A method, apparatus, electronic device, and medium for evaluating crack activation intensity.

Abstract

This invention discloses a method, apparatus, electronic device, and medium for evaluating fracture activation intensity. The method includes: constructing a three-dimensional structural model based on three-dimensional seismic data of the target area; determining the fracture density curve based on imaging information obtained from imaging logging; constructing a first fracture mesh model, a second fracture mesh model, and a third fracture mesh model by meshing a fused fracture attribute volume, an attribute volume considering the horizontal stress difference ratio, and an attribute volume considering the fracturability index; solving the first, second, and third fracture mesh models respectively using the fracture density curve as a constraint to obtain a fused fracture density model, a geostress fracture density model, and a fracturable fracture density model; and fusing the three fracture density models to obtain a multi-attribute fused fracture activation intensity model. The aim is to accurately identify the ease of activation of artificial fracture networks during hydraulic fracturing.

Description

Technical Field

[0001] This invention relates to the field of unconventional oil and gas extraction technology, and in particular to a method, apparatus, electronic device and medium for evaluating fracture activation intensity. Background Technology

[0002] Hydraulic fracturing is a key technology for unconventional oil and gas development. Essentially, it involves injecting sand and fluid into the reservoir under high pressure to create artificial fractures, allowing oil and gas to be produced along these fractures. Effectively identifying the ease with which these artificial fractures can be activated during hydraulic fracturing is crucial for building unconventional production capacity.

[0003] Currently, there are two main types of methods for predicting fracture activation intensity. One type directly uses geophysical properties to predict the distribution of natural fractures, such as coherence, curvature, ant-like structures, and azimuthal anisotropy, and characterizes the ease of fracture activation by the development intensity of natural fractures. The other type is fracture modeling methods, which integrate three-dimensional seismic properties, tectonic structures, and microseismic monitoring results to construct fracture models, clarify fracture distribution characteristics, and make them easier to activate during hydraulic fracturing.

[0004] While both methods have achieved some success in predicting crack activation intensity, they suffer from significant ambiguity. The former primarily uses the strength of natural cracks to characterize the ease of crack activation, but it fails to consider the primary factor influencing crack activation: changes in the stress field. The latter method improves upon the former by incorporating tectonic and microseismic monitoring data, thus enhancing prediction accuracy, but it still doesn't account for the impact of stress field variations on crack activation. Therefore, current crack activation intensity prediction methods lack reliability and cannot effectively meet practical production needs. Summary of the Invention

[0005] In view of this, the present invention provides a method, apparatus, electronic device, and medium for evaluating fracture activation strength. The aim is to accurately identify the ease of activation of artificial fracture networks during hydraulic fracturing.

[0006] This invention provides a method for evaluating crack activation intensity, the method comprising:

[0007] Based on the three-dimensional seismic data of the target area, a three-dimensional structural model of the target area is constructed;

[0008] Based on the imaging information of the target area obtained from imaging logging, the fracture density curve of the target area is determined;

[0009] A fused crack attribute body is obtained by fusing multiple crack attribute bodies with multiple curvature attributes.

[0010] The first crack mesh model is constructed by meshing the fused crack property volume and building a mesh model based on the three-dimensional construction model.

[0011] Using the crack density curve as a constraint, the first crack mesh model is solved to obtain the fused crack density model;

[0012] By applying the horizontal stress difference ratio of the in-situ stress to the crack property body, the horizontal stress difference ratio property body is obtained;

[0013] A second crack mesh model is constructed by meshing the horizontal stress difference ratio property body and building a second crack mesh model based on the three-dimensional construction model.

[0014] Using the crack density curve as a constraint, the second crack mesh model is solved to obtain the geostress crack density model.

[0015] The fracturability index in the fracturability properties is applied to the fracture property body to obtain the fracturability property body;

[0016] A third fracture mesh model is constructed by meshing the fracture-resistant material and based on the three-dimensional structural model.

[0017] Using the crack density curve as a constraint, the third crack mesh model is solved to obtain a compressible crack density model.

[0018] The fused fracture density model, the geostress fracture density model, and the compressible fracture density model are fused to obtain a multi-attribute fused fracture activation intensity model, which characterizes the fracture activation intensity of the target area.

[0019] Optionally, determining the fracture density curve of the target area based on the imaging information of the target area obtained from imaging logging includes:

[0020] Imaging information of the target layer in a single well within the target area is obtained through imaging logging.

[0021] Calculate the crack density at each point based on the number of cracks at each point in the imaging information;

[0022] The fracture density curve of the single well is constructed by connecting the fracture densities at each point in order of depth.

[0023] Optionally, determining the fracture density curve of the target area based on the imaging information of the target area obtained from imaging logging includes:

[0024] Imaging information of the target layer in multiple wells within the target area is obtained through imaging logging;

[0025] Based on the number of cracks at the same depth point in multiple wells in the imaging information, calculate the crack density at each same depth point;

[0026] By processing the crack density at each point of the same depth, the target crack density at the same depth within the target area is obtained.

