Method and system for predicting parameters of fracture derived from strike-slip fracture

Abstract

The invention provides a strike-slip fracture derived fracture parameter prediction method and system, and belongs to the field of oil and gas field exploration and development. The method comprises the following steps: based on three-dimensional seismic data interpretation data, establishing a three-dimensional geologic model; carrying out mechanical parameter assignment and gridding processing on the three-dimensional geologic model in sequence based on predetermined rock mechanical parameters to obtain a three-dimensional grid model; based on the three-dimensional grid model and predetermined geological model boundary conditions, solving stress data corresponding to each grid in the three-dimensional grid model to obtain stress distribution data corresponding to a strike-slip fracture formation period; and based on the exploration data and the stress distribution data corresponding to the strike-slip fracture formation period, predicting the occurrence and development degree of the strike-slip fracture derived tectonic fracture to obtain a strike-slip fracture derived fracture parameter prediction result. The purpose of quantitatively predicting the occurrence and development degree of the derived fracture in the strike-slip fracture forming process is achieved, and the problem of parameter prediction of the derived fracture in the strike-slip fracture forming process is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil and gas field exploration and development, in particular to a strike-slip fault derived fracture parameter prediction method, a strike-slip fault derived fracture parameter prediction system, a machine readable storage medium and an electronic device. BACKGROUND

[0002] In the exploration and development process of fractured oil and gas reservoirs, natural fractures are both reservoir spaces and seepage channels for oil and gas. The development characteristics of natural fractures are crucial for well site optimization and productivity evaluation. There are five main types of existing fracture prediction methods, namely, rock curvature method, fracture fractal method, seismic method, stress field numerical simulation method, and comprehensive method. These five methods have been applied to a certain extent in natural fracture prediction. The rock curvature method is suitable for predicting natural fractures formed by stratum folding deformation; the fracture fractal method is mainly suitable for predicting fractures and fracture systems with obvious self-similarity characteristics; the seismic data method is limited by the resolution of seismic data and can only be used to predict relatively large-scale fractures; the stress field simulation-based method is widely used in fracture prediction, but it is mainly applied in rift basins or areas with simple fault tectonic activity; the comprehensive method is a compromise method taken due to the limitations of single methods in fracture prediction. In summary, the applicability and accuracy of the five types of fracture prediction methods are limited, and they cannot effectively predict the development characteristics of derived fractures in the formation process of strike-slip faults.

[0003] Therefore, how to quantitatively predict the occurrence and development degree of natural fractures derived in the formation process of strike-slip faults to effectively predict the parameters of derived fractures in the formation process of strike-slip faults is a problem that needs to be solved. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a strike-slip fault derived fracture parameter prediction method and system to at least solve the problem of how to quantitatively predict the occurrence and development degree of natural fractures derived in the formation process of strike-slip faults.

[0005] To achieve the above-mentioned purpose, the first aspect of the present application provides a strike-slip fault derived fracture parameter prediction method, comprising:

[0006] establishing a three-dimensional geological model based on three-dimensional seismic data interpretation data;

[0007] based on pre-determined rock mechanics parameters, sequentially performing mechanical parameter assignment and gridding processing on the three-dimensional geological model to obtain a three-dimensional grid model;

[0008] based on the three-dimensional grid model and pre-determined geological model boundary conditions, solving the stress data corresponding to each grid in the three-dimensional grid model to obtain stress distribution data corresponding to the formation period of the strike-slip fault;

[0009] Based on the exploration data and the stress distribution data corresponding to the formation period of the strike-slip fault, the occurrence and development degree of the derived structural fractures of the strike-slip fault are predicted, and a derived fracture parameter prediction result of the strike-slip fault is obtained.

[0010] Optionally, the three-dimensional seismic data interpretation data include fault data and horizon data interpreted from the three-dimensional seismic data, and the three-dimensional seismic data include drilling data, logging data, acoustic curve data, density curve data and drilling mud loss data.

[0011] The acquisition rule of the three-dimensional seismic data interpretation data includes:

[0012] Based on the preset modeling requirement data and the geographic data of the target region, three-dimensional seismic data interpretation density data are determined.

[0013] Based on the three-dimensional seismic data interpretation density data, the drilling data, the logging data, the acoustic curve data and the density curve data, well-seismic calibration is performed to obtain horizon data interpreted from the three-dimensional seismic data.

[0014] Based on the three-dimensional seismic data interpretation density data, the drilling mud loss data and a plurality of seismic attributes, breakpoint determination is performed to obtain fault data interpreted from the three-dimensional seismic data.

[0015] Optionally, the determination rule of the rock mechanics parameters includes:

[0016] Dynamic rock mechanics parameters are calculated by using dipole sonic logging data.

[0017] Static rock mechanics parameters are obtained through triaxial rock mechanics experiments.

[0018] A conversion relationship between the dynamic rock mechanics parameters and the static rock mechanics parameters is established, and rock mechanics parameters conforming to the three-dimensional geological model are determined.

[0019] Optionally, the three-dimensional geological model is sequentially subjected to mechanical parameter assignment and gridding processing based on the rock mechanics parameters determined in advance, including:

[0020] The three-dimensional geological model is subjected to mechanical parameter assignment by using the rock mechanics parameters determined in advance.

[0021] The three-dimensional geological model subjected to the mechanical parameter assignment is subjected to triangular element gridding processing.

[0022] Optionally, the boundary condition of the geological model includes a stress boundary condition, and the stress boundary condition is used to represent the stress size and stress direction applied to the three-dimensional grid model.

[0023] Optionally, the exploration data include core data and electrical imaging logging data.

[0024] Based on exploration data and stress distribution data corresponding to the formation period of strike-slip faults, the development degree of fractures in strike-slip fault-derived structures is predicted, including:

[0025] Based on core data and electrical imaging logging data, the types of fractures derived from strike-slip faults and the proportion of each fracture type in the total structural fractures were determined.

