Method and system for determining effective fracture distribution under multiple episodes of regional tectonism

Abstract

The present application belongs to the technical field of oil and gas reservoir development evaluation, and discloses a method and system for determining effective fracture distribution under multi-period regional tectonism, which is based on the fracture characteristics and the present horizontal maximum stress direction identified based on imaging logging data, and establishes a mathematical model between the effective fracture distribution and the present horizontal maximum stress direction; the horizontal maximum principal stress direction of the previous period is identified based on the tectonic stress trace distribution map; the influence of the superposition of the horizontal maximum stress direction deflection on the effective fracture distribution is added, and the opening degree of the early invalid fracture to the deflection of the horizontal maximum stress direction is quantified. The present application analyzes the influence of the stress deflection on the effective fracture group, and based on the principle that the effective fracture is the main channel for oil and gas migration, provides support basis for the selection of the sweet spot area, the selection of the well displacement direction and the establishment of better interwell connectivity after obtaining the dominant group of the effective fracture.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas reservoir development evaluation technology, and in particular relates to a method and system for determining the effective fracture distribution under multiple phases of regional tectonic activity. Background Technology

[0002] Currently, formation fractures can be mainly classified into three types according to their genesis: regional tectonic-related fractures, tectonic deformation-related fractures, and fracture-derived fractures. Regional tectonic-related fractures refer to fractures formed by regional stress caused by the collision of tectonic plates before significant deformation occurs in the formation. Regional tectonic-related fractures are a common type of fracture, widely distributed, and their effectiveness is a major factor affecting key parameters such as reservoir permeability and reservoir quality. Therefore, evaluating the effectiveness of regional tectonic-related fractures is an important task in oil and gas reservoir development. Under the influence of regional tectonic stress, two sets of intersecting "X"-shaped conjugate shear fractures with small angles (40–80°) are mainly formed, with the midline of the acute angle intersection pointing to the direction of the maximum horizontal principal stress. In addition, a small number of tensile fractures parallel to the direction of the maximum horizontal principal stress also develop. Regional tectonic-related fractures exhibit a checkerboard distribution in outcrops, widely distributed over large areas, and all develop perpendicular to the formation bedding planes.

[0003] Effective fractures refer to unfilled or partially filled fractures, which serve as important channels for oil and gas accumulation and transport. Studies have found that the effectiveness of fractures related to multiple phases of regional tectonic activity changes with the deflection of the direction of the maximum horizontal principal stress at different stages. In other words, the effectiveness of fractures related to regional tectonic activity develops in coordination with the direction of the maximum horizontal principal stress across multiple phases: as the direction of the maximum horizontal principal stress deflects, the angle between one group of fractures in the early conjugate shear fractures and the maximum horizontal principal stress gradually increases. These fractures are subjected to compression from the maximum horizontal principal stress at a large angle or even perpendicular to it, thus remaining filled or tightly closed, resulting in generally low effectiveness. Conversely, the angle between another group of fractures in the early conjugate shear fractures and the maximum horizontal principal stress gradually decreases. Even if this group of fractures was filled or closed early on, it is easily compressed by the maximum horizontal principal stress at a small angle, causing it to reopen and thus forming effective open fractures. Quantitative evaluation of effective fractures under the deflection of regional tectonic stress is of significant practical importance for assessing the reservoir performance, channeling capacity, and engineering development of oil and gas reservoirs.

[0004] Since the regional fractures develop perpendicular to the ground plane, the four fracture surfaces of a group of two "X"-shaped shear fractures are also perpendicular to the strata. Therefore, it is only necessary to consider the compaction effect of the horizontal regional in-situ stress parallel to the ground plane on the fracture surfaces.

[0005] The control of horizontal geostress over fracture effectiveness is mainly reflected by the angle between the direction of the maximum horizontal geostress and the orientation of the regional fracture (the direction of the regional fracture's extension in a plane parallel to the strata). When the angle is 90 degrees, the fracture surfaces are compressed together to the maximum extent, and the normal stress value of the fracture surface (referring to the force acting perpendicularly on the fracture surface) reaches its maximum at this moment, and the fracture exhibits ineffective characteristics. When the angle is 0 degrees, the normal stress value of the fracture surface is at its minimum at this moment, and the fracture exhibits effective characteristics.