[0027] The fracture density curve of a single well is constructed by connecting the target fracture densities at various depths within the target area in depth order.

[0028] Optionally, the step of fusing multiple crack attribute volumes with multiple curvature attributes to obtain a fused crack attribute volume includes:

[0029] Multiple beam domain scale factors can be preset;

[0030] Multiple crack attribute volumes corresponding to the multiple beam domain scale factors are calculated using wavenumber domain fractional derivatives.

[0031] Based on the fracture information of multiple wells in the target section within the target area, determine the fusion coefficient corresponding to each of the multiple fracture attribute volumes;

[0032] The fused crack attribute body is determined based on the plurality of crack attribute bodies and their respective fusion coefficients.

[0033] Optionally, determining the horizontal stress difference ratio of the ground stress includes:

[0034] The vertical stress is obtained by integrating the overlying rock density of the target area.

[0035] The transverse and longitudinal stresses are determined based on the vertical stress, Poisson's ratio, and compliance tensor.

[0036] The horizontal stress difference ratio is determined based on the horizontal axis stress and the vertical axis stress.

[0037] Optionally, determining the fracturability index in the fracturability properties includes:

[0038] The brittleness and Young's modulus of the target region are determined by pre-stack seismic inversion, and the tensile strength and fracture toughness of the target region are obtained.

[0039] The fracturability index of the target region is calculated based on its brittleness, Young's modulus, tensile strength, and fracture toughness.

[0040] Optionally, fusing the fused fracture density model, the geostress fracture density model, and the compressible fracture density model to obtain a multi-attribute fused fracture activation intensity model to characterize the fracture activation intensity of the target region includes:

[0041] The target fusion crack density model is determined based on the fusion crack density model and the corresponding fusion coefficient.

[0042] The target stress fracture density model is determined based on the aforementioned stress fracture density model and the corresponding fusion coefficient.

[0043] The target compressible fracture density model is determined based on the compressible fracture density model and the corresponding fusion coefficient.

[0044] By fusing the target fused fracture density model, the target geostress fracture density model, and the target compressible fracture density model, a multi-attribute fused fracture activation intensity model is obtained to characterize the fracture activation intensity of the target region.

[0045] Compared with prior art, the present invention has the following advantages:

[0046] The present invention provides a method for evaluating fracture activation intensity by introducing a fused fracture density model, a geostress fracture density model considering geostress, and a fracturable fracture density model considering fracturable properties. The method uses multi-attribute fusion technology to fuse these three models together, and uses the fused model to assess the ease of activation of artificial fracture networks during hydraulic fracturing. This improves the accuracy of identifying the ease of activation of artificial fracture networks during hydraulic fracturing, and facilitates guidance for subsequent horizontal well deployment and fracturing optimization.

[0047] A second aspect of the present invention provides an apparatus for evaluating the activation strength of fractures. It aims to accurately identify the ease with which artificial fracture networks can be activated during hydraulic fracturing.

[0048] The present invention provides an apparatus for evaluating the activation intensity of cracks. The apparatus includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it performs the following steps:

[0049] Based on the three-dimensional seismic data of the target area, a three-dimensional structural model of the target area is constructed;

[0050] Based on the imaging information of the target area obtained from imaging logging, the fracture density curve of the target area is determined;

[0051] A fused crack attribute body is obtained by fusing multiple crack attribute bodies with multiple curvature attributes.

[0052] The first crack mesh model is constructed by meshing the fused crack property volume and building a mesh model based on the three-dimensional construction model.

[0053] Using the crack density curve as a constraint, the first crack mesh model is solved to obtain the fused crack density model;

[0054] By applying the horizontal stress difference ratio of the in-situ stress to the crack property body, the horizontal stress difference ratio property body is obtained;

[0055] A second crack mesh model is constructed by meshing the horizontal stress difference ratio property body and building a second crack mesh model based on the three-dimensional construction model.

[0056] Using the crack density curve as a constraint, the second crack mesh model is solved to obtain the geostress crack density model.

[0057] The fracturability index in the fracturability properties is applied to the fracture property body to obtain the fracturability property body;

[0058] A third fracture mesh model is constructed by meshing the fracture-resistant material and based on the three-dimensional structural model.

[0059] Using the crack density curve as a constraint, the third crack mesh model is solved to obtain a compressible crack density model.

[0060] The fused fracture density model, the geostress fracture density model, and the compressible fracture density model are fused to obtain a multi-attribute fused fracture activation intensity model, which characterizes the fracture activation intensity of the target area.

[0061] A third aspect of the present invention provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0062] Memory, used to store computer programs;

[0063] When a processor executes a program stored in memory, it implements the steps in the method for evaluating crack activation intensity as described in the first aspect.