[0026] The degree of fracture development for each fracture type was characterized by the fracture development coefficient corresponding to each fracture type; the fracture development coefficient was determined based on core data and electrical imaging logging data.

[0027] Based on the proportion of each type of fracture in the total structural fractures and the fracture development coefficient corresponding to each fracture type, the value of the comprehensive fracture development coefficient is obtained. The comprehensive fracture development coefficient is used to characterize the degree of development of fractures derived from strike-slip faults, and the value of the comprehensive fracture development coefficient is proportional to the probability of rock fracture formation.

[0028] Optionally, the crack types of the strike-slip fracture-derived structural cracks mentioned above include shear cracks and tensile cracks.

[0029] The above-mentioned characterization of the degree of fracture development for each fracture type using the fracture development coefficient corresponding to each fracture type includes:

[0030] The shear fracture development coefficient is used to characterize the degree of shear fracture development; among which,

[0031] The shear fracture development coefficient is expressed as:

[0032]

[0033] Where S represents the shear fracture development coefficient, σ1 represents the maximum principal stress, σ3 represents the minimum principal stress, and φ represents the internal friction angle of the rock;

[0034] The degree of tensile fracture development is characterized by the tensile fracture development coefficient; among which,

[0035] The tensile rupture development coefficient is expressed as:

[0036] T = σ T / σ T ′;

[0037] Where T is the tensile fracture development coefficient, σ T σ' represents the tensile strength of the rock, when the rock is subjected to stress σ. T Exceeding the tensile strength σ of the rock T At that time, the rock underwent tensile fracturing.

[0038] Optionally, the expression for the above-mentioned comprehensive rupture development coefficient is as follows:

[0039]

[0040] In the formula, I F is a comprehensive fracture development coefficient, a represents the proportion of shear fractures in total tectonic fractures in the rock, b represents the proportion of tensile fractures in total tectonic fractures in the rock, S is a shear fracture development coefficient, and T is a tensile fracture development coefficient.

[0041] Optionally, the fracture types of the strike-slip fault derived tectonic fractures include shear fractures and tensile fractures.

[0042] Based on exploration data and stress distribution data corresponding to the strike-slip fault formation period, the occurrence of the strike-slip fault derived tectonic fractures is predicted, including:

[0043] Based on exploration data and stress distribution data corresponding to the strike-slip fault formation period, the occurrence of the shear fractures is predicted by using the Coulomb-Mohr criterion, and the occurrence of the tensile fractures is predicted by using the Griffith criterion.

[0044] The second aspect of the present application provides a strike-slip fault derived fracture parameter prediction system, including:

[0045] The three-dimensional geological model establishing module is configured to establish a three-dimensional geological model based on three-dimensional seismic data interpretation data.

[0046] The gridding processing module is configured to perform mechanical parameter assignment and gridding processing on the three-dimensional geological model in sequence based on pre-determined rock mechanics parameters, to obtain a three-dimensional grid model.

[0047] The stress data solving module is configured to solve stress data corresponding to each grid in the three-dimensional grid model based on the three-dimensional grid model and pre-determined geological model boundary conditions, to obtain stress distribution data corresponding to the strike-slip fault formation period.

[0048] The derived fracture prediction module is configured to predict the occurrence and development degree of the strike-slip fault derived tectonic fractures based on exploration data and stress distribution data corresponding to the strike-slip fault formation period, to obtain a strike-slip fault derived fracture parameter prediction result.

[0049] The third aspect of the present application provides a machine-readable storage medium, which stores instructions, and the instructions, when executed by a processor, configure the processor to perform the above-described strike-slip fault derived fracture parameter prediction method.

[0050] The fourth aspect of the present application provides an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor, when executing the computer program, implements the above-described strike-slip fault derived fracture parameter prediction method.

[0051] By the technical scheme, a strike-slip fault derived fracture parameter prediction method and system are provided, three-dimensional seismic data interpretation data are used to establish a three-dimensional geological model, rock mechanics parameters are determined in advance, the three-dimensional geological model is subjected to mechanics parameter assignment, and then the three-dimensional geological model subjected to the mechanics parameter assignment is subjected to grid processing to obtain a three-dimensional grid model. A predetermined geological model boundary condition is applied to the three-dimensional grid model, and stress data corresponding to each grid in the three-dimensional grid model are solved to obtain stress distribution data corresponding to a strike-slip fault formation period. Based on exploration data, the mechanical properties of fractures in a single well are analyzed and evaluated, the occurrence and development degree of a strike-slip fault derived structural fracture are predicted in combination with the stress distribution data corresponding to the strike-slip fault formation period, and a strike-slip fault derived fracture parameter prediction result is obtained. Therefore, the occurrence and development degree of natural fractures derived in a strike-slip fault formation process are quantitatively predicted, and the problem of derived fracture parameter prediction in the strike-slip fault formation process is solved. The development strength and occurrence of the strike-slip fault derived fractures have high application value for exploration and development of a fault-controlled fracture reservoir.

[0052] Other features and advantages of the present application will be described in detail in the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0053] The accompanying drawings are included to provide a further understanding of the present application and are incorporated in and constitute a part of the specification, illustrate embodiments of the present application and serve to explain the principles of the present application, but are not intended to limit the present application. In the drawings:

[0054] Figure 1 is a flowchart of a strike-slip fault derived fracture parameter prediction method provided by an embodiment of the present application;

[0055] Figure 2 is a flowchart of another strike-slip fault derived fracture parameter prediction method provided by an embodiment of the present application;

[0056] Figure 3 is a schematic diagram of a planar strike feature of a region A provided by an embodiment of the present application;

[0057] Figure 4 is a schematic diagram of fracture occurrence interpreted by resistivity imaging logging provided by an embodiment of the present application;

[0058] Figure 5 is a well-to-well comparison diagram of Ordovician carbonate rock fracture density provided by an embodiment of the present application;

[0059] Figure 6 is a schematic diagram of a three-dimensional geological model provided by an embodiment of the present application;

[0060] Figure 7 is a schematic diagram of a single-well rock mechanics profile provided by an embodiment of the present application;