[0006] Existing technologies primarily employ analytical calculations of the normal stress of cracks to reflect the controlling effect of the maximum horizontal ground stress on the effectiveness of regional cracks. That is, the greater the force perpendicular to the crack surface, the worse the crack effectiveness.

[0007] However, the method of analyzing and calculating the crack normal stress to reflect the control effect of the maximum horizontal ground stress on the effectiveness of regional cracks only focuses on the influence of ground stress on crack effectiveness under a certain state, such as the influence of the maximum horizontal ground stress on crack effectiveness when the crack normal stress is at a certain value.

[0008] The shortcoming of this analysis lies in its failure to consider stress variations, i.e., the multi-stage problem, and the impact of multi-stage stress on the effective fracture system. When the direction of geostress deflects, the angle between the direction of the maximum horizontal geostress and the orientation of the regional fractures becomes a variable, varying between 0 and 90 degrees. The corresponding fracture normal stress value will vary between its minimum and maximum values. During the process of geostress direction deflection, in a set of two "X"-shaped shear fractures, only one fracture will have its angle with the direction of the maximum horizontal geostress decrease, thus improving the effectiveness of the fracture with that orientation; the other fracture will remain ineffective. Simultaneously, due to the deflection of the regional geostress direction, the angle between the regional geostress and the orientation of the expansion fracture will also increase during this process, causing the early-filled expansion fractures to remain ineffective.

[0009] In view of this, there is currently no data available for analyzing the impact of multiple phases of geostress on the effective fracture system. Therefore, there is an urgent need to design a method to determine the distribution of effective fractures under multiple phases of regional tectonic activity.

[0010] Based on the above analysis, the problems and shortcomings of the existing technology are as follows:

[0011] (1) Existing methods that analyze and calculate the crack normal stress to reflect the control effect of the maximum horizontal ground stress on the effectiveness of regional cracks only focus on the influence of ground stress on crack effectiveness under a certain state, without considering the stress change, i.e., the multi-stage problem and the influence of multi-stage stress on the effective crack system.

[0012] (2) There is no data in the existing technology to analyze the influence of multiple periods of geostress on the effective fracture system. Summary of the Invention

[0013] To address the problems existing in the prior art, this invention provides a method and system for determining the effective crack distribution under multi-stage regional tectonic activity.

[0014] This invention is implemented as follows: A method for determining the effective fracture distribution under multi-stage regional tectonic activity includes:

[0015] Based on the fracture characteristics identified by imaging logging data and the current direction of the maximum horizontal stress, a mathematical model is established between the effective fracture distribution and the current direction of the maximum horizontal stress. Based on the distribution map of tectonic stress tracks, the direction of the previous phase of the maximum horizontal stress is identified. The influence of the deflection of the maximum horizontal stress direction on the effective fracture distribution is superimposed, and the degree of opening of the early ineffective fractures by the deflection of the maximum horizontal stress direction is quantitatively determined.

[0016] Furthermore, the method and system for determining the effective fracture distribution under multiple phases of regional tectonic activity includes the following steps:

[0017] Step 1: Based on imaging logging data, identify and vectorize the effective fracture parameters of single wells in areas without significant tectonic deformation, clarify the effective fracture orientation, and statistically analyze and draw the rose diagram of the effective fracture orientation of the target layer in a single well.

[0018] Step 2: Identify the current direction of the maximum principal stress based on the wellbore collapse characteristics of single-well imaging logging data, and identify the direction of the previous secondary maximum principal stress based on the tectonic stress track distribution map.

[0019] Step 3: Match the degree of effective crack development in different structural groups in a certain analysis area with the direction of the maximum principal stress at the current regional tectonic level, and quantitatively analyze the degree of effective crack development in different structural groups.

[0020] Step 4: Draw a rose overlay diagram of the current regional tectonic stress direction and effective fracture orientation in the analysis area to show the overall geostress direction and effective fracture development and distribution characteristics of the analysis area. Determine the influence of the deflection of the maximum principal stress direction to the current maximum principal stress orientation on the effective fracture system and quantify the dominant effective fracture system.