[0064] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of a method for evaluating crack activation intensity as described in the first aspect above. Attached Figure Description

[0065] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0066] Figure 1 This is a flowchart of a method for evaluating crack activation intensity provided by an embodiment of the present invention;

[0067] Figure 2 This is a schematic diagram illustrating the well interpolation method for evaluating fracture activation intensity in an embodiment of the present invention.

[0068] Figure 3 This is a schematic diagram illustrating the analysis of three-dimensional seismic evaluation of crack activation intensity in a method for evaluating crack activation intensity provided in an embodiment of the present invention;

[0069] Figure 4 This is a schematic diagram illustrating the analysis of evaluating fracture activation intensity using a combination of well interpolation, structural constraints, and three-dimensional seismic attributes in an embodiment of the present invention.

[0070] Figure 5 This is a schematic diagram illustrating the analysis of evaluating crack activation intensity using a compressible crack density model in a method for evaluating crack activation intensity provided in an embodiment of the present invention.

[0071] Figure 6 This is a schematic diagram illustrating the analysis of evaluating crack activation intensity using a geostress-crack density model in a method for evaluating crack activation intensity provided in an embodiment of the present invention.

[0072] Figure 7 This is a schematic diagram illustrating the analysis of evaluating crack activation intensity using a fused crack density model in a method for evaluating crack activation intensity provided in an embodiment of the present invention.

[0073] Figure 8 This is a schematic diagram of a device for evaluating crack activation intensity provided in an embodiment of the present invention. Detailed Implementation

[0074] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0075] Figure 1 This is a flowchart of a method for evaluating crack activation intensity provided by an embodiment of the present invention, such as... Figure 1 As shown, the method includes:

[0076] Step S101: Construct a three-dimensional structural model of the target area based on the three-dimensional seismic data of the target area;

[0077] Step S102: Determine the fracture density curve of the target area based on the imaging information of the target area obtained from imaging logging;

[0078] Step S103: By fusing multiple crack attribute volumes with multiple curvature attributes, a fused crack attribute volume is obtained; by meshing the fused crack attribute volume, a first crack mesh model is constructed based on the three-dimensional construction model; using the crack density curve as a constraint, the first crack mesh model is solved to obtain a fused crack density model.

[0079] Step S104: By applying the horizontal stress difference ratio of the ground stress to the fracture attribute body, a horizontal stress difference ratio attribute body is obtained; by meshing the horizontal stress difference ratio attribute body, a second fracture mesh model is constructed based on the three-dimensional structural model; the fracture density curve is used as a constraint to solve the second fracture mesh model to obtain the ground stress fracture density model.

[0080] Step S105: By applying the fracturability index in the fracturability attribute to the fracture attribute body, a fracturable attribute body is obtained; by meshing the fracturable attribute body, a third fracture mesh model is constructed based on the three-dimensional construction model; the fracture density curve is used as a constraint to solve the third fracture mesh model to obtain a fracturable fracture density model.

[0081] Step S106: The fused fracture density model, the geostress fracture density model, and the compressible fracture density model are fused to obtain a multi-attribute fused fracture activation intensity model to characterize the fracture activation intensity of the target area.

[0082] In an embodiment of the present invention, three-dimensional seismic data of the target area for which fracture activation intensity evaluation needs to be performed are obtained. By synthesizing, recording and calibrating the three-dimensional seismic data, the target layer of the target area is determined, and the structural interpretation of the target layer, such as faults and horizons, is performed. Based on the geological characteristics of the target area, fault combination and horizon tracking are performed to establish a three-dimensional structural model of the target area.

[0083] Simultaneously, imaging logging is used to probe the target formation of the exploration well in the target area, and the fracture density curve of the target area is determined based on the detected imaging information. Imaging logging includes electrical imaging logging and acoustic imaging logging.

[0084] After obtaining the three-dimensional structural model and fracture density curve of the target area, various fracture density models are solved. These models include the fused fracture density model, the geostress fracture density model, and the compressible fracture density model.

[0085] Specifically, a fused crack attribute volume is obtained by fusing multiple crack attribute volumes with different curvature properties; then, the fused crack attribute volume is meshed, and a corresponding first crack mesh model is constructed based on the three-dimensional construction model of the target region constructed in step S101; after obtaining the first crack mesh model, the crack density curve of the target region determined in step S102 is used as a constraint, and the first crack mesh model is solved by the Kriging interpolation method to obtain the corresponding fused crack density model.

[0086] By applying the horizontal stress difference ratio of geostress to the fracture attribute volume, a horizontal stress difference ratio attribute volume is obtained, wherein the horizontal stress difference ratio of geostress applied to the fracture attribute volume is a fracture attribute volume with a beam domain scale factor of 1; then, meshing is performed on this horizontal stress difference ratio attribute volume, and a corresponding second fracture mesh model is constructed based on the three-dimensional structural model of the target region constructed in step S101; after obtaining the second fracture mesh model, the fracture density curve of the target region determined in step S102 is used as a constraint, and the second fracture mesh model is solved by the Kriging interpolation method to obtain the corresponding geostress fracture density model.