[0061] Figure 8 is a rock mechanics parameter conversion relationship provided by an embodiment of the present application;

[0062] Figure 9 is a schematic diagram of a three-dimensional grid model provided by an embodiment of the present application;

[0063] Figure 10 is a schematic diagram of model loading boundary conditions provided by an embodiment of the present application;

[0064] Figure 11 is a schematic diagram of a stress field distribution in a strike-slip fault formation period in region A provided by an embodiment of the present application;

[0065] Figure 12 is a schematic diagram of a strike-slip fault-derived fracture occurrence distribution in region A provided by an embodiment of the present application;

[0066] Figure 13 is a schematic diagram of another strike-slip fault-derived fracture occurrence distribution in region A provided by an embodiment of the present application;

[0067] Figure 14 is a schematic diagram of still another strike-slip fault-derived fracture occurrence distribution in region A provided by an embodiment of the present application;

[0068] Figure 15 is a schematic diagram of a strike-slip fault-derived fracture development intensity distribution in region A provided by an embodiment of the present application;

[0069] Figure 16 is a block diagram of a strike-slip fault-derived fracture parameter prediction system provided by an embodiment of the present application. DETAILED DESCRIPTION

[0070] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present application, and are not intended to limit the present application.

[0071] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0072] Embodiment 1

[0073] Figure 1 is a flowchart of a strike-slip fault-derived fracture parameter prediction method provided by an embodiment of the present application. As shown in Figure 1As shown, the embodiment of the present application provides a strike-slip fault derived crack parameter prediction method, comprising:

[0074] S110: based on three-dimensional seismic data interpretation data, a three-dimensional geological model is established;

[0075] Specifically, the three-dimensional seismic data interpretation data includes fault data and horizon data of the target area interpreted from the three-dimensional seismic data. Based on the fault data and horizon data of the target area interpreted from the three-dimensional seismic data, the corresponding three-dimensional geological model of the target area is established.

[0076] In some embodiments of the present embodiment, the three-dimensional seismic data includes drilling data, logging data, acoustic curve, density curve and drilling mud loss data of the target area; the acquisition rules of the above-mentioned three-dimensional seismic data interpretation data include:

[0077] Based on the preset modeling requirement data and the geographic data of the target area, the three-dimensional seismic data interpretation density data is determined;

[0078] Specifically, according to the research target and the accuracy requirement (i.e. the preset modeling requirement data), the three-dimensional seismic data interpretation density data corresponding to the target area is determined in combination with the work area data (i.e. the geographic data of the target area).

[0079] Based on the three-dimensional seismic data interpretation density data, drilling data, logging data, acoustic curve and density curve, well-seismic calibration is performed to obtain horizon data interpreted from the three-dimensional seismic data;

[0080] Specifically, based on the three-dimensional seismic data interpretation density data, drilling data, logging data, acoustic curve and density curve within the corresponding range are determined and utilized to perform well-seismic calibration to determine the target geological horizon, so as to achieve the effect of fine tracking of the horizon, and obtain the horizon data of the target area interpreted from the three-dimensional seismic data.

[0081] Based on the three-dimensional seismic data interpretation density data, drilling mud loss data and multiple seismic attributes, the determination of breakpoints is performed to obtain fault data interpreted from the three-dimensional seismic data.

[0082] Specifically, the drilling mud loss data and multiple seismic attributes (such as ant body, variance, etc.) are comprehensively utilized to accurately determine the breakpoints, and according to the determined breakpoints, the faults are finely depicted in space to obtain the fault data of the target area interpreted from the three-dimensional seismic data. Thus, the faults and horizons of the target area interpreted from the high-precision three-dimensional seismic data can be utilized to establish a three-dimensional geological model, thereby ensuring the accuracy of the three-dimensional geological model.

[0083] S120: based on the rock mechanics parameters determined in advance, the three-dimensional geological model is sequentially subjected to mechanical parameter assignment and gridding processing to obtain a three-dimensional grid model;

[0084] In some embodiments of the present embodiment, the above-mentioned sequentially performing mechanical parameter assignment and meshing processing on the three-dimensional geological model based on the predetermined rock mechanical parameters comprises: performing mechanical parameter assignment on the three-dimensional geological model by using the predetermined rock mechanical parameters; and performing triangular element meshing processing on the three-dimensional geological model after the mechanical parameter assignment.

[0085] Specifically, the three-dimensional geological model is subjected to mechanical parameter assignment and triangular element meshing processing to obtain a three-dimensional mesh model. Triangular element meshing can better describe the relatively complex curved surfaces in the three-dimensional geological model.

[0086] S130: based on the three-dimensional mesh model and the predetermined geological model boundary conditions, stress data corresponding to each mesh in the three-dimensional mesh model is solved to obtain stress distribution data corresponding to the strike-slip fault formation period;

[0087] Specifically, the predetermined geological model boundary conditions are applied on the three-dimensional mesh model, and the stress state of any mesh element in the three-dimensional mesh model can be solved by using Hooke's law, and finally the distribution data of the principal stress of the study area (i.e. the target area) in the strike-slip fault formation period is obtained.

[0088] The above-mentioned geological model boundary conditions include stress boundary conditions, which are used to represent the stress size and stress direction applied on the three-dimensional mesh model.

[0089] Specifically, the stress boundary conditions are commonly used in the process of constructing stress field simulation. Determining the stress boundary conditions is to determine the stress size and stress direction applied on the three-dimensional mesh model. The overburden stress size in the fault formation period can be determined by one of the following methods: according to the present tectonic characteristics, the stratum denudation amount is determined to restore the paleo-tectonic characteristics of the overburden stratum in the strike-slip fault formation period; the paleo-biological data of the study area is used to determine whether the overburden stratum in the strike-slip fault formation period is subjected to denudation, such as the continuous development of standard paleo-fossils, which indicates that the stratum is continuously deposited. The core acoustic emission experiment results and iterative boundary element inversion are used to determine the fault formation period; according to the Anderson fault theory, one of the three principal stresses is the vertical direction, and the stress direction in the fault formation period is mainly to determine the horizontal principal stress direction, and the stress including one of the following methods to determine the horizontal principal stress direction: the angle between the en echelon normal fault developed in the overburden stratum of the strike-slip main displacement zone and the main fault is used to inverse the horizontal stress direction in the fault formation period; under the constraint of different mechanical properties of the core and imaging logging interpretation cracks, the iterative boundary element method is used to equivalent inversion of the horizontal stress direction in the strike-slip fault formation period.

