microseismic interpretation picture of the channel sand body is obtained according to the mixing ratio of the three primary colors identified at each pixel point;

[0018] Determine a binary image of a microseismic interpretation picture of a channel sand body according to the gray field image;

[0019] The spatial distribution model of the channel sand body is determined according to the binary image.

[0020] Furthermore, the channel sand body heterogeneity attribute model is determined based on the horizontal wellbore parameters and the channel sand body spatial distribution model, including:

[0021] According to the position of the horizontal wellbore in the microseismic interpretation image of the river channel sand body, the position coordinates of the numerical discrete points of the horizontal wellbore are determined;

[0022] Determining the well logging interpretation data corresponding to the discrete points according to the length of the horizontal section of the horizontal wellbore and the corresponding well logging interpretation data;

[0023] Interpolating and discretizing the heterogeneous attribute distribution field of the target gas reservoir according to the well logging interpretation data corresponding to the discrete points;

[0024] The heterogeneous attribute distribution field is assigned to the spatial distribution model of the channel sand body, and the porosity, permeability and gas saturation of the position grid are assigned according to the grid validity of the corresponding position to determine the channel sand body heterogeneous attribute model.

[0025] Further, the numerical simulation model of the actual gas reservoir of the heterogeneous channel sand body is determined according to the simulated production performance determined by the horizontal wellbore parameters, the working system parameters and the channel sand body heterogeneous attribute model and the actual production performance corresponding to the parameters, including:

[0026] Assign hydraulic fracturing microseismic data to the channel sand body heterogeneous attribute model to establish the target gas reservoir basic model;

[0027] Assigning initial gas-water property parameters, fracturing crack parameters and bottom hole flow pressure change curve to the target gas reservoir basic model to establish a target gas reservoir numerical simulation model;

[0028] Obtaining the production performance of the numerical simulation model of the target gas reservoir, wherein the production performance includes a curve of daily water production and daily gas production varying with time;

[0029] The gas-water property parameters and the fracturing crack parameters are adjusted until the production performance of the obtained numerical simulation model of the target gas reservoir is consistent with the actual production performance, and the actual gas reservoir numerical simulation model of the heterogeneous channel sand body is determined.

[0030] Furthermore, the mathematical model for optimizing fracture parameters of heterogeneous channel sand bodies includes:

[0031] According to the cumulative gas production of fracturing crack parameters, the optimization objective function of fracturing crack parameters is established, and the mathematical model for optimizing fracture parameters of heterogeneous river sand bodies is determined.

[0032] Furthermore, the optimization objective function of the fracturing crack parameters is expressed as:

[0033]

[0034]

[0035] Among them, u * represents the optimal crack parameter after optimization, u m represents the hydraulic fracture parameters, U represents the feasible domain of the hydraulic fracture parameters, J(u m ) represents the fracture parameter u m The cumulative gas production, N t represents the total number of time steps, n represents the nth time step, Δt nIndicates the step size of the nth time step, N stage represents the total number of fracturing stages in the horizontal well, j represents the jth fracture, It represents the average daily gas production of the j-th fracture at the n-th time step.

[0036] Furthermore, the mathematical model for optimizing fracture parameters of heterogeneous channel sand bodies is solved by using the optimization algorithm and the numerical simulation model of the actual gas reservoir of heterogeneous channel sand bodies, and the optimization method for fracture parameters of horizontal wells in tight gas reservoirs is determined to include:

[0037] Extracting a first solution in a feasible domain of fracturing fracture parameters by an optimization algorithm;

[0038] Assigning the first scheme to the actual gas reservoir numerical simulation model of the heterogeneous channel sand body to obtain the daily gas production corresponding to the first scheme;

[0039] Determining the objective function of the first scheme according to the daily gas production corresponding to the first scheme;

[0040] The first scheme and the objective function corresponding to the first scheme are input into the optimization algorithm for looping until the optimization process reaches a convergence condition, and the second scheme and the objective function corresponding to the second scheme that meet the convergence condition are output.

[0041] Furthermore, the convergence condition includes:

[0042] When the number of iterations reaches a first preset value, and / or the number of times the actual gas reservoir numerical simulation model of the heterogeneous channel sand body is called reaches a second preset value, and / or when the second scheme is updated, the difference between the second scheme and the first scheme is less than a third preset value.

[0043] The present invention also provides a system for optimizing fracture parameters of a tight gas reservoir fractured horizontal well, the system comprising a first determining unit, a second determining unit, a third determining unit, a fourth determining unit and a parameter optimization unit.

[0044] The first determination unit is used to determine the spatial distribution model of the river channel sand body according to the geological parameters;

[0045] The second determination unit is used to determine the channel sand body heterogeneity attribute model according to the horizontal wellbore parameters and the channel sand body spatial distribution model;

[0046] The third determination unit is used to determine the numerical simulation model of the actual gas reservoir of the heterogeneous river channel sand body according to the simulated production performance determined by the horizontal wellbore parameters, the working system parameters and the river channel sand body heterogeneous attribute model and the actual production performance corresponding to the parameters;

[0047] The fourth determination unit is used to determine the mathematical model for optimizing fracture parameters of the heterogeneous river channel sand body;

[0048] The parameter optimization unit is used to solve the mathematical model for optimizing fracture parameters of heterogeneous channel sand bodies through optimization algorithms and actual numerical simulation models of heterogeneous channel sand bodies in gas reservoirs, and determine the method for optimizing fracture parameters of horizontal wells in tight gas reservoirs.

[0049] Further, the geological parameters include microseismic interpretation images of river channel sand bodies;

[0050] The horizontal wellbore parameters include permeability, porosity, gas saturation data interpreted by well logging and hydraulic fracturing microseismic data;

[0051] The working system parameters include a curve of bottom hole flow pressure changing with time;

[0052] The actual production dynamics include the curves of daily water production and daily gas production changing with time.

[0053] Furthermore, the first determination unit includes a modification module, a ratio determination module, a gray field module, a binarization module and a first determination module.

[0054] A modification module is used to determine the number of horizontal and vertical grids of the target gas reservoir numerical simulation model, and to modify the number of pixel points of the microseismic interpretation image of the channel sand body according to the number of grids;

[0055] A ratio determination module, used for identifying each pixel point of the modified channel sand body microseismic interpretation image as a mixing ratio of three primary colors;

[0056] Gray field module, used to obtain the gray field image of the microseismic interpretation picture of the river sand body according to the mixing ratio of the three primary colors identified at each pixel point;

[0057] A binarization module, used for determining a binarized image of a microseismic interpretation picture of a channel sand body according to the gray field image;

[0058] The first determination module is used to determine the spatial distribution model of the river channel sand body according to the binary image.