[0021] Furthermore, in step one, based on the azimuth of the straight tail of the tadpole icon in the imaging logging data, a clockwise angular coordinate system is established with true north as the 0-degree azimuth, and the fracture dip data perpendicular to the strike is precisely identified; the validity of the fracture is identified based on the color of the tadpole icon in the imaging logging data, the fracture strike data is calculated, the fracture characteristics of a single well are determined, and a rose diagram of the effective fracture strike of the target layer in a single well is drawn.

[0022] Furthermore, in step two, the orientation of wellbore collapse development is precisely identified based on the direction of the straight line in the elliptical marker icon of wellbore collapse in the imaging logging data, and the direction of the current maximum principal stress is determined.

[0023] Based on the direction of the arrow indicating the maximum horizontal stress in the tectonic stress trajectory distribution map, the location data of the maximum horizontal stress in a certain period are precisely identified to determine the direction of the secondary maximum principal stress in the previous period.

[0024] Furthermore, in step three, it is verified whether the current maximum principal stress direction intersects or overlaps with the effective crack system at a small angle, and when the current maximum principal stress direction is fixed, the proportion of the number of effective cracks in different systems in the total number of effective cracks is determined.

[0025] Furthermore, the quantitative effective fracture dominant group in step four includes: statistically analyzing the proportion of a fracture group whose effectiveness is improved during the geostress deflection process in the effective fracture direction rose diagram, and subtracting the proportion of another fracture group to quantitatively determine the magnitude of the impact of the maximum principal stress direction deflection on the effective fracture group.

[0026] Another object of the present invention is to provide a system for determining the effective fracture distribution under multi-phase regional tectonic activity using the aforementioned method for determining the effective fracture distribution under multi-phase regional tectonic activity. The system for determining the effective fracture distribution under multi-phase regional tectonic activity includes:

[0027] The data input module is used to input the geostress direction for multiple periods;

[0028] The data processing module is used to calculate the proportion of effective fracture group distribution and to quantitatively calculate the effect of deflected in-situ stress on the opening degree of early ineffective fractures.

[0029] The results output module is used to output the final calculation results and result maps.

[0030] Another object of the present invention is to provide a computer device, the computer device including a memory and a processor, the memory storing a computer program, which, when executed by the processor, causes the processor to perform the steps of the method for determining the effective fracture distribution under multi-phase regional tectonic activity.

[0031] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method for determining the effective fracture distribution under multi-phase regional tectonic activity.

[0032] Another objective of this invention is to provide an information data processing terminal for implementing the system for determining the effective fracture distribution under multi-phase regional tectonic activity.

[0033] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows:

[0034] First, addressing the technical problems existing in the prior art and the difficulty of solving them, this paper closely analyzes, in conjunction with the technical solution to be protected by this invention and the results and data obtained during the research and development process, how the technical solution of this invention solves the technical problems, and the inventive technical effects brought about by solving these problems. The specific description is as follows:

[0035] This invention provides a method for determining the distribution of effective fractures under multi-stage regional tectonic activity. Based on fracture characteristics identified from imaging logging data and the current direction of the maximum horizontal stress, a mathematical model is established between the effective fracture distribution and the current direction of the maximum horizontal stress. The influence of the deflection of the maximum horizontal stress direction on the effective fracture distribution is then superimposed, quantitatively determining the degree to which the deflection of the maximum horizontal stress direction affects the opening of early-stage ineffective fractures. Engineering examples provided by this invention demonstrate that, unlike previous methods that simply analyzed the control of stress on fracture effectiveness, this invention analyzes the influence of stress deflection on the effective fracture system.

[0036] Second, considering the technical solution as a whole or from a product perspective, the technical effects and advantages of the technical solution to be protected by this invention are specifically described as follows:

[0037] This invention establishes a system for determining the distribution of effective fractures under multi-stage regional tectonic activity. By inputting the direction parameters of multi-stage geostress, the distribution results of the effective fracture system can be obtained.

[0038] Third, as supplementary evidence of the inventive step of the claims of this invention, it is also reflected in the following important aspects:

[0039] (1) The expected benefits and commercial value of the technical solution of this invention after transformation are as follows:

[0040] After the system of this invention is run, the distribution results of effective fracture groups can be obtained. Based on the dominant effective fracture groups in the distribution results map, and on the principle that effective fractures are the main channels for oil and gas migration, this invention provides a supporting basis for the selection of sweet spots, the selection of well displacement direction, and the establishment of better inter-well connectivity in engineering. It has significant commercial value for increasing oil and gas production and revenue.