[0090] S140: Based on the exploration data and the stress distribution data corresponding to the formation period of the strike-slip fault, the occurrence and development degree of the structural fracture derived from the strike-slip fault are predicted, and a strike-slip fault derived fracture parameter prediction result is obtained.

[0091] The strike-slip fault derived fracture parameter includes the occurrence and development degree of the structural fracture derived from the strike-slip fault.

[0092] Specifically, the above exploration data includes core data and electrical imaging logging data. The mechanical properties and development degree of the structural fracture derived from the strike-slip fault are determined by comprehensively utilizing the core data and the electrical imaging logging data. The electrical resistivity imaging logging can identify the fracture by measuring the change of the electrical resistivity around the well, and the core and the thin section can directly observe the fracture. The mechanical properties of the fracture reflect the stress state when the fracture is formed. According to the mechanical properties of the fracture, the fracture can be generally divided into tension fracture, shear fracture and compression fracture. The tension fracture on the core is usually wide, the fracture surface is irregular, and the dip angle is usually large. The shear fracture is usually small in width, the fracture surface is usually smooth, and scratches and steps can be seen. In the carbonate reservoir, the suture line is a typical compression fracture. For the well section without coring, the properties of the fracture are determined by using the electrical resistivity imaging logging under the scale of the cored well section. The proportions of the shear fracture and the tension fracture in the study area (i.e. the target area) are determined by comprehensively utilizing the core, the thin section and the electrical imaging logging. Under the core calibration, the electrical resistivity imaging logging can not only explain the mechanical properties of the fracture, but also accurately explain the occurrence of the fracture. According to the interpretation result of the imaging logging, the fracture line density of a single well can be calculated by using the formula wherein MD represents the well depth, FD(MD) represents the fracture density value at a certain depth, CL represents the fracture cumulative number curve, and W represents the window length, which is usually greater than 1. Thus, according to the statistical result of the mechanical properties of the fracture explained by the core data and the electrical imaging logging data, it is shown that the structural fracture derived from the strike-slip fault is mainly the shear fracture and the tension fracture.

[0093] In some embodiments of the present embodiment, the fracture type of the structural fracture derived from the strike-slip fault includes the shear fracture and the tension fracture; based on the exploration data and the stress distribution data corresponding to the formation period of the strike-slip fault, the development degree of the structural fracture derived from the strike-slip fault is predicted, including: based on the core data and the electrical imaging logging data, the proportions of each fracture type of the structural fracture derived from the strike-slip fault and each fracture type in the total structural fracture are determined; the fracture development degree of each fracture type is characterized by using the corresponding breakage development coefficient of each fracture type; wherein the breakage development coefficient is determined based on the core data and the electrical imaging logging data; based on the proportions of each fracture type in the total structural fracture and the corresponding breakage development coefficient of each fracture type, the value of the comprehensive breakage development coefficient is obtained; wherein the comprehensive breakage development coefficient is used to characterize the development degree of the structural fracture derived from the strike-slip fault, and the value of the comprehensive breakage development coefficient is proportional to the probability of rock producing a fracture.

[0094] In some embodiments of the present embodiment, the above-mentioned use of the fracture development coefficient corresponding to each fracture type to represent the fracture development degree of each fracture type comprises: using a shear fracture development coefficient to represent the shear fracture development degree; wherein the shear fracture development coefficient is represented as: S = σ wherein S represents the shear fracture development coefficient, σ1 represents the maximum principal stress, σ3 represents the minimum principal stress, and φ represents the internal friction angle of the rock; and using a tensile fracture development coefficient to represent the fracture development degree of the tensile fracture; wherein the tensile fracture development coefficient is represented as: T = σ T / σ T ′; wherein T is the tensile fracture development coefficient, σ T ′ is the tensile strength of the rock, and when the stress σ T experienced by the rock exceeds the tensile strength σ T ′ of the rock, the rock will undergo tensile fracture.

[0095] In some embodiments of the present embodiment, the expression of the above-mentioned comprehensive fracture development coefficient is as follows: In the formula, I F is the comprehensive fracture development coefficient, a represents the proportion of shear fractures in the total tectonic fractures in the rock, b represents the proportion of tensile fractures in the total tectonic fractures in the rock, S is the shear fracture development coefficient, and T is the tensile fracture development coefficient.

[0096] Specifically, in the formation process of strike-slip faults, mainly shear fractures and tensile fractures are derived, the shear fracture development degree is represented by introducing a shear fracture development coefficient, and the development of underground rock tensile fractures is reflected by a tensile fracture development coefficient. For the development degree of tectonic fractures derived from strike-slip faults, a comprehensive fracture development coefficient is introduced to represent the development degree, and the higher the value of the comprehensive fracture development coefficient, the greater the probability of rock fracture and crack.

[0097] In some embodiments of the present embodiment, the fracture types of the tectonic fractures derived from strike-slip faults include shear fractures and tensile fractures; and the occurrence of the tectonic fractures derived from strike-slip faults is predicted based on exploration data and stress distribution data corresponding to the formation period of the strike-slip faults, comprising: predicting the occurrence of shear fractures based on the exploration data and the stress distribution data corresponding to the formation period of the strike-slip faults by using the Coulomb-Mohr criterion, and predicting the occurrence of tensile fractures by using the Griffith criterion.