[0059] Further, the second determination unit includes a coordinate determination module, a data determination module, a distribution field determination module and a second determination module.

[0060] A coordinate determination module is used to determine the position coordinates of the numerical discrete points of the horizontal wellbore according to the position of the horizontal wellbore in the microseismic interpretation picture of the river channel sand body;

[0061] A data determination module, used to determine the well logging interpretation data corresponding to the discrete point according to the length of the horizontal section of the horizontal wellbore and the corresponding well logging interpretation data;

[0062] A distribution field determination module is used to interpolate and discretize the heterogeneous attribute distribution field of the target gas reservoir according to the well logging interpretation data corresponding to the discrete points;

[0063] The second determination module is used to assign the heterogeneous attribute distribution field to the channel sand body spatial distribution model, assign the porosity, permeability and gas saturation of the position grid according to the grid validity of the corresponding position, and determine the channel sand body heterogeneous attribute model.

[0064] Further, the third determination unit includes a basic determination module, a simulation determination module, a dynamic determination module and a third determination module.

[0065] The basic determination module is used to assign hydraulic fracturing microseismic data to the channel sand body heterogeneous attribute model to establish the target gas reservoir basic model;

[0066] A simulation determination module is used to assign initial gas-water property parameters, fracturing crack parameters and bottom hole flow pressure change curve to the target gas reservoir basic model to establish a target gas reservoir numerical simulation model;

[0067] A dynamic determination module is used to obtain the production dynamics of the target gas reservoir numerical simulation model, wherein the production dynamics include the curves of daily water production and daily gas production changing with time;

[0068] The third determination module is used to adjust the gas-water attribute parameters and the fracturing crack parameters until the production performance of the obtained target gas reservoir numerical simulation model is consistent with the actual production performance, and determine the actual gas reservoir numerical simulation model of the heterogeneous channel sand body.

[0069] Furthermore, the fourth determination unit is used to establish an optimization objective function of the hydraulic fracture parameters according to the cumulative gas production of the hydraulic fracture parameters, and determine a mathematical model for optimizing the fracture parameters of the heterogeneous river sand body.

[0070] Furthermore, the optimization objective function of the fracturing crack parameters is expressed as:

[0071]

[0072]

[0073] Among them, u * represents the optimal crack parameter after optimization, u m represents the hydraulic fracture parameters, U represents the feasible domain of the hydraulic fracture parameters, J(u m ) represents the fracture parameter u m The cumulative gas production, N t represents the total number of time steps, n represents the nth time step, Δt n Indicates the step size of the nth time step, N stage represents the total number of fracturing stages in the horizontal well, j represents the jth fracture, It represents the average daily gas production of the j-th fracture at the n-th time step.

[0074] Further, the parameter optimization unit includes an extraction module, a gas volume determination module, a function determination module and an output module;

[0075] An extraction module, used for extracting a first solution in a feasible domain of fracturing fracture parameters by using an optimization algorithm;

[0076] A gas volume determination module, used for assigning the first scheme to the actual gas reservoir numerical simulation model of the heterogeneous river channel sand body to obtain the daily gas production corresponding to the first scheme;

[0077] A function determination module, configured to determine an objective function of the first scheme according to a daily gas production corresponding to the first scheme;

[0078] The output module is used to input the first scheme and the objective function corresponding to the first scheme into the optimization algorithm for looping until the optimization process reaches the convergence condition, and output the second scheme that meets the convergence condition and the objective function corresponding to the second scheme.

[0079] Furthermore, the convergence condition includes:

[0080] When the number of iterations reaches a first preset value, and / or the number of times the actual gas reservoir numerical simulation model of the heterogeneous channel sand body is called reaches a second preset value, and / or when the second scheme is updated, the difference between the second scheme and the first scheme is less than a third preset value.

[0081] The present invention also provides a device for optimizing fracture parameters of a tight gas reservoir fractured horizontal well, the device comprising at least one processor and at least one memory, the memory being electrically connected to the processor, wherein:

[0082] The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method for optimizing fracture parameters of horizontal wells in tight gas reservoir fracturing described in the present invention.

[0083] The method, system and equipment for optimizing fracture parameters of horizontal wells in tight gas reservoirs of the present invention establish a gas reservoir numerical simulation model that takes into account the spatial distribution characteristics and heterogeneous characteristics of the channel sand bodies through microseismic interpretation images and well logging interpretation data of the channel sand bodies of the target gas reservoir. By optimizing the fracture parameters of the fracturing, the cumulative gas production is maximized, and the best match between the fracture parameters and the sand body distribution is achieved, providing effective guidance for the efficient development of tight gas reservoirs.

[0084] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0086] Figure 1 A schematic diagram of the process flow of a method for optimizing fracture parameters of a horizontal well in a tight gas reservoir under fracturing in an embodiment of the present invention is shown;

[0087] Figure 2 A grayscale image of microseismic interpretation of a channel sand body in an embodiment of the present invention is shown;

[0088] Figure 3 A binarization diagram of microseismic interpretation of a channel sand body in an embodiment of the present invention is shown;

[0089] Figure 4 A diagram showing the spatial distribution model of the river channel sand body in an embodiment of the present invention is shown;

[0090] Figure 5 A schematic diagram of well logging interpretation data for a horizontal section of a horizontal well in an embodiment of the present invention is shown;

[0091] Figure 6 The porosity distribution field diagram of the river channel sand body in the embodiment of the present invention is shown;

[0092] Figure 7 The permeability distribution field diagram of the river channel sand body in the embodiment of the present invention is shown;

[0093] Figure 8 A basic model diagram of a target gas reservoir for introducing hydraulic fractures in an embodiment of the present invention is shown;

[0094] Fig. 9 The target gas reservoir numerical simulation model for importing porosity and permeability in an embodiment of the present invention is shown, wherein (a) is its porosity attribute and (b) is its permeability attribute;

[0095] Fig.10 A schematic diagram showing an actual daily gas production curve of a target well and a daily gas production curve obtained by numerical simulation fitting calculation in an example of the present invention is shown;

[0096] Fig.11A flow chart for solving optimization variables in an embodiment of the present invention is shown;

[0097] Fig.12 A dynamic change curve diagram of the optimization of the objective function according to the change of the number of predictions in an embodiment of the present invention is shown;

[0098] Fig.13 A schematic diagram of the optimal crack spacing obtained by optimization in an embodiment of the present invention is shown;

[0099] Fig.14 A schematic diagram of the optimal crack half-length obtained by optimization in an embodiment of the present invention is shown;

[0100] Fig.15 A schematic diagram of the optimal fracture conductivity obtained by optimization in an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0101] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0102] The present invention provides a method, system and equipment for optimizing fracture parameters of a horizontal well in a tight gas reservoir, so as to solve the problem that the existing fracture parameter optimization method considers reservoir characteristics too ideally. If there is no existing heterogeneous physical property distribution field data, it is difficult to consider the influence of the spatial distribution characteristics of heterogeneous river channel sand bodies on the fracture parameters.