[0041] (2) The technical solution of this invention fills a technical gap in the industry both domestically and internationally:

[0042] This invention fills the gap in the study of the influence of geostress deflection on the effective fracture system, and brings the study of the influence of geostress on fracture effectiveness into the dynamic process. That is, it does not only study the influence of current geostress on fracture effectiveness, but also considers the influence of geostress on the distribution of effective fractures in the dynamic process of deflection over time. Attached Figure Description

[0043] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a flowchart of the system operation for determining the effective fracture distribution under multi-phase regional tectonic activity, provided in an embodiment of the present invention.

[0045] Figure 2 This is an imaging logging-fracture related information map of well 1 in a certain analysis area provided in an embodiment of the present invention;

[0046] Figure 3 This is a rose diagram of the effective crack orientation in a certain analysis area provided in an embodiment of the present invention;

[0047] Figure 4 This is an imaging logging-wellbore collapse related information map of well 1 in a certain analysis area provided in an embodiment of the present invention;

[0048] Figure 5 This is a diagram illustrating the coordinated development pattern of regional crack effectiveness and maximum principal stress direction provided by an embodiment of the present invention.

[0049] Figure 6 This is an overlay diagram of the effective crack orientation and the current maximum horizontal geostress direction in a certain analysis area provided by an embodiment of the present invention;

[0050] Figure 7 This is a diagram showing the system operation results of the effective crack orientation in analysis area A provided in this embodiment of the invention;

[0051] Figure 8 This is a diagram showing the system operation results of the effective crack orientation in analysis zone B provided in this embodiment of the invention. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0053] To address the problems existing in the prior art, the present invention provides a method and system for determining the effective crack distribution under multi-stage regional tectonic activity. The present invention will be described in detail below with reference to the accompanying drawings.

[0054] To enable those skilled in the art to fully understand how the present invention is specifically implemented, this section provides an explanatory description of the embodiments that expand upon the technical solutions of the claims.

[0055] like Figure 1 As shown, the method for determining the effective fracture distribution under multi-stage regional tectonic activity provided by this embodiment of the invention includes the following steps:

[0056] S101, input the direction of multi-stage geostress;

[0057] S102, based on imaging logging data, identify fracture characteristics and the current direction of maximum horizontal stress, and establish a mathematical model between the effective fracture distribution and the current direction of maximum horizontal stress.

[0058] S103 calculates the proportion of effective fracture group distribution, quantitatively calculates the effect of deflection stress on the opening degree of early ineffective fractures, and outputs the calculation results and result maps.

[0059] As a preferred embodiment, the method for determining the effective fracture distribution under multi-stage regional tectonic activity provided by this invention specifically includes the following steps:

[0060] Step 1: Based on imaging logging data, identify and vectorize the effective fracture parameters of single wells in areas without significant tectonic deformation, clarify the effective fracture orientation, and statistically analyze and draw a rose diagram of the effective fracture orientation of the target layer in a single well.

[0061] Based on imaging logging data, the effective fracture parameters of single wells in areas without significant tectonic deformation are identified and vectorized to determine the effective fracture orientation. A rose diagram of the effective fracture orientation of the target layer in a single well is then statistically analyzed and drawn.

[0062] Step 2: Identify the current direction of the maximum principal stress based on the wellbore collapse characteristics of single-well imaging logging data, and identify the direction of the previous secondary maximum principal stress based on the tectonic stress track distribution map.

[0063] Step 3: Match the degree of effective crack development in different structural groups in a certain analysis area with the direction of the maximum principal stress at the current regional tectonic level, and quantitatively analyze the degree of effective crack development in different structural groups.

[0064] Step 4: Draw a rose overlay diagram of the current regional tectonic stress direction and effective fracture orientation in the analysis area to show the overall geostress direction and effective fracture development and distribution characteristics of the analysis area. Determine the influence of the deflection of the maximum principal stress direction to the current maximum principal stress orientation on the effective fracture system and quantify the dominant effective fracture system.