[0098] Specifically, shear fractures usually exist in a conjugate form, and the occurrence of shear fractures can be represented by using the Coulomb-Mohr criterion, and the strike direction of the shear fractures usually has the following functional relationship with the local maximum principal stress direction at the time of formation: In the formula, α is the included angle between the conjugate shear fracture and the maximum principal stress direction, and φ is the internal friction angle of the rock. The fracture dip angle can be represented as: where η is the fracture dip angle, n x , n y , n z are three components of the fracture normal vector in the earth coordinate system. Griffith criterion can be used to characterize the tensile failure of brittle rocks, which can be expressed as: when σ1+3σ2≥0, the failure criterion is: When σ1+3σ2<0, the failure criterion can be simplified as: σ1=-σ T , sin2β=0; where σ T is the tensile strength of the rock, σ1and σ2are the principal stresses, and β is the rock failure angle.

[0099] In the above implementation process, the method uses core data and electrical imaging logging data to analyze and evaluate the mechanical properties and development degree of the fractures in a single well, establishes a three-dimensional geological model based on fault data and horizon data interpreted from three-dimensional seismic data, and establishes a single-well dynamic and static rock mechanics profile using dipole sonic logging data and rock mechanics experiments, and performs mechanical parameter assignment and gridding on the three-dimensional geological model. Under the constraint of regional tectonic evolution background, reasonable geological model boundary conditions are determined by comprehensively using multiple methods, the stress field distribution in the strike-slip fault formation period is simulated, and on this basis, the development degree of tensile fractures and shear fractures is predicted using a tensile fracture development coefficient and a shear fracture development coefficient, respectively. Combined with the statistical results of cores and imaging logging, a comprehensive fracture development coefficient is introduced to predict the development degree of the strike-slip fault-derived fractures. Meanwhile, the Coulomb-Morh criterion and the Griffith criterion are used to predict the occurrence of the strike-slip fault-derived fractures. Thus, the purpose of quantitatively predicting the occurrence and development degree of the natural fractures derived in the strike-slip fault formation process is achieved, and the problem of predicting the parameters of the derived fractures in the strike-slip fault formation process is solved. The development strength and occurrence of the strike-slip fault-derived fractures have high application value for the exploration and development of fault-controlled fracture reservoirs.

[0100] In some embodiments of the present embodiment, the determination rule of the rock mechanics parameters includes:

[0101] Dynamic rock mechanics parameters are calculated using dipole sonic logging data; wherein the related formula is as follows:

[0102]

[0103]

[0104] where E d is the dynamic Young's modulus of the rock, v d is the dynamic Poisson's ratio, ρ is the rock bulk density, V p is the longitudinal wave velocity, and V s is the transverse wave velocity.

[0105] The static rock mechanics parameters are obtained through triaxial rock mechanics experiments;

[0106] Exemplarily, the experimental data of the static rock mechanics parameters are shown in Table 1:

[0107] Table 1 Static rock mechanics parameter table

[0108]

[0109] The conversion relationship between the dynamic rock mechanics parameters and the static rock mechanics parameters is established, and the rock mechanics parameters conforming to the three-dimensional geological model are determined.

[0110] Embodiment 2

[0111] Please refer to Figure 2 , Figure 2 is a flow chart of another strike-slip fault derived fracture parameter prediction method provided by an embodiment of the present application. The embodiment of the present application provides a strike-slip fault derived fracture parameter prediction method, which can be applied to the prediction of derived fracture parameters of strike-slip faults in an A area. The planar strike characteristics of the A area are as shown in Figure 3 , Figure 3 is a schematic diagram of the planar strike characteristics of the A area. The oil and gas in the A area is mainly distributed in the fault-controlled fractured carbonate reservoir. The development intensity and occurrence of derived fractures when the strike-slip fault is formed play a crucial role in the exploration and development of the oil and gas reservoir. The specific steps are as follows:

[0112] Step 1: Single-well fracture property determination and fracture parameter interpretation;

[0113] Specifically, the mechanical properties and development degree of the strike-slip fault derived fractures are determined by comprehensively utilizing the core and electrical imaging logging data. The resistivity imaging logging can identify the fractures by measuring the change of the resistivity around the well, and the core can directly observe the fractures. The mechanical properties of the fractures reflect the stress state when the fractures are formed. According to the mechanical properties of the fractures, the fractures can be generally divided into tension fractures, shear fractures and compression fractures. The tension fractures on the core are usually wide, the fracture surface is irregular, and the dip angle is usually large. The shear fractures are characterized by small fracture width and usually flat fracture surface, and the scratches and steps can be seen. In the carbonate reservoir, the suture line is a typical compression fracture. For the well sections without coring, the properties of the fractures are determined by using the resistivity imaging logging under the scale of the cored well sections. The proportions of the shear fractures and the tension fractures in the study area are determined by comprehensively utilizing the core, thin section and electrical imaging logging. Under the core calibration, the resistivity imaging logging can not only interpret the mechanical properties of the fractures, but also accurately interpret the occurrence of the fractures, as shown in Figure 4 , Figure 4is a schematic diagram of fracture occurrence of resistivity imaging logging interpretation provided by an embodiment of the present application, wherein figure a and figure c are resistivity imaging logging interpretation of Ordovician carbonate fracture dip histogram, and figure b and figure d are resistivity imaging logging interpretation of Ordovician carbonate fracture strike rose diagram. According to the interpretation result of the imaging logging, the fracture line density of a single well can be calculated by using formula as shown in formula Figure 5 , Figure 5 is a well-to-well comparison diagram of Ordovician carbonate fracture density provided by an embodiment of the present application, wherein MD represents well depth, FD(MD) represents fracture density value at a certain depth, CL represents fracture cumulative number curve; and W represents window length, which is usually greater than 1.