[0087] By applying the compressibility index from the compressibility attribute to the fracture attribute volume, a compressibility attribute volume is obtained, wherein the compressibility index applied to the fracture attribute volume is a fracture attribute volume with a beam domain scale factor of 1. Then, a mesh is generated on the compressibility attribute volume, and a corresponding third fracture mesh model is constructed based on the three-dimensional structural model of the target region constructed in step S101. After obtaining the third fracture mesh model, the fracture density curve of the target region determined in step S102 is used as a constraint, and the third fracture mesh model is solved by the Kriging interpolation method to obtain the corresponding compressibility fracture density model.

[0088] After obtaining the above three fused fracture density models, geostress fracture density model and fracturing fracture density model, the three fracture density models are fused to obtain a multi-attribute fused fracture activation intensity model. This model will accurately and effectively characterize the fracture activation intensity of the target area, so as to guide the deployment of horizontal wells and fracturing optimization.

[0089] In this invention, determining the fracture density curve of the target area based on the imaging information of the target area obtained by imaging logging includes: obtaining imaging information of the target segment of a single well within the target area through imaging logging; calculating the fracture density of each point based on the number of cracks at each point in the imaging information; and constructing the fracture density curve of the single well by connecting the fracture densities of each point in depth order.

[0090] In an embodiment of the present invention, the target section of the probe well in the target area is probed by imaging logging. The probed imaging information is analyzed to obtain fracture information at different depth points in the target section of the target area. The fracture information includes the number of fractures, fracture dip angle, fracture azimuth angle, etc. Based on the number of fractures at different depth points in the target section of the target area, the fracture density at different depth points in the target area is calculated using the following formula (1). By connecting the fracture densities at different depth points in depth order, a fracture density curve of a single probe well in the target section of the target area is constructed. In an embodiment of the present invention, the fracture density at each depth point in the probe well is calculated using the following formula (1).

[0091]

[0092] Where md is a depth point in the well; Intensity(md) is the fracture density at depth point md in the well; W is the depth point calculation window; and X(md) is the number of fractures at depth point md in the well.

[0093] In this invention, determining the fracture density curve of the target area based on the imaging information of the target area obtained by imaging logging includes: obtaining imaging information of the target segment of multiple wells in the target area through imaging logging; calculating the fracture density at each depth point based on the number of cracks at the same depth point in the multiple wells in the imaging information; obtaining the target crack density at the same depth in the target area by processing the fracture density at each depth point; and constructing the fracture density curve of the single well by connecting the target fracture densities at each depth in the target area in depth order.

[0094] In an embodiment of the present invention, in order to improve the accuracy of the fracture density curve of the target area, imaging information of the target layer of multiple probe wells in the target area is obtained by imaging logging, and all the detected imaging information is analyzed to obtain fracture information at different depths of the target layer in multiple probe wells in the target area.

[0095] One method for calculating the fracture density at the same depth point based on the number of fractures at the same depth point in multiple wells from the imaging information is as follows: The number of fractures at the same depth point in the target region is obtained by comprehensively processing the number of fractures at the same depth point in all probe wells. For example, the number of fractures at the same depth point in the target region is obtained by averaging the number of fractures at the same depth point in all probe wells. Based on the number of fractures at the same depth point in the target region, the fracture density at the same depth point in the target region is calculated using the formula (1) above. Similarly, the fracture density at each depth point in the target region is obtained using the same implementation method as above, where the fracture density at the same depth point in the target region is calculated using formula (1). Then, the fracture densities at different depth points are connected in depth order to construct the fracture density curve of the target segment in the target region.

[0096] One method for calculating the fracture density at the same depth point based on the number of fractures at the same depth point in multiple wells from the imaging information is as follows: For any well among all the exploration wells, the fracture density at different depth points of that well is calculated using the formula (1) above, based on the number of fractures at different depth points of that well. After obtaining the fracture density of each well at different depth points through this implementation method, the fracture density of all wells at the same depth point is comprehensively processed to obtain the fracture density of the target area at that same depth point. For example, the fracture density of the target area at that same depth point is obtained by averaging the fracture density of all wells at the same depth point. Similarly, by obtaining the fracture density of the target area at different depth points through this implementation method, the fracture density curve of the target segment of the target area is constructed by connecting the fracture densities at different depth points in depth order.

[0097] In this invention, the step of fusing multiple fracture attribute volumes with multiple curvature attributes to obtain a fused fracture attribute volume includes: presetting multiple beam domain scale factors; calculating multiple fracture attribute volumes corresponding to the multiple beam domain scale factors respectively using wavenumber domain fractional derivatives; determining the fusion coefficients corresponding to each of the multiple fracture attribute volumes based on multi-well fracture information in the target segment within the target area; and determining the fused fracture attribute volume based on the multiple fracture attribute volumes and their respective fusion coefficients.

