Method and device for determining stratum ancient stress direction and electronic equipment

Abstract

The invention provides a method and device for determining the paleo-stress direction of a stratum and electronic equipment. The method comprises the steps that a shale sample and an imaging logging image of the shale sample are obtained, the bedding surface of the shale sample is clear, conjugate shear cracks are developed, the conjugate shear cracks intersect with the bedding surface, and authigenic minerals are filled in the conjugate shear cracks; according to the imaging logging image, the real orientation of the shale sample is restored; determining the original occurrence of the conjugate shear fracture according to the real orientation of the shale sample; determining the formation period of the conjugate shear fracture according to the precipitation time of the authigenic minerals filled in the conjugate shear fracture; and determining the paleo-stress direction of the shale sample in the specific geological historical period according to the original occurrence of the conjugate shear fracture and the formation period of the conjugate shear fracture. The method is high in operability, accurate in result and easier to popularize and apply in the fields of tectonic geology and oil and gas geology.

Description

Technical Field

[0001] The present disclosure relates to the field of geological research, and in particular to a method, device and electronic equipment for determining the direction of paleostress in a stratum. Background Art

[0002] The determination of paleostress direction is a prerequisite for understanding the nature of tectonic activities in geological history, analyzing fault orientation and tectonic deformation mechanisms, and is an important means of reconstructing the regional tectonic evolution history. Existing paleostress direction analysis methods include: based on field outcrop profiles, through fault and joint orientation and fold orientation analysis; or based on indoor microstructural characteristics, such as rock acoustic emission, paleomagnetism, physical simulation and numerical simulation. However, for oil and gas basin reservoirs in deep sea and deep layers that lack field outcrops, drilling cores often lack original orientation information, and existing paleostress direction analysis methods have limitations. Summary of the invention

[0003] The present disclosure provides a method, device, electronic device and storage medium for determining the paleostress direction of a stratum, so as to at least solve the above technical problems existing in the prior art.

[0004] According to a first aspect of the present disclosure, a method for determining the direction of paleostress in a stratum is provided, the method comprising: obtaining a shale sample and an imaging logging image of the shale sample, wherein the shale sample has a clear bedding plane and developed conjugate shear fractures, the conjugate shear fractures intersect the bedding plane, and the conjugate shear fractures are filled with authigenic minerals; restoring the true orientation of the shale sample according to the imaging logging image; determining the original occurrence of the conjugate shear fractures according to the true orientation of the shale sample; determining the formation period of the conjugate shear fractures according to the precipitation time of the authigenic minerals filled in the conjugate shear fractures; determining the formation period of the conjugate shear fractures according to the original occurrence of the conjugate shear fractures and the formation period of .... The method is to determine the ancient stress direction of the shale sample in a specific geological history period; wherein, the original attitude of the conjugate shear fracture is determined according to the true orientation of the shale sample, including: projecting the poles corresponding to the bedding plane of the shale sample and the poles corresponding to the conjugate shear fracture plane onto a stereogram, and a Wu's grid diagram is placed below the stereogram; rotating the Wu's grid diagram clockwise with the strike of the bedding plane as the rotation axis, and the rotation angle is consistent with the angle corresponding to the strike of the bedding plane; moving the pole corresponding to the bedding plane along the latitudinal direction to the center point of the stereogram, restoring the position of the pole corresponding to the original attitude of the conjugate shear fracture on the stereogram, and obtaining the original attitude of the conjugate shear fracture.

[0005] In one possible implementation, restoring the true position of the shale sample based on the imaging logging image includes: placing the shale sample according to preset requirements, rotating the shale sample so that the characteristics of the bedding surface of the shale sample match the characteristics of the imaging logging image, and determining the true position of the shale sample underground.

[0006] In one possible implementation manner, determining the formation period of the conjugate shear fractures according to the precipitation time of the authigenic minerals filling the conjugate shear fractures comprises: determining the precipitation time of the authigenic minerals by mineral dating technology; and determining the formation period of the conjugate shear fractures according to the precipitation time.