[0114] Second step: establishing a three-dimensional geological model of the working area based on three-dimensional seismic data interpretation results;

[0115] According to the research target and accuracy requirement, in combination with the working area data, the three-dimensional seismic data interpretation density is determined, the well-to-seismic calibration is performed by using drilling and logging data as well as acoustic and density curves to determine the target geological horizon, the horizon is finely tracked, the break point is accurately determined by comprehensively using drilling mud loss data and various seismic attributes (such as ant body, variance, etc.), the fracture is finely depicted in space, and finally the three-dimensional geological model is established by using the fracture and horizon interpreted by high-precision three-dimensional seismic data, as shown in formula Figure 6 , Figure 6 is a schematic diagram of a three-dimensional geological model provided by an embodiment of the present application.

[0116] Third step: determining rock mechanics parameters and establishing a three-dimensional grid model;

[0117] The dynamic rock mechanics parameters are obtained by using dipole acoustic logging data, as shown in formula Figure 7 , Figure 7 is a schematic diagram of a single well rock mechanics profile provided by an embodiment of the present application, and the related calculation formula is as follows:

[0118]

[0119]

[0120] In the formula, E d is dynamic Young's modulus of rock, v d is dynamic Poisson's ratio, p is rock bulk density, Vp and Vs are respectively longitudinal wave velocity and transverse wave velocity;

[0121] The static rock mechanics parameters are obtained through triaxial rock mechanics experiments, and the specific data are shown in Table 2.

[0122] Table 2 rock mechanics parameters of Ordovician in A area fracture zone

[0123]

[0124] Please refer to Figure 8 , Figure 8 is the rock mechanics parameter conversion relationship provided by an embodiment of the application. A conversion relationship between dynamic rock mechanics parameters and static rock mechanics parameters is established, rock mechanics parameters of a three-dimensional geological model are determined, the three-dimensional geological model is assigned with the rock mechanics parameters to obtain a three-dimensional rock mechanics model, and the three-dimensional rock mechanics model is triangulated to obtain a three-dimensional grid model. As shown in Figure 9 , Figure 9 is a schematic diagram of the three-dimensional grid model, the established three-dimensional grid model contains 374894 operation nodes and 734930 triangular units.

[0125] Step 4: Determine the boundary conditions of the geological model of the study area.

[0126] There are two kinds of boundary conditions, one is displacement boundary condition, and the other is stress boundary condition. The stress boundary condition is commonly used in the process of constructing a stress field. Determining the stress boundary condition is to determine the stress size and stress direction applied to the geological model. The overburden stress size during the formation of the fault can be determined by one of the following methods: according to the present tectonic characteristics, determine the stratum denudation amount, restore the paleo-tectonic characteristics of the overlying strata during the formation of the strike-slip fault; use the paleontological data of the study area to determine whether the overlying strata of the strike-slip fault are denuded, such as the continuous development of standard paleontological fossils, which indicates that the strata are continuously deposited. The core acoustic emission experiment results and iterative boundary element inversion are comprehensively used to determine; according to the Anderson fault theory, one of the three principal stresses is the vertical direction, and the stress direction during the formation of the fault is mainly to determine the horizontal principal stress direction, which should include one of the following methods: use the angle between the en echelon normal fault developed in the overlying strata of the strike-slip main displacement zone and the main fault to invert the horizontal stress direction during the formation of the fault; under the constraint of different mechanical properties of the core and imaging logging interpretation cracks, the horizontal stress direction during the formation of the strike-slip fault is inversed by using the iterative boundary element method, and finally the 17.5MPa stress generated by the gravity of the overlying strata is applied in the vertical direction, and the maximum horizontal principal stress of 62.4MPa is applied to the right upper and left lower boundaries, and the minimum horizontal principal stress of 3.3MPa is applied to the right lower and left upper boundaries. The loading scheme of the model loading boundary conditions is shown in Figure 10 .

[0127] Step 5: Stress field distribution during the formation of the strike-slip fault.

[0128] The stress boundary conditions determined in the fourth step are applied to the mechanical model after triangulation, and the stress state of any grid cell in the model can be solved by using Hooke's law, and finally the distribution of the three principal stresses of the strike-slip fault formation period in the study area is obtained, as shown in Figure 11 Figure 11 is a schematic diagram of the stress field distribution of the strike-slip fault formation period in region A provided by an embodiment of the present application, wherein a represents the maximum principal stress, b represents the intermediate principal stress, and c represents the minimum principal stress.

[0129] Step 6: Prediction of the occurrence and development degree of the derivative cracks of the strike-slip fault

[0130] The parameters of the derivative cracks of the strike-slip fault mainly refer to the occurrence and development degree of the cracks. The statistical results of the core and imaging interpretation in the first step show that the derivative tectonic cracks in the formation of the strike-slip fault are mainly shear cracks and tensile cracks. The shear cracks usually exist in the form of conjugate, and the strike direction usually has the following functional relationship with the direction of the local maximum principal stress at the time of formation: In the formula, α is the included angle between the conjugate shear cracks and the maximum principal stress direction, and φ is the internal friction angle of the rock. The occurrence of the derivative conjugate shear cracks is shown in Figure 12 and Figure 13 , wherein Figure 12 (a) is the dip angle of the shear crack (I), Figure 12 (b) is the strike of the shear crack (I), Figure 13 (a) is the dip angle of the shear crack (II), Figure 13 (b) is the strike of the shear crack (II). The crack dip angle can be expressed as: In the formula, η is the crack dip angle, and n x , n y , and n z are respectively three components of the crack normal vector in the geodetic coordinate system. The predicted derivative crack dip angle is shown in Figure 12 (a), Figure 13 (a), and Figure 14 (a), Figure 14 is another schematic diagram of the occurrence distribution of the derivative cracks of the strike-slip fault in region A provided by an embodiment of the present application, Figure 14 (a) is the tensile crack dip angle, Figure 14 (b) is the tensile crack strike. Griffith criterion can be used to characterize the tensile rupture of brittle rocks, which can be expressed as:

[0131] When σ1+3σ2≥0, the rupture criterion is:

[0132]

[0133] When σ1+3σ2<0, the rupture criterion can be simplified as: ​

[0134] σ1=-σ T sin2β=0;

[0135] In the formula, σ T σ1 and σ2 are the tensile strength of the rock, σ1 and σ2 are the principal stresses, and β is the rock fracture angle.