[0103] In the embodiment of the present invention, Figure 1 The figure shows a schematic flow chart of a method for optimizing fracture parameters of a horizontal well in a tight gas reservoir under fracturing according to an embodiment of the present invention. Figure 1 The methods include:

[0104] S1. Determine the spatial distribution model of river sand bodies based on geological parameters;

[0105] S2. Determine the channel sand body heterogeneity attribute model based on the horizontal wellbore parameters and the channel sand body spatial distribution model;

[0106] S3, determining a numerical simulation model of an actual gas reservoir of a heterogeneous channel sand body according to the simulated production performance determined by the horizontal wellbore parameters, the working system parameters and the channel sand body heterogeneous attribute model and the actual production performance corresponding to the parameters;

[0107] S4. Determine the mathematical model for optimizing fracture parameters of heterogeneous river channel sand bodies;

[0108] S5. The mathematical model for optimizing fracture parameters of heterogeneous channel sand bodies is solved by using the optimization algorithm and the numerical simulation model of the actual gas reservoir of heterogeneous channel sand bodies, and the optimization method for fracture parameters of horizontal wells in tight gas reservoirs is determined.

[0109] In an embodiment of the present invention, before determining the spatial distribution model of the channel sand body, the step of collecting basic data of the target reservoir is also included. The target energy storage basic data in the embodiment of the present invention include geological parameters, horizontal wellbore parameters, working system parameters and actual production dynamics corresponding to the geological parameters, horizontal wellbore parameters and working system parameters; the geological parameters include microseismic interpretation pictures of the channel sand body; the horizontal wellbore parameters include permeability, porosity, gas saturation data and hydraulic fracturing microseismic data interpreted by well logging; the working system parameters include the bottom hole pressure change curve over time; the actual production dynamics include the daily water production and daily gas production change curves over time.

[0110] In the embodiment of the present invention, the target energy storage basic data is described in detail with reference to the relevant drawings. Figure 2 shows a grayscale image of the microseismic interpretation of the channel sand body in an embodiment of the present invention, Figure 2 In the experiment, the original formation pressure was 25 MPa and the surface temperature was 80°C. Figure 5 The schematic diagram of logging interpretation data of the horizontal section of a horizontal well in an embodiment of the present invention is shown. In the embodiment of the present invention, the working system parameter is that the bottom hole flowing pressure is constant at 18MPa. The actual production dynamics include the daily water production and daily gas production variation curves over time. In the embodiment of the present invention, the actual production dynamics daily gas production variation curve over time is also described in detail. Fig.10 The figure shows a schematic diagram of the actual daily gas production curve of the target well and the daily gas production curve obtained by numerical simulation fitting calculation in the embodiment of the present invention. Fig.10 In the figure, the horizontal axis represents time / day, and the vertical axis represents daily gas production. 4 m 3 / day. The actual production data of the target well and the production data calculated by numerical simulation are fitted to obtain the daily gas production curve. The daily gas production increases with the number of days and increases from about 20×10 4 m 3 / day decreased to about 2.5×10 4 m 3 / day. In the daily gas production curve, the decline is the largest within 50 days, the decline tends to be gentle within 50-150 days, and the decline is relatively slow within 150 to about 365 days.

[0111] In the embodiment of the present invention, the step of determining the spatial distribution model of the river channel sand body according to the geological parameters in step S1 is also specifically described:

[0112] S101, given that the number of grids in the x and y directions of the numerical simulation model of the target gas reservoir is 162 and 142 respectively, the number of pixel points of the microseismic interpretation image of the channel sand body is changed to 162 and 142;

[0113] S102, identifying each pixel point of the microseismic interpretation image of the river channel sand body after pixel modification as a mixed ratio of the three primary colors of red, green and blue;

[0114] S103, converting the three primary color mixing ratio of each pixel point into a grayscale value to obtain a grayscale field image of the microseismic interpretation picture of the river channel sand body, such as Figure 2 As shown, Figure 2 In the figure, the hydraulic fracturing crack position and length of the Qiulin 206-5-H1 evaluation well are shown. The model of the evaluation well in the figure is only an example, and the change of the evaluation well type is also within the protection scope of the present invention;

[0115] S104, marking pixels with grayscale values ​​in the grayscale field map as 1, and marking pixels without grayscale values ​​as 0, to obtain a binary image of the microseismic interpretation picture of the channel sand body, such as Figure 3 As shown, Figure 3 In the image, pixels marked as 1 represent white, and pixels marked as 0 represent black;

[0116] S105. Based on the binarized image of the microseismic interpretation picture of the channel sand body, the grids with a value of 1 are recorded as valid grids, and the grids with a value of 0 are recorded as invalid grids, and a spatial distribution model of the channel sand body is constructed, such as Figure 4 As shown, Figure 4 In the model, the channel sand body is displayed in a space with a height of 1, a length of 150, and a width of 200 respectively. In the embodiment of the present invention, there is no specific limitation on the unit of the model. During actual operation, the unit of the model in the present invention can be adaptively changed according to actual needs.

[0117] Step S2 determines the channel sand body heterogeneity attribute model according to the horizontal wellbore parameters and the channel sand body spatial distribution model, and specifically includes:

[0118] S201, discretizing the horizontal wellbore values ​​into 87 points, and obtaining the position coordinates of the 87 points based on the coordinate positions of the horizontal wellbore in the microseismic interpretation image of the river channel sand body;

[0119] S202, based on the length of the horizontal section of the horizontal wellbore and its corresponding logging interpretation data, such as Figure 5 As shown in the figure, the logging interpretation data corresponding to 87 locations are obtained, including porosity, permeability, Figure 5 In the well logging interpretation data, the formation depth, lithology profile, drilling display, porosity, sand quality, mud quality, collar, perforation position, amplitude, etc. are also included for exemplary description;

[0120] S203. Based on the logging interpretation data corresponding to the m position points, an interpolation method is used to interpolate and discretize the heterogeneous attribute distribution field of the target gas reservoir, where the distribution field includes a porosity distribution field, a permeability distribution field, and a gas saturation field. In the embodiment of the present invention, the interpolation method includes but is not limited to Kriging interpolation, Gaussian interpolation and other methods. Without departing from the technical concept of the present invention, changes to the interpolation method are also within the protection scope of the present invention. Figure 6 The porosity distribution field diagram of the river channel sand body in the embodiment of the present invention is shown. Figure 6 In the figure, higher porosity shows shallower depth; Figure 7 The permeability distribution field diagram of the river sand body in the embodiment of the present invention is shown. Figure 7 In the figure, the unit of permeability is expressed in mD. The higher the permeability, the shallower the depth in the model;

