Test device for simulating shale damaged casing and test method for simulating shale damaged casing

Abstract

The present invention provides a test device for simulating shale damaged casing and a test method for simulating shale damaged casing. The test device for simulating shale damaged casing includes a sample component, the sample component includes a first shale sample and a second shale sample, the first shale sample and the second shale sample are connected, wherein a first mounting groove is provided on the first shale sample, and a second mounting groove is provided on the second shale sample, and the first mounting groove and the second mounting groove are arranged correspondingly to form a mounting hole; a casing, the casing is arranged in the mounting hole; a first loading system, the first loading system is connected to the sample component to apply a force along a first preset direction to the sample component; a second loading system, the second loading system is connected to the sample component to apply a force along a second preset direction to the sample component. The test device for simulating shale damaged casing of the present invention solves the problem of easy damage of casing in the shale gas exploitation process in the prior art.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas exploitation, and in particular to a test device for simulating shale damaged casing and a test method for simulating shale damaged casing. Background Art

[0002] In the process of shale gas extraction, shear-type casing damage accidents caused by formation slippage occur frequently, which seriously affects the extraction of shale gas. At present, the research on the mechanism of casing damage caused by shale slippage mainly adopts numerical solution and numerical simulation methods, while there are few methods to study formation slippage shear-type casing damage through indoor experimental means. Commonly used experimental methods are as follows: one is to use high-strength expansion agent to simulate the prevention of formation stress shear casing; the second is to use the abnormal similarity theory to solve the problem of limited model size in model test; in addition, there are also direct shear tests on casing under ground conditions.

[0003] However, the conditions set by the above methods are either too idealistic or take too few factors into consideration to simulate the actual underground conditions. The test results have large errors so that the final data does not have much guiding significance for actual operations. Summary of the invention

[0004] The main purpose of the present invention is to provide a test device and a test method for simulating shale damaged casing, so as to solve the problem that the casing is easily damaged during shale gas production in the prior art.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a test device for simulating shale damaged casing is provided, comprising: a sample assembly, the sample assembly comprising a first shale sample and a second shale sample, the first shale sample and the second shale sample are connected, wherein a first mounting groove is provided on the first shale sample, and a second mounting groove is provided on the second shale sample, and the first mounting groove and the second mounting groove are arranged correspondingly to form a mounting hole; a casing, the casing is arranged in the mounting hole; a first loading system, the first loading system is connected to the sample assembly to apply a force along a first preset direction to the sample assembly; a second loading system, the second loading system is connected to the sample assembly to apply a force along a second preset direction to the sample assembly, wherein the second preset direction is perpendicular to the first preset direction.

[0006] Furthermore, the test device for simulating shale damaged casing also includes: an adhesive, which is arranged between the first shale sample and the second shale sample to bond and connect the first shale sample and the second shale sample.

[0007] Furthermore, the first loading system includes a first loading component and a second loading component, the sample component has two oppositely arranged first side surfaces and a second side surface, the first loading component is connected to the first side surface to apply a force to the first side surface, and the second loading component is connected to the second side surface to apply a force to the second side surface.

[0008] Further, the first loading component includes multiple first loading parts, which are respectively connected to different positions on the first side, and the second loading component includes multiple second loading parts, which are respectively connected to different positions on the second side, wherein the multiple first loading parts and the multiple second loading parts are arranged in a one-to-one correspondence.

[0009] Furthermore, the test device for simulating shale damaged casing also includes: a controller, which is connected to the multiple first loading parts and the multiple second loading parts to respectively control each first loading part and each second loading part to apply a force to the sample assembly.

[0010] Furthermore, the test device for simulating shale damaged casing also includes: a third loading system, which is connected to the sample assembly to apply a force to the sample assembly along a third preset direction, wherein the third preset direction is perpendicular to the plane where the first preset direction and the second preset direction are located.

[0011] Furthermore, the test device for simulating shale damaged casing also includes: a water supply component, which is connected to the casing to inject water of a preset pressure into the casing.

[0012] According to another aspect of the present invention, a test method for simulating shale damaged casing is provided, comprising: step S1: bonding a first shale sample and a second shale sample together by adhesive to form a sample assembly, and opening a mounting hole at the connection between the first shale sample and the second shale sample to install the casing; step S2: applying a force to the sample assembly to cause the first shale sample and the second shale sample to slip at the connection to shear the casing in the mounting hole.

[0013] Furthermore, the test method for simulating shale damaged casing also includes step S11 between step S1 and step S2, step S11: applying confining pressure to the sample component in the X-axis direction, Y-axis direction and Z-axis direction, and detecting the displacement change of the sample component in the X-axis direction, Y-axis direction and Z-axis direction.