[0007] According to a second aspect of the present disclosure, a device for determining the direction of paleostress in a stratum is provided, the device comprising: an acquisition module for acquiring a shale sample and an imaging logging image of the shale sample, wherein the shale sample has a clear bedding plane and developed conjugate shear fractures, the conjugate shear fractures intersect the bedding plane, and the conjugate shear fractures are filled with authigenic minerals; a restoration module for restoring the true orientation of the shale sample according to the imaging logging image; a first determination module for determining the original occurrence of the conjugate shear fracture according to the true orientation of the shale sample; a second determination module for determining the formation period of the conjugate shear fracture according to the precipitation time of the authigenic minerals filled in the conjugate shear fracture; and a third determination module for determining the formation period of the conjugate shear fracture according to the precipitation time of the authigenic minerals filled in the conjugate shear fracture. A block is used to determine the paleostress direction of the shale sample in a specific geological history period according to the original attitude of the conjugate shear fracture and the formation period of the conjugate shear fracture; wherein the first determination module is specifically used to project the poles corresponding to the bedding plane of the shale sample and the poles corresponding to the conjugate shear fracture plane onto a stereogram, and a Wu's grid diagram is placed below the stereogram; the Wu's grid diagram is rotated clockwise with the strike of the bedding plane as the rotation axis, and the rotation angle is consistent with the angle corresponding to the strike of the bedding plane; the pole corresponding to the bedding plane is moved along the latitudinal direction to the center point of the stereogram, and the pole corresponding to the original attitude of the conjugate shear fracture is restored to the position of the pole corresponding to the original attitude of the conjugate shear fracture on the stereogram to obtain the original attitude of the conjugate shear fracture.

[0008] In one possible implementation, the restoration module is specifically used to place the shale sample according to preset requirements, rotate the shale sample, match the characteristics of the bedding surface of the shale sample with the characteristics of the imaging logging image, and determine the true position of the shale sample underground.

[0009] In one embodiment, the second determination module includes: a first determination submodule for determining the precipitation time of the authigenic mineral by mineral dating technology; and a second determination submodule for determining the formation period of the conjugate shear fracture according to the precipitation time.

[0010] According to a third aspect of the present disclosure, there is provided an electronic device, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method described in the present disclosure.

[0011] According to a fourth aspect of the present disclosure, a non-transitory computer-readable storage medium storing computer instructions is provided, wherein the computer instructions are used to cause the computer to execute the method described in the present disclosure.

[0012] The present invention discloses a method, device, electronic device and storage medium for determining the paleostress direction of a stratum. First, a mudstone sample with clear bedding plane and developed conjugate shear fractures is obtained, and the conjugate shear fractures intersect with the bedding plane, and the conjugate shear fractures are filled with authigenic minerals, and an imaging logging image corresponding to the mudstone sample is obtained. The original occurrence of the conjugate shear fractures of the mudstone sample is determined based on the imaging logging image. The conjugate shear fractures record paleostress information, so the paleostress direction of the mudstone sample can be determined by analyzing the original occurrence of the conjugate shear fractures; in addition, the mudstone sample is filled with authigenic minerals, and the authigenic minerals contain information such as geological historical periods. By analyzing the authigenic minerals, the historical period corresponding to the mudstone sample can be determined. The application of this method can overcome the limitations of paleostress direction analysis caused by the lack of original orientation information and other information of field geological outcrops and drilling cores, has strong operability, relatively accurate results, and is easier to promote and apply in the fields of structural geology and oil and gas geology.

[0013] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The above and other objects, features and advantages of the exemplary embodiments of the present disclosure will become readily understood by reading the detailed description below with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present disclosure are shown in an exemplary and non-limiting manner, in which: In the drawings, the same or corresponding reference numerals represent the same or corresponding parts.