[0121] S204, assigning the heterogeneous attribute distribution field to the spatial distribution model of the channel sand body constructed in step S105, if the corresponding position is a valid grid, assigning the porosity, permeability, and gas saturation at the position to the grid at the position; if the corresponding position is an invalid grid, the porosity, permeability, and gas saturation of the grid at the position are all assigned to zero, thereby constructing a heterogeneous attribute model of the channel sand body;

[0122] Step S3 determines the numerical simulation model of the actual gas reservoir of the heterogeneous channel sand body according to the simulated production performance determined by the horizontal wellbore parameters, the working system parameters and the channel sand body heterogeneous attribute model and the actual production performance corresponding to the parameters, and specifically includes:

[0123] S301, based on the microseismic data of hydraulic fracturing of the target well or the adjacent well, the location and length of the hydraulic fracturing cracks are obtained. In the embodiment of the present invention, Figure 2 The location and length of hydraulic fracturing cracks are obtained from the grayscale image of the microseismic interpretation of the river sand body. In the embodiment of the present invention, the microseismic data points of each level of fracturing are selected to determine the location and length of the cracks step by step. For each level of cracks, these data points are framed by a rectangle with the smallest area. At this time, the length of the long side of the rectangle is regarded as the crack length of the fracturing section of this level. The intersection point of the center line of the rectangle and the horizontal wellbore is regarded as the location of the crack of this level. The obtained location and length of the fracturing cracks are imported into the sand body heterogeneous attribute model established in step S204 to establish the basic model of the target gas reservoir. Figure 8 The figure shows the basic model diagram of the target gas reservoir in which the hydraulic fracture is introduced in the embodiment of the present invention. Figure 8 In the figure, the hydraulic fracture Wall-1 is shown in the middle of the model;

[0124] S302, manually set initial gas-water attribute parameters, including relative permeability curve, capillary force curve, gas-water density, viscosity and pressure variation relationship, manually set initial fracturing crack parameters, including crack aperture and crack permeability, assign gas-water attribute parameters, fracturing crack parameters and bottom hole flow pressure variation curve to the target gas reservoir basic model established in step S301, and establish a target gas reservoir numerical simulation model, Fig. 9 The target gas reservoir numerical simulation model for importing porosity and permeability in an embodiment of the present invention is shown, wherein (a) is its porosity attribute and (b) is its permeability attribute. Fig. 9 In (a), around the hydraulic fracture, the porosity ranges from 0.000 to 0.173. In this range, the porosity depth in the model shows a trend of gradually becoming shallower and then gradually becoming deeper; Fig. 9 In (a), around the hydraulic fracture, the permeability ranges from 0.00 to 0.80 mD. In this range, the permeability in the model gradually becomes shallower and then gradually becomes deeper;

[0125] S303, obtaining the production dynamics of the numerical simulation model of the target gas reservoir including the daily water production and daily gas production versus time curves through numerical solution;

[0126] S304, by continuously adjusting the gas-water property parameters and the fracturing crack parameters of step S302, the production performance calculated by the numerical simulation model of the target gas reservoir is consistent with the actual production performance, such as Fig.10 As shown, when the error is less than 5%, the adjustment is stopped. At this time, the numerical simulation model of the actual gas reservoir of the heterogeneous river sand body is established; at the same time, the reservoir parameters obtained by fitting are shown in Table 1:

[0127] Table 1. Physical property parameters of tight gas reservoirs obtained by fitting in specific embodiments

[0128]

[0129]

[0130] In Table 1, the physical property parameters of tight gas reservoirs include physical property parameters of tight gas reservoirs, compressibility coefficient of water phase, gas phase viscosity and water phase viscosity. In the embodiments of the present invention, examples are given for the selection of the units and values ​​of the parameters.

[0131] Step S4 determines the mathematical model for optimizing fracture parameters of heterogeneous channel sand bodies, specifically including:

[0132] S401, taking the cumulative gas production as the optimization target, establishing the optimization objective function of the fracturing fracture parameters, as shown in formula (1):

[0133]

[0134]

[0135] In the formula, u * represents the optimal crack parameters obtained after optimization; u m represents the mth group of optimization variables, i.e., the hydraulic fracture parameters; U represents the optimization space where the optimization variables can be selected, i.e., the feasible domain of the hydraulic fracture parameters, J(u m ) represents the fracture parameter u m The cumulative gas production obtained; N t represents the total number of time steps; n represents the nth time step; Δt n Indicates the step length of the nth time step, days; N stage represents the total number of fracturing stages in the horizontal well; j represents the j-th fracture; represents the average daily gas production of the j-th fracture at the n-th time step;

[0136] S402, establishing constraints for optimizing fracturing parameters, as shown in formula (2):

[0137]

[0138] The constraints can be selected as upper and lower limit constraints, that is, each optimization variable is constrained within a reasonable range on the one hand, forming an optimization space U. In the formula, HLi represents the half-length of the i-th level fracture, Si represents the distance between the i-th level fracture and the adjacent fractures, and Ci represents the conductivity of the i-th level fracture. On the other hand, the constraints must satisfy the equality constraints, including the sum HLf of the half-length HLi of the fracture as a constant value const1, that is, the amount of fracturing fluid is constant, and the total length of the fracture to be transformed is considered to be a constant. In the embodiment of the present invention, the total half-length of the fracture is selected as a constant of 1650m, and the sum Sf of the fracture spacing Si is a constant value const2. It is considered that the horizontal well has been drilled and the length of the horizontal section is a constant. In the embodiment of the present invention, the length of the horizontal section is a constant of 660m. The sum Cf of the fracture conductivity Ci is a constant value const3. It is considered that the amount of proppant used during fracturing is constant, and the sum of the fracture conductivity during transformation is a constant. In the embodiment of the present invention, the sum of the fracture conductivity during transformation is a constant of 88D·cm;

[0139] Step S5 solves the mathematical model for optimizing fracture parameters of heterogeneous channel sand bodies by using the optimization algorithm and the numerical simulation model of the actual gas reservoir of heterogeneous channel sand bodies, and determines the method for optimizing fracture parameters of horizontal wells in tight gas reservoirs by fracturing. Specifically, the method includes:

[0140] S501, Fig.11 FIG. 4 shows a flow chart of solving the optimization variables in an embodiment of the present invention. Fig.11 In the optimization process, an intelligent optimization algorithm is used to sample and generate the initial solution u in the optimization space U. 0 , the variable u 0Substitute the actual gas reservoir numerical simulation model of the heterogeneous channel sand body established in step S3 to obtain the variable u 0 The corresponding daily gas production is calculated using the objective function calculation formula established in step S401 to obtain the objective function value J(u 0 );

[0141] S502, (u 0 ,J(u 0 )) Input the intelligent optimization algorithm, which starts to search for the best solution according to its own optimization mechanism and determines whether the optimization process meets the convergence condition. If not, it outputs the variable u of the new solution. i , the variable u i Substitute the actual gas reservoir numerical simulation model of the heterogeneous channel sand body established in step S4 to obtain the variable u i The corresponding objective function value J(u i ). Will (u i ,J(u i )) Input the intelligent optimization algorithm, and the intelligent optimization algorithm continues to search for the best solution. If the convergence condition is met, the search stops and the optimal solution u is output * , and the objective function value J(u * );

[0142] The convergence conditions include the number of iterations reaching a certain preset value, the number of times the numerical simulation model of the actual gas reservoir of the heterogeneous channel sand body is called reaching a certain preset value, and the update of the variable u i When i with u i-1 The difference is less than a preset value, etc. In the embodiment of the present invention, the convergence condition is selected as calling the actual gas reservoir numerical simulation model of the heterogeneous channel sand body for 1000 times.

[0143] Optionally, the intelligent optimization algorithm can be: gradient algorithm, such as steepest descent method, quasi-Newton method, trust region method, etc.; stochastic gradient approximation method, such as random perturbation approximation algorithm, set-based optimization algorithm, random simple approximate gradient algorithm, etc.; analytical derivative method, such as direct method and adjoint method; evolution-based gradient-free algorithm, such as genetic algorithm, evolutionary strategy, differential evolution algorithm; physics-based gradient-free algorithm, such as simulated annealing, gravity search algorithm, etc.; population-based gradient-free algorithm, such as particle swarm optimization, whale group algorithm, etc.; deterministic gradient-free algorithm, such as Newton method, steepest descent method, multi-level coordinated search algorithm, pattern search method, etc.; random gradient-free algorithm, such as genetic algorithm, particle swarm algorithm, etc.; local search gradient-free algorithm, such as pattern search algorithm, simplex method, etc.; global search gradient-free algorithm, such as differential evolution, proxy optimization algorithm, etc. The present invention is not limited to this.

[0144] The above-mentioned fracture parameter optimization design method can establish a gas reservoir numerical simulation model that takes into account the spatial distribution characteristics of the channel sand body and its heterogeneous characteristics through the microseismic interpretation images and logging interpretation data of the channel sand body of the target gas reservoir. By optimizing the fracturing fracture parameters, the cumulative gas production is maximized, and the best match between the fracture parameters and the sand body distribution is achieved, providing effective guidance for the efficient development of tight gas reservoirs. Traditional optimization design methods are mostly based on rectangular oil and gas reservoir models for optimization, and cannot consider the reasonable match between the spatial distribution characteristics of the channel sand body and the fracture parameters. In addition, the heterogeneous physical property parameters (permeability, porosity, saturation field) are mostly used as known data, which is not suitable for the situation where there is a lack of physical property parameter fields.

[0145] In the embodiment of the present invention, the intelligent optimization algorithm selects a genetic algorithm. Fig.12 The following is a graph showing the dynamic change of the objective function in the embodiment of the present invention as the number of predictions changes. Fig.12 In the figure, the horizontal axis represents the cumulative gas production, 10 7 m 3 , the vertical axis represents the number of simulations. As the number of simulations increases, the number of simulations in the embodiment of the present invention exceeds 700 times. The objective function is 7 m 3 Approaching the optimum.

[0146] In the embodiment of the present invention, the optimal fracture spacing between fractures, the optimal half fracture length of each fracture, and the optimal fracture conductivity obtained by optimization are also explained after the objective function changes with the number of simulations. Fig.13 FIG. 4 shows a schematic diagram of the optimal crack spacing obtained by optimization in an embodiment of the present invention, Fig.13 In the figure, the horizontal axis represents the crack number and the vertical axis represents the crack segment spacing, m. In the figure, when the cracks are numbered 1 and 5, the crack segment spacing is 75m, when the cracks are numbered 3, 4, and 6, the crack segment spacing is 90m, when the cracks are numbered 2, 7, and 9, the crack segment spacing is 60m, when the crack is numbered 8, the crack segment spacing is 45m, and when the crack is numbered 10, the crack segment spacing is 15m.

[0147] Fig.14 FIG. 4 shows a schematic diagram of the optimal crack half-length obtained by optimization in an embodiment of the present invention, Fig.14 In the figure, the horizontal axis represents the crack number and the vertical axis represents the half-crack length, in m. In the figure, when the crack numbers are 1, 3, 4, and 11, the half-crack length is about 200 m; when the crack number is 9, the half-crack length is about 160 m; when the crack number is 6, the half-crack length is about 150 m; when the crack number is 10, the half-crack length is about 120 m; when the crack number is 7, the half-crack length is about 112 m; when the crack number is 8, the half-crack length is about 108 m; when the crack number is 5, the half-crack length is about 103 m; when the crack number is 2, the half-crack length is about 100 m.

[0148] Fig.15 FIG. 4 is a schematic diagram showing the optimal fracture conductivity obtained by optimization in an embodiment of the present invention. Fig.15 In the figure, the abscissa represents the crack number, and the ordinate represents the conductivity, D·cm. In the figure, when the crack is numbered 1, the conductivity is about 11.2D·cm, when the cracks are numbered 4 and 11, the conductivity is about 10.8D·cm, when the crack is numbered 9, the conductivity is about 10.5D·cm, when the crack is numbered 6, the conductivity is about 9.1D·cm, when the crack is numbered 3, the conductivity is about 9D·cm, when the crack is numbered 8, the conductivity is about 6.7D·cm, when the crack is numbered 7, the conductivity is about 6D·cm, when the crack is numbered 2, the conductivity is about 5.2D·cm, and when the cracks are numbered 5 and 10, the conductivity is about 4.5D·cm.

[0149] In an embodiment of the present invention, a system for optimizing fracture parameters of a tight gas reservoir fractured horizontal well is also provided. The system includes a first determining unit, a second determining unit, a third determining unit, a fourth determining unit and a parameter optimizing unit.