[0136] Among them, strike-slip fractures mainly derive from shear fractures and tensile fractures during their formation. The degree of shear fracture development is characterized by a shear fracture development coefficient, which can be expressed by the following formula:

[0137]

[0138] In the formula, S represents the shear fracture development coefficient, σ1 and σ3 are the maximum principal stress and minimum principal stress, respectively, and φ is the internal friction angle of the rock.

[0139] The tensile fracture development coefficient T is used to reflect the development of tensile fractures in underground rocks, and can be expressed by the following formula:

[0140] T = σ T / σ T ′;

[0141] In the formula, σ T σ' represents the tensile strength of the rock. Typically, the tensile strength of rock is about 1 / 10 of its compressive strength. When the rock is subjected to stress σ... T Exceeding the tensile strength σ of the rock T When T ≥ 1, the rock undergoes tensile fracturing.

[0142] The degree of fracture development in strike-slip fault-derived structures is characterized by a comprehensive fracture development coefficient, which can be expressed by the following formula:

[0143]

[0144] In the formula, I F The comprehensive fracture development coefficient is defined as follows: a and b represent the proportions of shear fractures and tensile fractures in the rock structure, respectively. These values ​​can be obtained statistically from core samples and imaging logging. S and T are the shear fracture development coefficient and tensile fracture development coefficient, respectively. When the comprehensive fracture development coefficient I... F The higher the elevation, the greater the probability of the rock fracturing and developing cracks. Please refer to... Figure 15 , Figure 15 This is a schematic diagram of the intensity distribution of strike-slip fault-derived fractures in region A, provided by one embodiment of the present invention. Figure 15 (a) is the shear fracture development coefficient. Figure 15 (b) is the tensile fracture development coefficient. Figure 15 (c) represents the comprehensive fracture development coefficient.

[0145] Embodiment 3

[0146] Figure 16 is a block diagram of a strike-slip fault derived fracture parameter prediction system provided by an embodiment of the present application. As shown in the figure, Figure 16 the embodiment of the present application provides a strike-slip fault derived fracture parameter prediction system, which comprises:

[0147] a three-dimensional geological model establishing module, configured to establish a three-dimensional geological model based on three-dimensional seismic data interpretation data;

[0148] a gridding processing module, configured to perform mechanical parameter assignment and gridding processing on the three-dimensional geological model in sequence based on pre-determined rock mechanics parameters, to obtain a three-dimensional grid model;

[0149] a stress data solving module, configured to solve stress data corresponding to each grid in the three-dimensional grid model based on the three-dimensional grid model and pre-determined geological model boundary conditions, to obtain stress distribution data corresponding to a strike-slip fault formation period;

[0150] a derived fracture prediction module, configured to predict the occurrence and development degree of a strike-slip fault derived structural fracture based on exploration data and the stress distribution data corresponding to the strike-slip fault formation period, to obtain a strike-slip fault derived fracture parameter prediction result.

[0151] Specifically, the system uses three-dimensional seismic data interpretation data to establish a three-dimensional geological model. After performing mechanical parameter assignment on the three-dimensional geological model using pre-determined rock mechanics parameters, the three-dimensional geological model after mechanical parameter assignment is subjected to gridding processing, to obtain a three-dimensional grid model. The pre-determined geological model boundary conditions are applied to the three-dimensional grid model, and stress data corresponding to each grid in the three-dimensional grid model are solved, to obtain stress distribution data corresponding to a strike-slip fault formation period. Based on exploration data, the mechanical properties of fractures in a single well are analyzed and evaluated, and the occurrence and development degree of a strike-slip fault derived structural fracture are predicted in combination with the stress distribution data corresponding to the strike-slip fault formation period, to obtain a strike-slip fault derived fracture parameter prediction result. Thus, the purpose of quantitatively predicting the occurrence and development degree of natural fractures derived in a strike-slip fault formation process is achieved, and the problem of derived fracture parameter prediction in a strike-slip fault formation process is solved. The development intensity and occurrence of strike-slip fault derived fractures have high application value for exploration and development of fault-controlled fracture reservoirs.

[0152] The optional embodiments of the embodiments of the present application are described in detail above in combination with the drawings, but the embodiments of the present application are not limited to the specific details in the above-described embodiments. Within the technical concept range of the embodiments of the present application, the technical solutions of the embodiments of the present application can be subjected to various simple modifications, and these simple modifications all belong to the protection range of the embodiments of the present application.

[0153] It should be further noted that the various technical features described in the above embodiments can be combined in any suitable manner, as long as there is no contradiction. In order to avoid unnecessary repetition, various possible combinations are not described again in the embodiments of the present application.

[0154] Those skilled in the art can understand that all or part of the steps of the methods in the above embodiments can be completed by a program instructing related hardware. The program is stored in a storage medium and includes a plurality of instructions for enabling a single-chip microcomputer, a chip or a processor to perform all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk and various storage media that can store program codes.

[0155] In addition, various different embodiments of the embodiments of the present application can also be combined in any suitable manner, as long as they do not deviate from the idea of the embodiments of the present application, and they should also be considered as disclosed in the embodiments of the present application.

Claims

1. A method for predicting parameters of a strike-slip fault-derived fracture, characterized in that, The method comprises the following steps: establishing a three-dimensional geological model based on three-dimensional seismic data interpretation data; assigning mechanical parameters to the three-dimensional geological model based on pre-determined rock mechanics parameters and performing grid processing on the three-dimensional geological model to obtain a three-dimensional grid model; solving stress data corresponding to each grid in the three-dimensional grid model based on the three-dimensional grid model and pre-determined geological model boundary conditions to obtain stress distribution data corresponding to a strike-slip fault formation period; predicting the occurrence and development degree of a strike-slip fault-derived structural fracture based on exploration data and the stress distribution data corresponding to the strike-slip fault formation period to obtain a strike-slip fault-derived fracture parameter prediction result.