[0015] Figure 1 A schematic diagram of the implementation process of a method for determining the paleostress direction of a stratum according to an embodiment of the present disclosure is shown; Figure 2The schematic diagram shows the process of determining the original occurrence of conjugate shear cracks according to the embodiment of the present disclosure. Figure 1 ; Figure 3 The schematic diagram shows the process of determining the original occurrence of conjugate shear cracks according to the embodiment of the present disclosure. Figure 2 ; Figure 4 The schematic diagram shows the process of determining the original occurrence of conjugate shear cracks according to the embodiment of the present disclosure. Figure 3 ; Figure 5 The schematic diagram shows the process of determining the original occurrence of conjugate shear cracks according to the embodiment of the present disclosure. Figure 4 ; Figure 6 A schematic diagram of a shale sample before the conjugate shear fracture of the embodiment of the present disclosure is restored to its original state Figure 1 ; Figure 7 A schematic diagram of a shale sample before the conjugate shear fracture of the embodiment of the present disclosure is restored to its original state Figure 2 ; Figure 8 A schematic diagram showing feature matching between a bedding plane of a shale sample and an imaging logging image according to an embodiment of the present disclosure is shown; Fig. 9 A schematic diagram of a module of a device for determining paleostress direction of a stratum according to an embodiment of the present disclosure is shown; Fig.10 A schematic diagram of the structure of an electronic device according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0016] In order to make the purpose, features, and advantages of the present disclosure more obvious and easy to understand, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0017] Figure 1 A schematic diagram of the implementation flow of a method for determining paleostress direction of a stratum according to an embodiment of the present disclosure is shown.

[0018] See also Figure 1According to the first aspect of the embodiment of the present disclosure, a method for determining the paleostress direction of a formation is provided, the method comprising: step 101, obtaining a shale sample and an imaging logging image of the shale sample, the shale sample having a clear bedding plane and developed conjugate shear fractures, the conjugate shear fractures intersecting the bedding plane, and the conjugate shear fractures being filled with authigenic minerals; step 102, restoring the true position of the shale sample according to the imaging logging image; step 103, determining the original occurrence of the conjugate shear fractures according to the true position of the shale sample; step 104, determining the formation period of the conjugate shear fractures according to the precipitation time of the authigenic minerals filled in the conjugate shear fractures; step 105, determining the paleostress direction of the shale sample in a specific geological history period according to the original occurrence of the conjugate shear fractures and the formation period of the conjugate shear fractures.

[0019] The present application first obtains a mud shale sample, which is obtained by drilling and collection, and simultaneously obtains an imaging logging image of the mud shale sample. The imaging logging image is obtained by a specific logging technology, and reflects the physical parameter distribution of the well wall or objects around the well. The selected mud shale sample has a clear bedding plane and developed conjugate shear fractures. The bedding plane is caused by environmental changes or changes in sedimentation during the sedimentation process; the conjugate shear fractures are cracks formed by stress fractures in rocks, usually manifested as two sets of intersecting shear planes, and the development degree of the two sets of fractures may be unbalanced. The present application selects a group with more developed conjugate shear fractures, and the conjugate shear fractures in the mud shale sample selected by the present application intersect with the bedding plane. The conjugate shear fractures are filled with authigenic minerals, which can be calcite, dolomite quartz, etc. The mineral type of the authigenic minerals is not specific.

[0020] During the drilling and collection process, the orientation of the shale sample will change, so the collected shale sample is matched with its corresponding imaging logging image to restore the true orientation of the shale sample underground. After determining the true orientation of the shale sample underground, the original occurrence of the conjugate shear fracture on the shale sample can be determined. Since the conjugate shear fracture is a fracture formed by the stress fracture of the rock, the direction of the stress on the shale sample can be determined according to the original occurrence of the conjugate shear fracture. The direction of the acute angle of the conjugate shear fracture in the original occurrence of the conjugate shear fracture is the direction of the stress on the shale sample. In addition, since the shale sample is subjected to shear stress during the geological tectonic process to form conjugate shear fractures, these fractures will be filled with authigenic minerals later, so the formation period of the conjugate shear fracture can be determined according to the precipitation time of the authigenic minerals filled in the conjugate shear fracture. Finally, the paleo-stress direction of the shale sample in a specific geological history period is determined according to the paleo-stress direction determined by the original occurrence of the conjugate shear fracture and the formation period of the conjugate shear fracture.

[0021] Furthermore, the original attitude of the conjugate shear fracture is determined according to the true orientation of the shale sample, including: projecting the poles corresponding to the bedding plane of the shale sample and the poles corresponding to the conjugate shear fracture plane onto the stereogram, with a Wu's grid diagram placed below the stereogram; rotating the Wu's grid diagram clockwise with the strike of the bedding plane as the rotation axis, and the rotation angle is consistent with the angle corresponding to the strike of the bedding plane; moving the pole corresponding to the bedding plane along the latitudinal direction to the center point of the stereogram, restoring the position of the pole corresponding to the original attitude of the conjugate shear fracture on the stereogram, and obtaining the original attitude of the conjugate shear fracture.