[0150] The first determination unit is used to determine the spatial distribution model of the river channel sand body according to the geological parameters;

[0151] The second determination unit is used to determine the channel sand body heterogeneity attribute model according to the horizontal wellbore parameters and the channel sand body spatial distribution model;

[0152] The third determination unit is used to determine the numerical simulation model of the actual gas reservoir of the heterogeneous river channel sand body according to the simulated production performance determined by the horizontal wellbore parameters, the working system parameters and the river channel sand body heterogeneous attribute model and the actual production performance corresponding to the parameters;

[0153] The fourth determination unit is used to determine the mathematical model for optimizing fracture parameters of the heterogeneous river channel sand body;

[0154] The parameter optimization unit is used to solve the mathematical model for optimizing fracture parameters of heterogeneous channel sand bodies through optimization algorithms and actual numerical simulation models of heterogeneous channel sand bodies in gas reservoirs, and determine the method for optimizing fracture parameters of horizontal wells in tight gas reservoirs.

[0155] Specifically, the geological parameters include microseismic interpretation images of river channel sand bodies;

[0156] The horizontal wellbore parameters include permeability, porosity, gas saturation data interpreted by well logging and hydraulic fracturing microseismic data;

[0157] The working system parameters include a curve of bottom hole flow pressure changing with time;

[0158] The actual production dynamics include the curves of daily water production and daily gas production changing with time.

[0159] Specifically, the first determination unit includes a modification module, a ratio determination module, a gray field module, a binarization module and a first determination module.

[0160] A modification module is used to determine the number of horizontal and vertical grids of the target gas reservoir numerical simulation model, and to modify the number of pixel points of the microseismic interpretation image of the channel sand body according to the number of grids;

[0161] A ratio determination module, used for identifying each pixel point of the modified channel sand body microseismic interpretation image as a mixing ratio of three primary colors;

[0162] Gray field module, used to obtain the gray field image of the microseismic interpretation picture of the river sand body according to the mixing ratio of the three primary colors identified at each pixel point;

[0163] A binarization module, used for determining a binarized image of a microseismic interpretation picture of a channel sand body according to the gray field image;

[0164] The first determination module is used to determine the spatial distribution model of the river channel sand body according to the binary image.

[0165] Specifically, the second determination unit includes a coordinate determination module, a data determination module, a distribution field determination module and a second determination module.

[0166] A coordinate determination module is used to determine the position coordinates of the numerical discrete points of the horizontal wellbore according to the position of the horizontal wellbore in the microseismic interpretation picture of the river channel sand body;

[0167] A data determination module, used to determine the well logging interpretation data corresponding to the discrete point according to the length of the horizontal section of the horizontal wellbore and the corresponding well logging interpretation data;

[0168] A distribution field determination module is used to interpolate and discretize the heterogeneous attribute distribution field of the target gas reservoir according to the well logging interpretation data corresponding to the discrete points;

[0169] The second determination module is used to assign the heterogeneous attribute distribution field to the channel sand body spatial distribution model, assign the porosity, permeability and gas saturation of the position grid according to the grid validity of the corresponding position, and determine the channel sand body heterogeneous attribute model.

[0170] Specifically, the third determination unit includes a basic determination module, a simulation determination module, a dynamic determination module and a third determination module.

[0171] The basic determination module is used to assign hydraulic fracturing microseismic data to the channel sand body heterogeneous attribute model to establish the target gas reservoir basic model;

[0172] A simulation determination module is used to assign initial gas-water property parameters, fracturing crack parameters and bottom hole flow pressure change curve to the target gas reservoir basic model to establish a target gas reservoir numerical simulation model;

[0173] A dynamic determination module is used to obtain the production dynamics of the target gas reservoir numerical simulation model, wherein the production dynamics include the curves of daily water production and daily gas production changing with time;

[0174] The third determination module is used to adjust the gas-water attribute parameters and the fracturing crack parameters until the production performance of the obtained target gas reservoir numerical simulation model is consistent with the actual production performance, and determine the actual gas reservoir numerical simulation model of the heterogeneous channel sand body.

[0175] Specifically, the fourth determination unit is used to establish an optimization objective function of the hydraulic fracture parameters according to the cumulative gas production of the hydraulic fracture parameters, and determine a mathematical model for optimizing the fracture parameters of the heterogeneous river channel sand body.

[0176] Specifically, the optimization objective function of the fracturing crack parameters is expressed as:

[0177]

[0178]

[0179] Among them, u * represents the optimal crack parameter after optimization, u m represents the hydraulic fracture parameters, U represents the feasible domain of the hydraulic fracture parameters, J(u m ) represents the fracture parameter u m The cumulative gas production, N t represents the total number of time steps, n represents the nth time step, Δt n Indicates the step size of the nth time step, N stage represents the total number of fracturing stages in the horizontal well, j represents the jth fracture, It represents the average daily gas production of the j-th fracture at the n-th time step.

[0180] Specifically, the parameter optimization unit includes an extraction module, a gas volume determination module, a function determination module and an output module;

[0181] An extraction module, used for extracting a first solution in a feasible domain of fracturing fracture parameters by using an optimization algorithm;

[0182] A gas volume determination module, used for assigning the first scheme to the actual gas reservoir numerical simulation model of the heterogeneous river channel sand body to obtain the daily gas production corresponding to the first scheme;

[0183] A function determination module, configured to determine an objective function of the first scheme according to a daily gas production corresponding to the first scheme;

[0184] The output module is used to input the first scheme and the objective function corresponding to the first scheme into the optimization algorithm for looping until the optimization process reaches the convergence condition, and output the second scheme that meets the convergence condition and the objective function corresponding to the second scheme.

[0185] Specifically, the convergence conditions include:

[0186] When the number of iterations reaches a first preset value, and / or the number of times the actual gas reservoir numerical simulation model of the heterogeneous channel sand body is called reaches a second preset value, and / or when the second scheme is updated, the difference between the second scheme and the first scheme is less than a third preset value.

[0187] In an embodiment of the present invention, a device for optimizing fracture parameters of a horizontal well in a tight gas reservoir is also provided. The device comprises at least one processor and at least one memory, wherein the memory is electrically connected to the processor.

[0188] The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method for optimizing fracture parameters of horizontal wells in tight gas reservoir fracturing in an embodiment of the present invention.

[0189] The method, system and equipment for optimizing fracture parameters of horizontal wells in tight gas reservoirs of the present invention establish a gas reservoir numerical simulation model that takes into account the spatial distribution characteristics and heterogeneous characteristics of the channel sand bodies through microseismic interpretation images and well logging interpretation data of the channel sand bodies of the target gas reservoir. By optimizing the fracture parameters of the fracturing, the cumulative gas production is maximized, and the best match between the fracture parameters and the sand body distribution is achieved, providing effective guidance for the efficient development of tight gas reservoirs.