[0098] In an embodiment of the present invention, multiple beam domain scale factors are preset, and multiple crack attribute bodies corresponding to the multiple beam domain scale factors are calculated by wavenumber fractional derivative. Then, the multiple crack attribute bodies are fused using the following formula (2) to obtain a fused crack attribute body.

[0099] In an embodiment of the present invention, a preferred implementation of the preset multiple beam domain scaling factors is to preset three beam domain scaling factors with values ​​of K1 = 0.25, K2 = 0.5, and K3 = 0.75 respectively.

[0100] Fuse=aA+bB+cC (2)

[0101] Where Fuse is the fusion crack attribute body, A is the crack attribute body with K1 = 0.25, B is the crack attribute body with K2 = 0.5, C is the crack attribute body with K3 = 0.75, a is the fusion coefficient of crack attribute body A, b is the fusion coefficient of crack attribute body B, and c is the fusion coefficient of crack attribute body C.

[0102] Based on the fracture information from multiple wells in the target layer within the target area, the fusion coefficients corresponding to the fracture attribute volumes with different beam domain scale factors are determined. Specifically, using the fracture information of the target layer from three exploration wells in the target area, three of the above equations (2) can be constructed. When the actual fracture information in the target area is determined, Fuse, A, B, and C in the equations are all known quantities. By solving these equations, the corresponding fusion coefficients a, b, and c of the fracture attribute volumes with different beam domain scale factors can be obtained.

[0103] Based on multiple crack attribute bodies A, B, C and their respective fusion coefficients a, b, c, the fused crack attribute body Fuse can be determined.

[0104] In this invention, the determination of the horizontal stress difference ratio of the geostress includes: obtaining the vertical stress by integrating the overburden density of the target area; determining the transverse and longitudinal stresses based on the vertical stress, Poisson's ratio, and flexibility tensor; and determining the horizontal stress difference ratio based on the transverse and longitudinal stresses.

[0105] In an embodiment of the present invention, the vertical stress σ is obtained by integrating the overburden density of the target area. z The following formula (3) is used to calculate the transverse stress σ based on the vertical stress, Poisson's ratio, and compliance tensor of the target region. x and longitudinal stress σ y Based on the calculated transverse and longitudinal stresses, the horizontal stress difference ratio DHSR of the ground stress is obtained by using the following formula (4).

[0106]

[0107]

[0108] Where, σ z (z) represents the vertical stress; σx For transverse stress; σ y Longitudinal stress; DHSR is the horizontal stress difference ratio; σ is Poisson's ratio, which can be determined through pre-stack seismic inversion; Z N ρ(h) is the compliance tensor, which can be determined through pre-stack seismic inversion; ρ(h) is the overburden density, which can be determined through pre-stack seismic inversion; ε is the anisotropy parameter, which can be determined through ε or P-wave anisotropy inversion; λ is the Lamé constant, which can be determined through pre-stack seismic inversion; μ is the shear modulus, which can be determined through pre-stack seismic inversion; and E is the Young's elastic modulus, which can be determined through pre-stack seismic inversion.

[0109] In this invention, the determination of the fracturability index in the fracturability properties includes: determining the brittleness and Young's modulus of the target region through pre-stack seismic inversion, and obtaining the tensile strength and fracture toughness of the target region; calculating the fracturability index of the target region based on the brittleness, Young's modulus, tensile strength and fracture toughness of the target region.

[0110] In an embodiment of the present invention, the brittleness and Young's modulus of the target region are determined by pre-stack seismic inversion, and the tensile strength and fracture toughness of the target region are obtained. After obtaining the relevant data, based on the obtained brittleness, Young's modulus, tensile strength and fracture toughness of the target region, the compressibility index of the target region is calculated by the following formula (5).

[0111]

[0112] Where FI is the fracturing index; K IC For fracture toughness; S t σ represents tensile strength; B represents brittleness, which can be determined through pre-stack seismic inversion; σ n Vcl represents the confining pressure during testing; Vcl represents the clay content, which can be determined through pre-stack seismic inversion; E represents Young's elastic modulus, which can be determined through pre-stack seismic inversion.

[0113] In this invention, fusing the fused fracture density model, the geostress fracture density model, and the compressible fracture density model to obtain a multi-attribute fused fracture activation intensity model to characterize the fracture activation intensity of the target area includes: determining a target fused fracture density model based on the fused fracture density model and its corresponding fusion coefficient; determining a target geostress fracture density model based on the geostress fracture density model and its corresponding fusion coefficient; determining a target compressible fracture density model based on the compressible fracture density model and its corresponding fusion coefficient; and obtaining a multi-attribute fused fracture activation intensity model to characterize the fracture activation intensity of the target area by fusing the target fused fracture density model, the target geostress fracture density model, and the target compressible fracture density model.