2. The strike-slip fault-derived fracture parameter prediction method according to claim 1, characterized in that, The three-dimensional seismic data interpretation data comprises fault data and horizon data interpreted from three-dimensional seismic data, and the three-dimensional seismic data comprises drilling data, logging data, acoustic curves, density curves and drilling mud loss data; The acquisition rules of the three-dimensional seismic data interpretation data comprise: determining three-dimensional seismic data interpretation density data based on pre-set modeling requirement data and geographical data of a target area; performing well-seismic calibration based on three-dimensional seismic data interpretation density data, drilling data, logging data, acoustic curves and density curves to obtain horizon data interpreted from three-dimensional seismic data; determining breakpoints based on three-dimensional seismic data interpretation density data, drilling mud loss data and multiple seismic attributes to obtain fault data interpreted from three-dimensional seismic data.

3. The strike-slip fault-derived fracture parameter prediction method according to claim 1, characterized in that, The determination rules of the rock mechanics parameters comprise: calculating dynamic rock mechanics parameters by using dipole acoustic logging data; obtaining static rock mechanics parameters through triaxial rock mechanics experiments; establishing a conversion relationship between the dynamic rock mechanics parameters and the static rock mechanics parameters to determine rock mechanics parameters conforming to the three-dimensional geological model.

4. The strike-slip fault-derived fracture parameter prediction method according to claim 1, characterized in that, The method of assigning mechanical parameters to the three-dimensional geological model based on pre-determined rock mechanics parameters and performing grid processing on the three-dimensional geological model comprises: assigning mechanical parameters to the three-dimensional geological model by using pre-determined rock mechanics parameters; performing triangular element grid processing on the three-dimensional geological model after the mechanical parameter assignment.

5. The strike-slip fault-derived fracture parameter prediction method of claim 1, wherein, The geological model boundary conditions comprise stress boundary conditions for representing the stress size and stress direction applied to the three-dimensional grid model.

6. The strike-slip fault-derived fracture parameter prediction method of claim 1, wherein, The exploration data comprises core data and electrical imaging logging data; The method of predicting the development degree of a strike-slip fault-derived structural fracture based on exploration data and the stress distribution data corresponding to the strike-slip fault formation period comprises: determining each fracture type of the strike-slip fault-derived structural fracture and the proportion of each fracture type in total structural fractures based on the core data and the electrical imaging logging data; characterizing the fracture development degree of each fracture type by using a corresponding fracture development coefficient of each fracture type; wherein the fracture development coefficient is determined based on the core data and the electrical imaging logging data; obtaining a numerical value of a comprehensive fracture development coefficient based on the proportion of each fracture type in total structural fractures and the corresponding fracture development coefficient of each fracture type; wherein the comprehensive fracture development coefficient is used to represent the development degree of the strike-slip fault-derived structural fracture, and the numerical value of the comprehensive fracture development coefficient is directly proportional to the probability of rock fracture.

7. The strike-slip fault-derived fracture parameter prediction method according to claim 6, characterized in that, The fracture types of the structural fractures derived from the strike-slip faults include shear fractures and tension fractures; The fracture development degree of each fracture type is characterized by using a corresponding fracture development coefficient of each fracture type, including: The shear fracture development degree is characterized by using a shear fracture development coefficient; wherein, The shear fracture development coefficient is expressed as: Wherein, S represents the shear fracture development coefficient, σ1 represents the maximum principal stress, σ3 represents the minimum principal stress, and φ represents the internal friction angle of the rock; The fracture development degree of the tension fracture is characterized by using a tension fracture development coefficient; wherein, The tension fracture development coefficient is expressed as: T = σ T / σ T ′; wherein T is a tensile fracture development coefficient, σ T is the tensile strength of the rock, and when the stress σ T exceeds the tensile strength σ T of the rock, the rock undergoes tensile fracture.

8. The strike-slip fault-derived fracture parameter prediction method according to claim 7, characterized in that, The expression of the comprehensive fracture development coefficient is as follows: wherein I F is the comprehensive fracture development coefficient, a represents the proportion of shear fractures in the total tectonic fractures, b represents the proportion of tension fractures in the total tectonic fractures, S is the shear fracture development coefficient, and T is the tension fracture development coefficient.

9. The strike-slip fault-derived fracture parameter prediction method of claim 1, wherein, The fracture types of the structural fractures derived from the strike-slip faults include shear fractures and tension fractures; The occurrence of the structural fractures derived from the strike-slip faults is predicted based on exploration data and stress distribution data corresponding to the formation period of the strike-slip faults, including: The occurrence of the shear fracture is predicted by using the Coulomb-Mohr criterion based on the exploration data and the stress distribution data corresponding to the formation period of the strike-slip faults, and the occurrence of the tension fracture is predicted by using the Griffith criterion.

10. A system for predicting parameters of strike-slip fracture-derived cracks, characterized in that, Including: A three-dimensional geological model establishing module is configured to establish a three-dimensional geological model based on three-dimensional seismic data interpretation data; A gridding processing module is configured to perform mechanical parameter assignment and gridding processing on the three-dimensional geological model in sequence based on pre-determined rock mechanics parameters, to obtain a three-dimensional grid model; A stress data solving module is configured to solve stress data corresponding to each grid in the three-dimensional grid model based on the three-dimensional grid model and pre-determined geological model boundary conditions, to obtain stress distribution data corresponding to the formation period of the strike-slip faults; A derived fracture predicting module is configured to predict the occurrence and development degree of the structural fractures derived from the strike-slip faults based on exploration data and stress distribution data corresponding to the formation period of the strike-slip faults, to obtain a strike-slip fault derived fracture parameter prediction result.

11. A machine-readable storage medium having instructions stored thereon, the instructions comprising: The instruction, when executed by the processor, causes the processor to be configured to perform the strike-slip fault derived fracture parameter prediction method of any one of claims 1 to 9.

12. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor, when executing the computer program, implements the strike-slip fault derived fracture parameter prediction method of any one of claims 1 to 9.

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