[0065] The present invention provides a method for identifying and vectorizing effective fracture parameters in a single well in an area without significant tectonic deformation based on imaging logging data, clarifying the effective fracture orientation, and statistically analyzing and plotting a rose diagram of the effective fracture orientation of the target layer in a single well. This includes: finely identifying fracture dip (perpendicular to strike) data based on the directional direction of the straight tail of the tadpole icon in the imaging logging data (establishing a clockwise angular coordinate system with true north as 0 degrees); identifying the effectiveness of fractures based on the color of the tadpole icon in the imaging logging data; calculating fracture orientation data; determining the fracture characteristics of a single well; and plotting a rose diagram of the effective fracture orientation of the target layer in a single well.

[0066] The present invention provides an embodiment of identifying the current maximum principal stress direction based on the induced fracture and wellbore collapse features of single-well imaging logging data, which includes: accurately identifying the wellbore collapse development azimuth data based on the orientation of the straight line in the wellbore collapse elliptical marker icon in the imaging logging data, and determining the current maximum principal stress direction.

[0067] The method for identifying the direction of the previous period's maximum principal stress based on the distribution map of tectonic stress tracks provided in this embodiment of the invention includes: accurately identifying the azimuth data of the maximum horizontal stress in a certain period based on the direction of the arrow indicating the maximum horizontal stress in the distribution map of tectonic stress tracks, and determining the direction of the previous period's maximum principal stress.

[0068] The present invention provides a method for matching the development degree of effective cracks in different structural directions in a certain analysis area with the current direction of the maximum principal stress at the regional tectonic level, and quantitatively analyzing the development degree of effective cracks in different structural directions. This includes verifying whether the current direction of the maximum principal stress intersects or overlaps with the effective crack structure at a small angle, and determining the proportion of the number of effective cracks in different structural directions in the total number of effective cracks when the current direction of the maximum principal stress is fixed.

[0069] The quantitative effective fracture dominant group provided in this embodiment of the invention includes: statistically analyzing the proportion of a fracture group whose effectiveness is improved during the geostress deflection process in the effective fracture direction rose diagram, and subtracting the proportion of another fracture group to quantitatively determine the magnitude of the influence of the maximum principal stress direction deflection on the effective fracture group.

[0070] The system operation flowchart for determining the effective fracture distribution under multi-stage regional tectonic activity provided in this embodiment of the invention is as follows: Figure 1 As shown, the system specifically includes:

[0071] The data input module is used to input the geostress direction for multiple periods;

[0072] The data processing module is used to calculate the proportion of effective fracture group distribution and to quantitatively calculate the effect of deflected in-situ stress on the opening degree of early ineffective fractures.

[0073] The results output module is used to output the final calculation results and result maps.

[0074] To demonstrate the inventiveness and technical value of the technical solution of this invention, this section provides specific product or related technology application examples of the technical solution claimed.

[0075] As a preferred embodiment, the method for determining the effective fracture distribution under multi-stage regional tectonic activity provided by this invention specifically includes the following steps:

[0076] 1. Based on imaging logging data, identify and vectorize the effective fracture parameters of single wells in areas without significant tectonic deformation, clarify the effective fracture orientation, and statistically analyze and plot the effective fracture orientation rose diagram of the target layer of a single well.

[0077] All single-well imaging logging data for a certain analysis area were identified (see...) Figure 2 This yielded the effective crack depth, dip angle, and dip direction data. After calculating and statistically analyzing the data, a rose diagram of the effective crack orientation was plotted (see...). Figure 3 ).

[0078] 2. Identifying the direction of the current maximum principal stress based on wellbore collapse characteristics using single-well imaging logging data.

[0079] All single-well imaging logging data for a certain analysis area were identified (see...) Figure 4 The wellbore collapse development azimuth in the analysis area was found to be 90 degrees. Since the wellbore collapse azimuth is perpendicular to the current maximum principal stress direction, the current maximum principal stress direction is 180 degrees, forming shear cracks in a conjugate state distributed in the 200-220 degree range and the 140-160 degree range.

[0080] 3. Identify the direction of the previous period's second-maximum principal stress based on the tectonic stress trajectory distribution map.

[0081] The analysis area experienced multiple phases of regional tectonic stress. Based on the distribution map of tectonic stress trajectory, the orientation of the maximum principal stress in the previous phase was determined to be 150 degrees, forming early ineffective shear cracks that exhibited a conjugate state and were distributed in the 110-130 degree range and the 170-190 degree range.