[0114] In an embodiment of the present invention, by solving the fracture information of multiple wells in the target section within the target area, the fusion coefficients corresponding to the fused fracture density model, the geostress fracture density model, and the fracturing fracture density model are obtained. After obtaining the fusion coefficients corresponding to the fused fracture density model, the geostress fracture density model, and the fracturing fracture density model, the multi-attribute fused fracture activation intensity model is calculated using the following formula (6).

[0115] Fuse1 = xX + yY + zZ (6)

[0116] Wherein, Fuse1 is the multi-attribute fused fracture activation intensity model, X is the fused fracture density model, Y is the geostress fracture density model, Z is the compressible fracture density model, x is the fusion coefficient of the fused fracture density model X, y is the fusion coefficient of the geostress fracture density model Y, and z is the fusion coefficient of the compressible fracture density model Z.

[0117] Specifically, a target fused fracture density model is obtained by multiplying the fused fracture density model by the corresponding fusion coefficient; a target in-situ stress fracture density model is obtained by multiplying the in-situ stress fracture density model by the corresponding fusion coefficient; a target compressible fracture density model is obtained by multiplying the compressible fracture density model by the corresponding fusion coefficient; and a multi-attribute fused fracture activation intensity model is obtained by adding and fusing the target fused fracture density model, the target in-situ stress fracture density model, and the target compressible fracture density model, to characterize the fracture activation intensity of the target region.

[0118] The present invention provides a method for evaluating fracture activation intensity by introducing a fused fracture density model, a geostress fracture density model considering geostress, and a fracturable fracture density model considering fracturable properties. The method uses multi-attribute fusion technology to fuse these three models together, and uses the fused model to assess the ease of activation of artificial fracture networks during hydraulic fracturing. This improves the accuracy of identifying the ease of activation of artificial fracture networks during hydraulic fracturing, and facilitates guidance for subsequent horizontal well deployment and fracturing optimization.

[0119] In embodiments of the present invention, such as Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 As shown. Figure 2 The fracture density is obtained by well interpolation. Figure 3 The results of 3D seismic crack prediction. Figure 2 , Figure 3 It is currently the mainstream method for evaluating crack activation intensity. Figure 2The method relies too heavily on wells, and in well-free areas ( Figure 2 (As shown in the ellipse) The results have poor reliability. Figure 3 The method mainly relies on 3D seismic prediction results, without considering the role of actual drilling, resulting in low characterization accuracy. Figure 4 To comprehensively consider well interpolation, structural constraints, and fracture intensity based on three-dimensional seismic properties, this method compensates for... Figure 2 , Figure 3 The two methods have shortcomings, as they do not consider the influence of factors such as stress. Based on this, the present invention considers the influence of stress and fracturability on the crack activation intensity, further improving method 4. Figure 5 For predicting the density of compressible fractures, Figure 6 For the prediction of in-situ stress fracture density based on stress inversion model, Figure 7 For comprehensive Figure 4 , Figure 5 , Figure 6 The results of this study led to the development of a multi-attribute fusion crack activation intensity prediction model. Figure 7 The prediction results combined the results of the other three methods, and after comparative analysis of actual data, the prediction results showed the best agreement with the actual drilling.

[0120] This invention also provides an apparatus 200 for evaluating crack activation intensity, such as... Figure 8 As shown, the device 200 includes: a processor 201 and a memory 202, and a computer program 203 stored in the memory and executable on the processor. When the processor executes the computer program, it performs the following steps:

[0121] Based on the three-dimensional seismic data of the target area, a three-dimensional structural model of the target area is constructed;

[0122] Based on the imaging information of the target area obtained from imaging logging, the fracture density curve of the target area is determined;

[0123] A fused crack attribute body is obtained by fusing multiple crack attribute bodies with multiple curvature attributes.

[0124] The first crack mesh model is constructed by meshing the fused crack property volume and building a mesh model based on the three-dimensional construction model.

[0125] Using the crack density curve as a constraint, the first crack mesh model is solved to obtain the fused crack density model;

[0126] By applying the horizontal stress difference ratio of the in-situ stress to the crack property body, the horizontal stress difference ratio property body is obtained;

[0127] A second crack mesh model is constructed by meshing the horizontal stress difference ratio property body and building a second crack mesh model based on the three-dimensional construction model.

[0128] Using the crack density curve as a constraint, the second crack mesh model is solved to obtain the geostress crack density model.

[0129] The fracturability index in the fracturability properties is applied to the fracture property body to obtain the fracturability property body;

[0130] A third fracture mesh model is constructed by meshing the fracture-resistant material and based on the three-dimensional structural model.

[0131] Using the crack density curve as a constraint, the third crack mesh model is solved to obtain a compressible crack density model.

[0132] The fused fracture density model, the geostress fracture density model, and the compressible fracture density model are fused to obtain a multi-attribute fused fracture activation intensity model, which characterizes the fracture activation intensity of the target area.