[0190] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for optimizing fracture parameters of a horizontal well in a tight gas reservoir, characterized in that: The method comprises: Determine the spatial distribution model of river channel sand bodies based on geological parameters; Determine the channel sand body heterogeneity attribute model based on horizontal wellbore parameters and channel sand body spatial distribution model; Determine a numerical simulation model of an actual gas reservoir of a heterogeneous channel sand body according to simulated production performance determined by horizontal wellbore parameters, working system parameters and a channel sand body heterogeneous attribute model and actual production performance corresponding to the parameters; Determine the mathematical model for optimizing fracture parameters of heterogeneous channel sand bodies; The mathematical model for optimizing fracture parameters of heterogeneous channel sand bodies is solved by using the optimization algorithm and the actual numerical simulation model of heterogeneous channel sand bodies in gas reservoirs, and the optimization method for fracture parameters of horizontal wells in tight gas reservoirs is determined.

2. The method for optimizing fracture parameters of a horizontal well in a tight gas reservoir according to claim 1, characterized in that: The geological parameters include microseismic interpretation images of river channel sand bodies; The horizontal wellbore parameters include permeability, porosity, gas saturation data interpreted by well logging and hydraulic fracturing microseismic data; The working system parameters include a curve of bottom hole flow pressure changing with time; The actual production dynamics include the curves of daily water production and daily gas production changing with time.

3. The method for optimizing fracture parameters of a horizontal well in a tight gas reservoir according to claim 2, characterized in that: Determining the spatial distribution model of the river channel sand body according to the geological parameters includes: Determine the horizontal and vertical grid numbers of the target gas reservoir numerical simulation model, and change the pixel number of the microseismic interpretation picture of the channel sand body according to the grid number; Identify each pixel point of the modified channel sand body microseismic interpretation image as the mixing ratio of three primary colors; The grayscale field image of the microseismic interpretation picture of the channel sand body is obtained according to the mixing ratio of the three primary colors identified at each pixel point; Determine a binary image of a microseismic interpretation picture of a channel sand body according to the gray field image; The spatial distribution model of the channel sand body is determined according to the binary image.

4. The method for optimizing fracture parameters of a horizontal well in a tight gas reservoir according to claim 2 or 3, characterized in that: The heterogeneous attribute model of the channel sand body is determined based on the horizontal wellbore parameters and the spatial distribution model of the channel sand body, including: According to the position of the horizontal wellbore in the microseismic interpretation image of the river channel sand body, the position coordinates of the numerical discrete points of the horizontal wellbore are determined; Determining the well logging interpretation data corresponding to the discrete points according to the length of the horizontal section of the horizontal wellbore and the corresponding well logging interpretation data; Interpolating and discretizing the heterogeneous attribute distribution field of the target gas reservoir according to the well logging interpretation data corresponding to the discrete points; The heterogeneous attribute distribution field is assigned to the spatial distribution model of the channel sand body, and the porosity, permeability and gas saturation of the position grid are assigned according to the grid validity of the corresponding position to determine the channel sand body heterogeneous attribute model.

5. The method for optimizing fracture parameters of a horizontal well in a tight gas reservoir according to claim 2, characterized in that: According to the horizontal wellbore parameters, working system parameters and the channel sand body heterogeneous attribute model, the simulated production performance and the actual production performance corresponding to the parameters are determined to determine the actual gas reservoir numerical simulation model of the heterogeneous channel sand body, including: Assign hydraulic fracturing microseismic data to the channel sand body heterogeneous attribute model to establish the target gas reservoir basic model; Assigning initial gas-water property parameters, fracturing crack parameters and bottom hole flow pressure change curve to the target gas reservoir basic model to establish a target gas reservoir numerical simulation model; Obtaining the production performance of the numerical simulation model of the target gas reservoir, wherein the production performance includes a curve of daily water production and daily gas production varying with time; The gas-water property parameters and the fracturing crack parameters are adjusted until the production performance of the obtained target gas reservoir numerical simulation model is consistent with the actual production performance, and the actual gas reservoir numerical simulation model of the heterogeneous channel sand body is determined.

6. The method for optimizing fracture parameters of a horizontal well in a tight gas reservoir according to claim 5, characterized in that: The mathematical model for determining the optimization of fracture parameters of heterogeneous channel sand bodies includes: According to the cumulative gas production of fracturing crack parameters, the optimization objective function of fracturing crack parameters is established, and the mathematical model for optimizing fracture parameters of heterogeneous river sand bodies is determined.

7. The method for optimizing fracture parameters of a horizontal well in a tight gas reservoir according to claim 6, characterized in that: The optimization objective function of the fracturing crack parameters is expressed as: Among them, u * represents the optimal crack parameter after optimization, u m represents the hydraulic fracture parameters, U represents the feasible domain of the hydraulic fracture parameters, J(u m ) represents the fracture parameter u m The cumulative gas production, N t represents the total number of time steps, n represents the nth time step, Δt n Indicates the step size of the nth time step, N stage represents the total number of fracturing stages in the horizontal well, j represents the jth fracture, It represents the average daily gas production of the j-th fracture at the n-th time step.

8. The method for optimizing fracture parameters of a horizontal well in a tight gas reservoir according to claim 7, characterized in that: The mathematical model for optimizing fracture parameters of heterogeneous channel sand bodies is solved by using optimization algorithms and numerical simulation models of actual gas reservoirs of heterogeneous channel sand bodies. The optimization method for fracture parameters of horizontal wells in tight gas reservoirs is determined as follows: Extracting a first solution in a feasible domain of fracturing fracture parameters by an optimization algorithm; Assigning the first scheme to the actual gas reservoir numerical simulation model of the heterogeneous channel sand body to obtain the daily gas production corresponding to the first scheme; Determining the objective function of the first scheme according to the daily gas production corresponding to the first scheme; The first scheme and the objective function corresponding to the first scheme are input into the optimization algorithm for looping until the optimization process reaches a convergence condition, and the second scheme and the objective function corresponding to the second scheme that meet the convergence condition are output.

9. The method for optimizing fracture parameters of a horizontal well in a tight gas reservoir according to claim 8, characterized in that: The convergence conditions include: When the number of iterations reaches a first preset value, and / or the number of times the actual gas reservoir numerical simulation model of the heterogeneous channel sand body is called reaches a second preset value, and / or when the second scheme is updated, the difference between the second scheme and the first scheme is less than a third preset value.