[0082] 4. Integrate the effective fracture groups and horizontal maximum principal stress direction characteristics of all single wells in a certain region, and statistically analyze the development degree of different effective fracture groups affected by regional tectonic factors.

[0083] according to Figure 3 The statistical data can be used to obtain the development degree of different effective crack systems. Specific parameters are shown in Table 1.

[0084] Table 1. Distribution characteristics of all effective cracks in a certain analysis area.

[0085]

[0086]

[0087] 5. Draw a rose overlay diagram of the current tectonic stress direction and effective fracture orientation in the analysis area to show the overall geostress direction and effective fracture development and distribution characteristics of the analysis area. Determine the influence of the previous maximum principal stress direction deflection to the current maximum principal stress orientation on the effective fracture system and quantify the dominant effective fracture system.

[0088] from Figure 3 As can be seen, in the early conjugate shear fractures formed by the previous regional tectonic stress, a group of fully filled fractures with a strike range of 170–190 degrees, related to the stress deflection direction, reopened and became effective after being compressed by the current geostress. Meanwhile, another group of early fractures with a strike range of 110–130 degrees, conjugate to this group, remained closed due to a further approaching 90 degrees to the current geostress and thus experiencing greater normal stress. The diagram illustrates the coordinated development pattern of conjugate fracture effectiveness and the direction of the maximum principal stress. Figure 5 As shown.

[0089] To further quantify the dominant effective fracture group, the current maximum principal stress direction is superimposed as arrows on the effective fracture direction rose diagram to create a superposition diagram. Figure 6 It can be seen that the fracture system related to the current maximum principal stress direction, which has been reopened and distributed in the 170-190 degree range, accounts for 17.9%, while another fracture system conjugate with the reopened fractures and distributed in the 110-130 degree range accounts for 3.0%, resulting in a difference of 14.9%. The early reopened fractures (accounting for 17.9%) are numerically comparable to the effective fractures distributed in the 200-220 degree range (accounting for 17.9%) and the effective fractures distributed in the 140-160 degree range (accounting for 19.4%) formed by current geostress. This shows that the deflection of geostress has a significant effect on the opening of early fractures with relevant orientations and plays a certain role in improving the seepage capacity of the formation.

[0090] Overall, the proportion of effective fracture groups (130-220 degrees) related to the current maximum horizontal stress direction (180 degrees) is 74.6%, which shows the controlling effect of the current maximum horizontal stress direction on the distribution of effective fractures.

[0091] By implementing the invented method, a systematic sample database is established. The system will then be run on analysis area A and analysis area B. After inputting the geostress directions of multiple periods into the system, the system will calculate and process the data to directly obtain the superimposed result map of the effective crack distribution and the current geostress direction in analysis areas A and B.

[0092] The embodiments of the present invention have achieved some positive results during the research and development or use process, and have indeed great advantages compared with the prior art. The following content describes them in conjunction with the data, charts and other information of the experimental process.

[0093] The embodiments of this invention illustrate the operation of the multi-phase regional effective crack distribution analysis system established by this invention through engineering examples, as follows:

[0094] Within analysis area A, the direction of the maximum horizontal geostress in the previous period was 195 degrees, and the direction of the current maximum horizontal geostress is 170 degrees. The results output after data input into the system and processing are as follows: Figure 7 As shown.

[0095] Within analysis area B, the direction of the maximum horizontal geostress in the previous period was 120 degrees, and the direction of the current maximum horizontal geostress is 145 degrees. The results output after data input into the system and processing are as follows: Figure 8 As shown.

[0096] It should be noted that embodiments of the present invention can be implemented in hardware, software, or a combination of both. The hardware portion can be implemented using dedicated logic; the software portion can be stored in memory and executed by a suitable instruction execution system, such as a microprocessor or dedicated-design hardware. Those skilled in the art will understand that the above-described devices and methods can be implemented using computer-executable instructions and / or included in processor control code, for example, such code provided on a carrier medium such as a disk, CD, or DVD-ROM, a programmable memory such as read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and modules of the present invention can be implemented by hardware circuitry such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field-programmable gate arrays, programmable logic devices, etc., or by software executed by various types of processors, or by a combination of the above-described hardware circuitry and software, such as firmware.