[0133] Optionally, the steps performed by the processor in the device 200 when executing the computer program include: determining the fracture density curve of the target area based on the imaging information of the target area obtained from imaging logging, including:

[0134] Imaging information of the target layer in a single well within the target area is obtained through imaging logging;

[0135] Calculate the crack density at each point based on the number of cracks at each point in the imaging information;

[0136] The fracture density curve of the single well is constructed by connecting the fracture densities at each point in order of depth.

[0137] Optionally, the steps performed by the processor in the device 200 when executing the computer program include: determining the fracture density curve of the target area based on the imaging information of the target area obtained from imaging logging, including:

[0138] Imaging information of the target layer in multiple wells within the target area is obtained through imaging logging;

[0139] Based on the number of cracks at the same depth point in multiple wells in the imaging information, calculate the crack density at each same depth point;

[0140] By processing the crack density at each point of the same depth, the target crack density at the same depth within the target area is obtained.

[0141] The fracture density curve of a single well is constructed by connecting the target fracture densities at various depths within the target area in depth order.

[0142] Optionally, the steps performed by the processor in the device 200 when executing the computer program, including: obtaining a fused crack attribute body by fusing multiple crack attribute bodies with multiple curvature attributes, include:

[0143] Multiple beam domain scale factors can be preset;

[0144] Multiple crack attribute volumes corresponding to the multiple beam domain scale factors are calculated using wavenumber domain fractional derivatives.

[0145] Based on the fracture information of multiple wells in the target section within the target area, determine the fusion coefficient corresponding to each of the multiple fracture attribute volumes;

[0146] The fused crack attribute body is determined based on the plurality of crack attribute bodies and their respective fusion coefficients.

[0147] Optionally, the steps performed by the processor when executing the computer program in the device 200, including determining the horizontal stress difference ratio of the ground stress, include:

[0148] The vertical stress is obtained by integrating the overlying rock density of the target area.

[0149] The transverse and longitudinal stresses are determined based on the vertical stress, Poisson's ratio, and compliance tensor.

[0150] The horizontal stress difference ratio is determined based on the horizontal axis stress and the vertical axis stress.

[0151] Optionally, the steps performed by the processor executing the computer program in the device 200, including the determination of the fracturability index in the fracturability properties, include:

[0152] The brittleness and Young's modulus of the target region are determined by pre-stack seismic inversion, and the tensile strength and fracture toughness of the target region are obtained.

[0153] The fracturability index of the target region is calculated based on its brittleness, Young's modulus, tensile strength, and fracture toughness.

[0154] Optionally, the steps performed by the processor in the device 200 when executing the computer program include: fusing the fused fracture density model, the geostress fracture density model, and the compressible fracture density model to obtain a multi-attribute fused fracture activation intensity model to characterize the fracture activation intensity of the target region, including:

[0155] The target fusion crack density model is determined based on the fusion crack density model and the corresponding fusion coefficient.

[0156] The target stress fracture density model is determined based on the aforementioned stress fracture density model and the corresponding fusion coefficient.

[0157] The target compressible fracture density model is determined based on the compressible fracture density model and the corresponding fusion coefficient.

[0158] By fusing the target fused fracture density model, the target geostress fracture density model, and the target compressible fracture density model, a multi-attribute fused fracture activation intensity model is obtained to characterize the fracture activation intensity of the target region.

[0159] This invention also provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; the memory is used to store computer programs; and the processor, when executing the program stored in the memory, implements the steps in the method for evaluating crack activation intensity.

[0160] This invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps in the method for evaluating crack activation intensity.

[0161] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0162] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0163] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A method for evaluating crack activation intensity, characterized in that, The method includes: Based on the three-dimensional seismic data of the target area, a three-dimensional structural model of the target area is constructed; Based on the imaging information of the target area obtained from imaging logging, the fracture density curve of the target area is determined; A fused crack attribute body is obtained by fusing multiple crack attribute bodies with multiple curvature attributes. The first crack mesh model is constructed by meshing the fused crack property volume and building a mesh model based on the three-dimensional construction model. Using the crack density curve as a constraint, the first crack mesh model is solved to obtain the fused crack density model; By applying the horizontal stress difference ratio of the ground stress to the crack property body, the horizontal stress difference ratio property body is obtained; A second crack mesh model is constructed by meshing the horizontal stress difference ratio property body and building a second crack mesh model based on the three-dimensional construction model. Using the crack density curve as a constraint, the second crack mesh model is solved to obtain the geostress crack density model. The fracturability index in the fracturability properties is applied to the fracture property body to obtain the fracturability property body; A third fracture mesh model is constructed by meshing the fracture-resistant material and based on the three-dimensional structural model. Using the crack density curve as a constraint, the third crack mesh model is solved to obtain a compressible crack density model. The fused fracture density model, the geostress fracture density model, and the compressible fracture density model are fused to obtain a multi-attribute fused fracture activation intensity model, which characterizes the fracture activation intensity of the target area.