[0022] like Figure 2-Figure 5 As shown, Figure 2 The figure shows the projection of the pole A corresponding to the bedding plane and the pole B corresponding to the conjugate shear fracture plane onto the stereogram. The Wu's network diagram is placed below the stereogram. Figure 3 As shown in the figure, take the direction of the bedding plane as the rotation axis, rotate the Wu's grid diagram clockwise, where the rotation angle is consistent with the angle corresponding to the direction of the bedding plane, rotate the bedding plane to a horizontal state, and finally Figure 4 and Figure 5 As shown in the figure, the pole corresponding to the bedding plane is moved along the latitudinal direction to the center point of the stereogram. When the pole corresponding to the bedding plane moves, the pole corresponding to the conjugate shear fracture plane also moves accordingly. When the pole of the bedding plane moves to the center of the stereogram, the position of the pole corresponding to the conjugate shear fracture plane is determined to be the position of the pole corresponding to the original attitude of the conjugate shear fracture in the stereogram. Figure 5 Middle point , and finally the original occurrence of the conjugate shear crack is obtained.

[0023] Figure 6 Schematic diagram of a shale sample before the conjugate shear fractures return to their original state Figure 1 , Figure 7 Schematic diagram of a shale sample showing the restoration of the original orientation of the conjugate shear fracture Figure 2 .like Figure 6 and Figure 7 As shown in Figure 2, Fa and Fb are conjugate shear fractures of shale samples. The arrow points to the paleostress direction of the shale sample determined based on the original occurrence of the conjugate shear fractures. The present application first obtains the shale sample and its corresponding imaging logging image, and restores the true position of the shale sample underground based on the imaging logging image, so as to further determine the original occurrence of the conjugate shear fractures on the shale sample, and determine the formation period of the conjugate shear fractures based on the precipitation time of the authigenic minerals filling the conjugate shear fractures, and finally determine the paleostress direction of the shale sample in a specific geological history period based on the original occurrence of the conjugate shear fractures and the formation period of the conjugate shear fractures. The application of this method can overcome the problem of limited analysis of paleostress direction caused by the lack of original orientation information and other information on field geological outcrops and drilling cores, and it has strong operability and relatively accurate results.

[0024] Figure 8 A schematic diagram showing feature matching between the bedding plane of a shale sample and an imaging logging image according to an embodiment of the present disclosure is shown.

[0025] like Figure 8 As shown, based on the imaging logging image, the true position of the shale sample is restored, including: placing the shale sample according to preset requirements, rotating the shale sample so that the characteristics of the bedding surface of the shale sample match the characteristics of the imaging logging image, and determining the true position of the shale sample underground.

[0026] The shale sample is placed at 90° perpendicular to the horizontal plane, and then the shale sample is rotated to match the dip information and inclination information of the shale sample bedding plane with the bedding plane information of the imaging logging image corresponding to the depth position of the shale sample. The position corresponding to the matching result is the true position of the shale sample underground. Figure 8 In the process, the shale sample is first placed vertically to the horizontal plane and then rotated so that the dip and inclination information of the bedding plane after the bedding plane is unfolded matches the bedding plane information of the imaging logging image at the corresponding depth position.

[0027] In one possible implementation, the formation period of the conjugate shear fractures is determined according to the precipitation time of the authigenic minerals filling the conjugate shear fractures, including: determining the precipitation time of the authigenic minerals by mineral dating technology; determining the formation period of the conjugate shear fractures according to the precipitation time.

[0028] The present application can detect authigenic minerals through mineral dating technology to determine the precipitation time of authigenic minerals, and determine the precipitation time as the formation period of conjugate shear cracks. Among them, when the authigenic mineral is calcite or dolomite, the uranium-lead dating technology can be used to determine the precipitation time of calcite or dolomite, and when the authigenic mineral is quartz, the rubidium-strontium dating technology can be used to determine the precipitation time of quartz. Uranium-lead dating technology and rubidium-strontium dating technology have high accuracy, and the formation period of conjugate shear cracks determined by the present application using uranium-lead dating technology and rubidium-strontium dating technology is more accurate.

[0029] Fig. 9 A module schematic diagram of a device for determining paleostress direction of a stratum according to an embodiment of the present disclosure is shown.