[0097] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for determining the effective fracture distribution under multi-stage regional tectonic activity, characterized in that, include: Based on the fracture characteristics identified by imaging logging data and the current direction of the maximum horizontal stress, a mathematical model is established between the effective fracture distribution and the current direction of the maximum horizontal stress. Based on the distribution map of tectonic stress tracks, the direction of the previous phase of the maximum horizontal principal stress was identified; the influence of the deflection of the direction of the maximum horizontal stress on the distribution of effective fractures was superimposed, and the degree of opening of early ineffective fractures by the deflection of the direction of the maximum horizontal stress was quantitatively determined. The method for determining the effective fracture distribution under multiple phases of regional tectonic activity includes the following steps: Step 1: Based on imaging logging data, identify and vectorize the effective fracture parameters of single wells in areas without significant tectonic deformation, clarify the effective fracture orientation, and statistically analyze and draw the rose diagram of the effective fracture orientation of the target layer in a single well. Step 2: Identify the current direction of the maximum principal stress based on the wellbore collapse characteristics of single-well imaging logging data, and identify the direction of the previous secondary maximum principal stress based on the tectonic stress track distribution map. Step 3: Match the degree of effective crack development in different structural groups in a certain analysis area with the direction of the maximum principal stress at the current regional tectonic level, and quantitatively analyze the degree of effective crack development in different structural groups. Step 4: Draw a rose overlay diagram of the current regional tectonic stress direction and effective fracture orientation in the analysis area to show the overall geostress direction and effective fracture development and distribution characteristics of the analysis area, determine the influence of the deflection of the maximum principal stress direction to the current maximum principal stress orientation on the effective fracture system, and quantify the dominant effective fracture system. In step one, based on the azimuth of the straight tail of the tadpole icon in the imaging logging data, a clockwise angular coordinate system is established with due north as the 0-degree azimuth, and the fracture dip data perpendicular to the strike is precisely identified; the validity of the fracture is identified based on the color of the tadpole icon in the imaging logging data, the fracture strike data is calculated, the fracture characteristics of a single well are determined, and a rose diagram of the effective fracture strike of the target layer of a single well is drawn. In step two, the orientation of wellbore collapse development is precisely identified based on the direction of the straight line in the elliptical marker icon of wellbore collapse in the imaging logging data, and the current direction of the maximum principal stress is determined. Based on the direction of the arrow indicating the maximum horizontal stress in the tectonic stress track distribution map, the azimuth data of the maximum horizontal stress in a certain period are precisely identified to determine the direction of the secondary maximum principal stress in the previous period. In step three, it is verified whether the current maximum principal stress direction intersects or overlaps with the effective crack system at a small angle, and when the current maximum principal stress direction is fixed, the proportion of the number of effective cracks in different systems in the total number of effective cracks is determined.

2. The method for determining the effective fracture distribution under multi-stage regional tectonic activity as described in claim 1, characterized in that, Step four involves quantitatively determining the dominant effective fracture group: the percentage of a fracture group whose effectiveness is improved during the geostress deflection process in the effective fracture direction rose diagram, and the difference between this percentage and the percentage of another fracture group, thus quantifying the impact of the maximum principal stress direction deflection on the effective fracture group.

3. A system for determining the effective fracture distribution under multi-stage regional tectonic activity using the method for determining the effective fracture distribution under multi-stage regional tectonic activity as described in any one of claims 1 to 2, characterized in that, Systems for determining the effective fracture distribution under multiple phases of regional tectonic activity include: The data input module is used to input the geostress direction for multiple periods; The data processing module is used to calculate the proportion of effective fracture group distribution and to quantitatively calculate the effect of deflected in-situ stress on the opening degree of early ineffective fractures. The results output module is used to output the final calculation results and result maps.

4. A computer device, characterized in that, The computer device includes a memory and a processor. The memory stores a computer program, which, when executed by the processor, causes the processor to perform the steps of the method for determining the effective fracture distribution under multi-stage regional tectonic activity as described in any one of claims 1 to 2.

5. A computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method for determining the effective fracture distribution under multi-phase regional tectonic activity as described in any one of claims 1 to 2.

6. An information data processing terminal, characterized in that, The information data processing terminal is used to implement the system described in claim 3 for determining the effective fracture distribution under multi-stage regional tectonic activity.

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