10. A system for optimizing fracture parameters of horizontal wells in tight gas reservoir fracturing, characterized in that: The system comprises a first determining unit, a second determining unit, a third determining unit, a fourth determining unit and a parameter optimization unit. The first determination unit is used to determine the spatial distribution model of the river channel sand body according to the geological parameters; The second determination unit is used to determine the channel sand body heterogeneity attribute model according to the horizontal wellbore parameters and the channel sand body spatial distribution model; The third determination unit is used to determine the numerical simulation model of the actual gas reservoir of the heterogeneous river channel sand body according to the simulated production performance determined by the horizontal wellbore parameters, the working system parameters and the river channel sand body heterogeneous attribute model and the actual production performance corresponding to the parameters; The fourth determination unit is used to determine the mathematical model for optimizing fracture parameters of the heterogeneous river channel sand body; The parameter optimization unit is used to solve the mathematical model for optimizing fracture parameters of heterogeneous channel sand bodies through optimization algorithms and actual numerical simulation models of heterogeneous channel sand bodies in gas reservoirs, and determine the method for optimizing fracture parameters of horizontal wells in tight gas reservoirs.

11. The system for optimizing fracture parameters of horizontal wells in tight gas reservoir fracturing according to claim 10, characterized in that: The geological parameters include microseismic interpretation images of river channel sand bodies; The horizontal wellbore parameters include permeability, porosity, gas saturation data interpreted by well logging and hydraulic fracturing microseismic data; The working system parameters include a curve of bottom hole flow pressure changing with time; The actual production dynamics include the curves of daily water production and daily gas production changing with time.

12. The system for optimizing fracture parameters of horizontal wells in tight gas reservoir fracturing according to claim 11, characterized in that: The first determination unit includes a modification module, a ratio determination module, a gray field module, a binarization module and a first determination module. A modification module is used to determine the number of horizontal and vertical grids of the target gas reservoir numerical simulation model, and to modify the number of pixel points of the microseismic interpretation image of the channel sand body according to the number of grids; A ratio determination module, used for identifying each pixel point of the modified channel sand body microseismic interpretation image as a mixing ratio of three primary colors; Gray field module, used to obtain the gray field image of the microseismic interpretation picture of the river sand body according to the mixing ratio of the three primary colors identified at each pixel point; A binarization module, used for determining a binarized image of a microseismic interpretation picture of a channel sand body according to the gray field image; The first determination module is used to determine the spatial distribution model of the river channel sand body according to the binary image.

13. The system for optimizing fracture parameters of horizontal wells in tight gas reservoir fracturing according to claim 11 or 12, characterized in that: The second determination unit includes a coordinate determination module, a data determination module, a distribution field determination module, and a second determination module. A coordinate determination module is used to determine the position coordinates of the numerical discrete points of the horizontal wellbore according to the position of the horizontal wellbore in the microseismic interpretation picture of the river channel sand body; A data determination module, used to determine the well logging interpretation data corresponding to the discrete point according to the length of the horizontal section of the horizontal wellbore and the corresponding well logging interpretation data; A distribution field determination module is used to interpolate and discretize the heterogeneous attribute distribution field of the target gas reservoir according to the well logging interpretation data corresponding to the discrete points; The second determination module is used to assign the heterogeneous attribute distribution field to the channel sand body spatial distribution model, assign the porosity, permeability and gas saturation of the position grid according to the grid validity of the corresponding position, and determine the channel sand body heterogeneous attribute model.

14. The system for optimizing fracture parameters of tight gas reservoir horizontal wells according to claim 11, characterized in that: The third determination unit includes a basic determination module, a simulation determination module, a dynamic determination module and a third determination module. The basic determination module is used to assign hydraulic fracturing microseismic data to the channel sand body heterogeneous attribute model to establish the target gas reservoir basic model; A simulation determination module is used to assign initial gas-water property parameters, fracturing crack parameters and bottom hole flow pressure change curve to the target gas reservoir basic model to establish a target gas reservoir numerical simulation model; A dynamic determination module is used to obtain the production dynamics of the target gas reservoir numerical simulation model, wherein the production dynamics include the curves of daily water production and daily gas production changing with time; The third determination module is used to adjust the gas-water attribute parameters and the fracturing crack parameters until the production performance of the obtained target gas reservoir numerical simulation model is consistent with the actual production performance, and determine the actual gas reservoir numerical simulation model of the heterogeneous channel sand body.

15. The system for optimizing fracture parameters of horizontal wells in tight gas reservoir fracturing according to claim 14, characterized in that: The fourth determination unit is used to establish an optimization objective function of the hydraulic fracture parameters according to the cumulative gas production of the hydraulic fracture parameters, and determine a mathematical model for optimizing the fracture parameters of the heterogeneous river channel sand body.

16. The system for optimizing fracture parameters of horizontal wells in tight gas reservoir fracturing according to claim 15, characterized in that: The optimization objective function of the fracturing crack parameters is expressed as: Among them, u * represents the optimal crack parameter after optimization, u m represents the hydraulic fracture parameters, U represents the feasible domain of the hydraulic fracture parameters, J(u m ) represents the fracture parameter u m The cumulative gas production, N t represents the total number of time steps, n represents the nth time step, Δt n Indicates the step size of the nth time step, N stage represents the total number of fracturing stages in the horizontal well, j represents the jth fracture, It represents the average daily gas production of the j-th fracture at the n-th time step.

17. The system for optimizing fracture parameters of horizontal wells in tight gas reservoir fracturing according to claim 16, characterized in that: The parameter optimization unit includes an extraction module, a gas volume determination module, a function determination module and an output module; An extraction module, used for extracting a first solution in a feasible domain of fracturing fracture parameters by using an optimization algorithm; A gas volume determination module, used for assigning the first scheme to the actual gas reservoir numerical simulation model of the heterogeneous river channel sand body to obtain the daily gas production corresponding to the first scheme; A function determination module, configured to determine an objective function of the first scheme according to a daily gas production corresponding to the first scheme; The output module is used to input the first scheme and the objective function corresponding to the first scheme into the optimization algorithm for looping until the optimization process reaches the convergence condition, and output the second scheme that meets the convergence condition and the objective function corresponding to the second scheme.

18. The system for optimizing fracture parameters of horizontal wells in tight gas reservoir fracturing according to claim 17, characterized in that: The convergence conditions include: When the number of iterations reaches a first preset value, and / or the number of times the actual gas reservoir numerical simulation model of the heterogeneous channel sand body is called reaches a second preset value, and / or when the second scheme is updated, the difference between the second scheme and the first scheme is less than a third preset value.

19. A device for optimizing fracture parameters of a horizontal well in a tight gas reservoir, the device comprising at least one processor and at least one memory, the memory being electrically connected to the processor, wherein: The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 8.

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