[0014] Further, in step S2, a force is applied only to the first shale sample or the second shale sample along a first preset direction, and a relative displacement change between the first shale sample and the second shale sample is detected.

[0015] Further, in step S2, a first shear force and a second shear force are respectively applied to a first side surface and a second side surface of the sample component that are opposite to each other, wherein the first shear force and the second shear force are applied in opposite directions and at positions where they are applied are not on the same horizontal plane.

[0016] Furthermore, the test method for simulating shale damaged casing further includes step S10 between step S1 and step S11. Step S10: injecting water of a preset pressure into the casing to simulate a fracturing process of the sample assembly.

[0017] The test device for simulating shale damaged casing using the technical solution of the present invention is used to explore the damage mechanism of shale slip on the casing arranged therein, so as to avoid these damages in advance when designing or installing the casing and protect the casing. Specifically, the test device selects a rectangular sample component and then cuts it diagonally in the diagonal direction to simulate the influence of shale fault on the casing. A mounting hole for installing the casing is provided in the sample component. When cutting, the mounting hole is cut into two parts and respectively located on the first shale sample and the second shale sample. The first loading system and the second loading system simulate the shale around the sample component to apply confining pressure to the sample component, wherein the first loading system applies a pair of forces in opposite directions to the opposite sides of the horizontal position of the sample component along the X-axis, and the second loading system applies a pair of forces in opposite directions to the opposite sides of the horizontal position of the sample component along the Y-axis, thereby applying confining pressure to the four sides of the sample component respectively to simulate the influence of the shale component on the internal casing when it is subjected to horizontal force. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 A connection schematic diagram of an embodiment of a test device for simulating shale damaged casing according to the present invention is shown;

[0020] Figure 2 A partial structural schematic diagram of an embodiment of a test device for simulating shale damaged casing of the present invention is shown;

[0021] Figure 3 A schematic diagram showing unilateral shearing along a first preset direction in a test method for simulating shale damaged casing of the present invention is shown;

[0022] Figure 4 A schematic diagram of double-side shearing along a first preset direction in the test method for simulating shale damaged casing of the present invention is shown.

[0023] The above drawings include the following reference numerals:

[0024] 10. Sample assembly; 11. Mounting hole; 12. First side; 13. Second side; 20. Sleeve; 30. First loading system; 31. First loading assembly; 311. First loading part; 312. First pressure gauge; 32. Second loading assembly; 321. Second loading part; 322. Second pressure gauge; 40. Second loading system; 50. Third loading system; 51. Third pressure gauge; 60. Water supply assembly; 61. Water injection pump; 62. Water supply pressure gauge; 70. Controller; 80. Displacement sensor; 90. Clamp. DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] In order to solve the problem that the casing 20 is easily damaged during shale gas production in the prior art, the present invention provides a test device for simulating shale damaged casing and a test method for simulating shale damaged casing.

[0027] Please refer to Figures 1 to 4 A test device for simulating shale damaged casing includes: a sample component 10, the sample component 10 includes a first shale sample and a second shale sample, the first shale sample and the second shale sample are connected, wherein the first shale sample is provided with a first mounting groove, the second shale sample is provided with a second mounting groove, and the first mounting groove and the second mounting groove are arranged correspondingly to form a mounting hole 11; a casing 20, the casing 20 is arranged in the mounting hole 11; a first loading system 30, the first loading system 30 is connected to the sample component 10 to apply a force along a first preset direction to the sample component 10; a second loading system 40, the second loading system 40 is connected to the sample component 10 to apply a force along a second preset direction to the sample component 10, wherein the second preset direction is perpendicular to the first preset direction.

[0028] The present invention provides a test device for simulating shale damage to casing, so as to explore the damage mechanism of shale sliding on the casing 20 arranged therein, so as to avoid such damage in advance when designing or installing the casing 20 and protect the casing 20. Specifically, the test device selects a rectangular sample component 10, and then cuts it diagonally to simulate the influence of shale fault on the casing 20. The sample component 10 is provided with a mounting hole 11 for installing the casing 20. When cutting, the mounting hole 11 is cut into two parts, and is located at the first page and the second page, respectively. On the shale sample and the second shale sample, the first loading system 30 and the second loading system 40 simulate the shale around the sample component 10 to apply confining pressure to the sample component 10, wherein the first loading system 30 applies a pair of forces in opposite directions to the two opposite sides of the horizontal position of the sample component 10 along the X-axis, and the second loading system applies a pair of forces in opposite directions to the two opposite sides of the horizontal position of the sample component 10 along the Y-axis, thereby applying confining pressure to the four sides of the sample component 10 respectively, so as to simulate the influence of the shale component on the internal casing 20 when it is subjected to horizontal force.