2. The method for evaluating crack activation intensity according to claim 1, characterized in that, The step of determining the fracture density curve of the target area based on the imaging information of the target area obtained from imaging logging includes: Imaging information of the target layer in a single well within the target area is obtained through imaging logging; Calculate the crack density at each point based on the number of cracks at each point in the imaging information; The fracture density curve of the single well is constructed by connecting the fracture densities at each point in order of depth.

3. The method for evaluating crack activation intensity according to claim 1, characterized in that, The step of determining the fracture density curve of the target area based on the imaging information of the target area obtained from imaging logging includes: Imaging information of the target layer in multiple wells within the target area is obtained through imaging logging; Based on the number of cracks at the same depth point in multiple wells in the imaging information, calculate the crack density at each same depth point; By processing the crack density at each point of the same depth, the target crack density at the same depth within the target area is obtained. A fracture density curve for a single well is constructed by connecting the target fracture densities at various depths within the target area in depth order.

4. The method for evaluating crack activation intensity according to claim 1, characterized in that, The process of fusing multiple crack attribute volumes with multi-curvature properties to obtain a fused crack attribute volume includes: Multiple beam domain scale factors can be preset; Multiple crack attribute volumes corresponding to the multiple beam domain scale factors are calculated using wavenumber domain fractional derivatives. Based on the fracture information of multiple wells in the target section within the target area, determine the fusion coefficient corresponding to each of the multiple fracture attribute volumes; The fused crack attribute body is determined based on the plurality of crack attribute bodies and their respective fusion coefficients.

5. The method for evaluating crack activation intensity according to claim 1, characterized in that, The determination of the horizontal stress difference ratio of the ground stress includes: The vertical stress is obtained by integrating the overlying rock density of the target area. The transverse and longitudinal stresses are determined based on the vertical stress, Poisson's ratio, and compliance tensor. The horizontal stress difference ratio is determined based on the horizontal axis stress and the vertical axis stress.

6. The method for evaluating crack activation intensity according to claim 1, characterized in that, The determination of the fracturability index in the fracturability properties includes: The brittleness and Young's modulus of the target region are determined by pre-stack seismic inversion, and the tensile strength and fracture toughness of the target region are obtained. The fracturability index of the target region is calculated based on its brittleness, Young's modulus, tensile strength, and fracture toughness.

7. The method for evaluating crack activation intensity according to claim 1, characterized in that, The process of fusing the fused fracture density model, the geostress fracture density model, and the compressible fracture density model to obtain a multi-attribute fused fracture activation intensity model to characterize the fracture activation intensity of the target region includes: Based on the fusion crack density model and the corresponding fusion coefficient, the target fusion crack density model is determined; The target stress fracture density model is determined based on the aforementioned stress fracture density model and the corresponding fusion coefficient. The target compressible fracture density model is determined based on the compressible fracture density model and the corresponding fusion coefficient. By fusing the target fused fracture density model, the target geostress fracture density model, and the target compressible fracture density model, a multi-attribute fused fracture activation intensity model is obtained to characterize the fracture activation intensity of the target region.

8. A device for evaluating the activation intensity of cracks, characterized in that, The apparatus for evaluating crack activation intensity includes a processor and a memory, as well as a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it performs the following steps: Based on the three-dimensional seismic data of the target area, a three-dimensional structural model of the target area is constructed; Based on the imaging information of the target area obtained from imaging logging, the fracture density curve of the target area is determined; A fused crack attribute body is obtained by fusing multiple crack attribute bodies with multiple curvature attributes. The first crack mesh model is constructed by meshing the fused crack property volume and building a mesh model based on the three-dimensional construction model. Using the crack density curve as a constraint, the first crack mesh model is solved to obtain the fused crack density model; By applying the horizontal stress difference ratio of the in-situ stress to the crack property body, the horizontal stress difference ratio property body is obtained; A second crack mesh model is constructed by meshing the horizontal stress difference ratio property body and building a second crack mesh model based on the three-dimensional construction model. Using the crack density curve as a constraint, the second crack mesh model is solved to obtain the geostress crack density model. The fracturability index in the fracturability properties is applied to the fracture property body to obtain the fracturability property body; A third fracture mesh model is constructed by meshing the fracture-resistant material and based on the three-dimensional structural model. Using the crack density curve as a constraint, the third crack mesh model is solved to obtain a compressible crack density model. The fused fracture density model, the geostress fracture density model, and the compressible fracture density model are fused to obtain a multi-attribute fused fracture activation intensity model, which characterizes the fracture activation intensity of the target area.

9. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; When executing a program stored in memory, the processor implements the steps of the method for evaluating crack activation intensity as described in any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the steps in the method for evaluating crack activation intensity as described in any one of claims 1-7.

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