[0030] See also Fig. 9 According to a second aspect of the present disclosure, a device for determining the direction of paleostress in a stratum is provided, the device comprising: an acquisition module 901, for acquiring a shale sample and an imaging logging image of the shale sample, wherein the shale sample has a clear bedding plane and developed conjugate shear fractures, the conjugate shear fractures intersect the bedding plane, and the conjugate shear fractures are filled with authigenic minerals; a restoration module 902, for restoring the true orientation of the shale sample according to the imaging logging image; a first determination module 903, for determining the original occurrence of the conjugate shear fracture according to the true orientation of the shale sample; a second determination module 904, for determining the formation period of the conjugate shear fracture according to the precipitation time of the authigenic minerals filled in the conjugate shear fracture; and a third determination module 905, for determining the formation period of the conjugate shear fracture according to the precipitation time of the authigenic minerals filled in the conjugate shear fracture. Module 905 is used to determine the paleostress direction of the shale sample in a specific geological history period according to the original attitude of the conjugate shear fracture and the formation period of the conjugate shear fracture; the first determination module is specifically used to project the poles corresponding to the bedding plane of the shale sample and the poles corresponding to the conjugate shear fracture plane onto a stereogram, and a Wu's grid diagram is placed below the stereogram; the Wu's grid diagram is rotated clockwise with the strike of the bedding plane as the rotation axis, and the rotation angle is consistent with the angle corresponding to the strike of the bedding plane; the pole corresponding to the bedding plane is moved along the latitudinal direction to the center point of the stereogram, and the position of the pole corresponding to the original attitude of the conjugate shear fracture is restored to the position of the stereogram to obtain the original attitude of the conjugate shear fracture.

[0031] In one embodiment, the restoration module 902 is specifically used to place the shale sample according to preset requirements, rotate the shale sample, match the characteristics of the bedding surface of the shale sample with the characteristics of the imaging logging image, and determine the true position of the shale sample underground.

[0032] In one embodiment, the second determination module 904 includes: a first determination submodule 9041 for determining the precipitation time of authigenic minerals by mineral dating technology; and a second determination submodule 9042 for determining the formation period of conjugate shear fractures according to the precipitation time.

[0033] According to an embodiment of the present disclosure, the present disclosure also provides an electronic device and a readable storage medium.

[0034] Fig.10 A schematic block diagram of an example electronic device 1000 that can be used to implement an embodiment of the present disclosure is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present disclosure described and / or required herein.

[0035] like Fig.10 As shown, the device 1000 includes a computing unit 1001, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 1002 or a computer program loaded from a storage unit 1008 into a random access memory (RAM) 1003. In the RAM 1003, various programs and data required for the operation of the device 1000 can also be stored. The computing unit 1001, the ROM 1002, and the RAM 1003 are connected to each other via a bus 1004. An input / output (I / O) interface 1005 is also connected to the bus 1004.

[0036] A number of components in the device 1000 are connected to the I / O interface 1005, including: an input unit 1006, such as a keyboard, a mouse, etc.; an output unit 1007, such as various types of displays, speakers, etc.; a storage unit 1008, such as a disk, an optical disk, etc.; and a communication unit 1009, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 1009 allows the device 1000 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0037] The computing unit 1001 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 1001 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 1001 performs the various methods and processes described above, such as a method for determining the direction of paleo-stress in a formation. For example, in some embodiments, a method for determining the direction of paleo-stress in a formation may be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as a storage unit 1008. In some embodiments, part or all of the computer program may be loaded and / or installed on the device 1000 via the ROM 1002 and / or the communication unit 1009. When the computer program is loaded into the RAM 1003 and executed by the computing unit 1001, one or more steps of the method for determining the direction of paleo-stress in a formation described above may be performed. Alternatively, in other embodiments, the computing unit 1001 may be configured to execute a method for determining paleostress direction of a formation in any other appropriate manner (eg, by means of firmware).

[0038] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0039] The program code for implementing the method of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0040] In the context of the present disclosure, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0041] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0042] The systems and techniques described herein may be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), and the Internet.

[0043] A computer system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The relationship of client and server is generated by computer programs running on respective computers and having a client-server relationship with each other. The server may be a cloud server, a server of a distributed system, or a server combined with a blockchain.

[0044] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and this document does not limit this.

[0045] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present disclosure, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0046] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A method for determining the direction of paleostress in a stratum, characterized in that: The method comprises: Obtaining a shale sample and an imaging logging image of the shale sample, wherein the shale sample has a clear bedding plane and developed conjugate shear fractures, the conjugate shear fractures intersect the bedding plane, and the conjugate shear fractures are filled with authigenic minerals; Restoring the true position of the shale sample according to the imaging logging image; Determining the original occurrence of the conjugate shear fracture according to the true orientation of the shale sample; Determining the formation period of the conjugate shear fracture according to the precipitation time of the authigenic minerals filling the conjugate shear fracture; Determining the paleostress direction of the shale sample in a specific geological history period according to the original occurrence of the conjugate shear fractures and the formation period of the conjugate shear fractures; Among them, determining the original attitude of the conjugate shear fracture according to the true orientation of the shale sample includes: projecting the poles corresponding to the bedding plane of the shale sample and the poles corresponding to the conjugate shear fracture plane onto a stereographic map, with a Wu's grid map placed below the stereographic map; rotating the Wu's grid map clockwise with the strike of the bedding plane as the rotation axis, and the rotation angle is consistent with the angle corresponding to the strike of the bedding plane; moving the pole corresponding to the bedding plane along the latitudinal direction to the center point of the stereographic map, restoring the position of the pole corresponding to the original attitude of the conjugate shear fracture on the stereographic map, and obtaining the original attitude of the conjugate shear fracture.

2. The method according to claim 1, characterized in that The method of restoring the true position of the shale sample according to the imaging logging image comprises: The shale sample is placed according to preset requirements, and the shale sample is rotated so that the characteristics of the bedding surface of the shale sample match the characteristics of the imaging logging image, and the true position of the shale sample underground is determined.

3. The method according to claim 1, characterized in that: The step of determining the formation period of the conjugate shear fractures according to the precipitation time of the authigenic minerals filling the conjugate shear fractures comprises: Determine the precipitation time of the authigenic mineral by mineral dating technology; The formation period of the conjugate shear cracks is determined according to the precipitation time.

4. A device for determining the direction of paleostress in a stratum, characterized in that: The device comprises: An acquisition module, used for acquiring a shale sample and an imaging logging image of the shale sample, wherein the shale sample has a clear bedding plane and developed conjugate shear fractures, the conjugate shear fractures intersect the bedding plane, and the conjugate shear fractures are filled with authigenic minerals; A restoration module, used to restore the true position of the shale sample according to the imaging logging image; A first determination module is used to determine the original occurrence of the conjugate shear fracture according to the true orientation of the shale sample; A second determination module is used to determine the formation period of the conjugate shear fracture according to the precipitation time of the authigenic minerals filling the conjugate shear fracture; A third determination module is used to determine the paleostress direction of the shale sample in a specific geological history period according to the original occurrence of the conjugate shear fracture and the formation period of the conjugate shear fracture; Among them, the first determination module is specifically used to project the poles corresponding to the bedding plane of the shale sample and the poles corresponding to the conjugate shear fracture surface onto the stereogram, and a Wu's grid diagram is placed below the stereogram; the Wu's grid diagram is rotated clockwise with the strike of the bedding plane as the rotation axis, and the rotation angle is consistent with the angle corresponding to the strike of the bedding plane; the pole corresponding to the bedding plane is moved along the latitudinal direction to the center point of the stereogram, and the position of the pole corresponding to the original attitude of the conjugate shear fracture is restored to the position of the stereogram, so as to obtain the original attitude of the conjugate shear fracture.

5. The device according to claim 4, characterized in that The restoration module is specifically used to place the shale sample according to preset requirements, rotate the shale sample, match the characteristics of the bedding surface of the shale sample with the characteristics of the imaging logging image, and determine the true position of the shale sample underground.

6. The device according to claim 4, characterized in that The second determining module includes: A first determination submodule is used to determine the precipitation time of the authigenic mineral by using mineral dating technology; The second determination submodule is used to determine the formation period of the conjugate shear crack according to the precipitation time.

7. An electronic device, characterized in that: include: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 3.

8. A non-transitory computer-readable storage medium storing computer instructions, characterized in that: The computer instructions are used to make a computer execute the method according to any one of claims 1-3.

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