[0029] The test device for simulating shale damaged casing further includes an adhesive, which is disposed between the first shale sample and the second shale sample to bond the first shale sample to the second shale sample.

[0030] In this embodiment, adhesive is used to bond the cut sample assembly 10 together. The adhesive simulates the friction between the two faults when the shale faults move relative to each other. If it is a whole shale assembly, it is impossible to observe the stress condition of the internal casing 20 when a force is applied thereto. If no adhesive is used, the force applied to the first shale sample or the second shale sample directly acts on the casing 20, which cannot simulate the real environment. Therefore, in this embodiment, a suitable adhesive is used to simulate the friction between the faults, and then observe how much shear force is applied to cause damage to the casing 20.

[0031] The first loading system 30 includes a first loading assembly 31 and a second loading assembly 32. The sample assembly 10 has two oppositely disposed first side surfaces 12 and second side surfaces 13. The first loading assembly 31 is connected to the first side surface 12 to apply a force to the first side surface 12, and the second loading assembly 32 is connected to the second side surface 13 to apply a force to the second side surface 13. The first loading assembly 31 includes a plurality of first loading parts 311, and the plurality of first loading parts 311 are respectively connected to different positions on the first side surface 12. The second loading assembly 32 includes a plurality of second loading parts 321, and the plurality of second loading parts 321 are respectively connected to different positions on the second side surface 13, wherein the plurality of first loading parts 311 and the plurality of second loading parts 321 are arranged in a one-to-one correspondence.

[0032] like Figure 2 and Figure 3As shown, the loading methods of the first loading system 30 and the second loading system in this embodiment are basically the same, and the difference lies in the application of force to different positions. Taking the first loading system 30 as an example, the first loading system 30 includes two relatively arranged first loading components 31 and second loading components 32, and each loading component includes three first loading parts 311 in the upper, middle and lower directions along the vertical direction, so as to apply pressure to shale at different heights respectively, so as to simulate the influence of force inside the sample component 10 when shear force is applied to the sample component 10.

[0033] The test device for simulating shale damaged casing further includes a controller 70 , which is connected to the first loading parts 311 and the second loading parts 321 to control each first loading part 311 and each second loading part 321 to apply force to the sample assembly 10 .

[0034] In this embodiment, the test device also includes a controller 70, which is connected to the first loading system 30, the second loading system 40, the third loading system 50 and the water supply assembly 60 to control the pressure of the liquid added to the sleeve 20, and at the same time control the magnitude of the force applied by each loading part on each loading system to the sample assembly 10.

[0035] In addition, each first loading part 311 in the first loading system 30 is provided with a first pressure gauge 312, each loading part in the second loading system 40 is provided with a second pressure gauge 322, and each loading part in the third loading system 50 is provided with a third pressure gauge 51. The water supply component includes a water injection pump 61 and a water supply pressure gauge 62. The controller 70 is respectively controlled and connected to the water injection pump 61, the water supply pressure gauge 62, the first pressure gauge 312, the second pressure gauge 322 and the third pressure gauge 51 to control the entire device.

[0036] The test device for simulating shale damaged casing also includes: a third loading system 50, which is connected to the sample assembly 10 to apply a force to the sample assembly 10 along a third preset direction, wherein the third preset direction is perpendicular to the plane where the first preset direction and the second preset direction are located.

[0037] The third loading system 50 is divided into two parts, the lower part includes a bottom piston, a bottom plug, a displacement assembly and a bottom support, so as to apply pressure to the bottom of the sample assembly 10 to observe the effect on the sleeve 20, and the third preset direction is the vertical Z-axis direction.

[0038] The test device for simulating shale damaged casing further includes a water supply assembly 60 , which is connected to the casing 20 to inject water of a preset pressure into the casing 20 .

[0039] The water supply assembly 60 is used to simulate the pressure of the liquid transported inside the casing 20 during operation, so that the entire test device and environment can reach a real environment, ensuring the reliability of the test results and conclusions.

[0040] The present invention also provides a test method for simulating shale damaged casing, comprising step S1: bonding a first shale sample and a second shale sample together with adhesive to form a sample assembly 10, and opening a mounting hole 11 at the connection between the first shale sample and the second shale sample to install a casing 20; step S2: applying a force to the sample assembly 10 to cause the first shale sample and the second shale sample to slip at the connection to shear the casing 20 in the mounting hole 11.

[0041] The present invention uses the above-mentioned shale damaged casing test device to test the casing 20. When in use, the sample component 10 is first processed, divided and bonded together, and then the casing 20 is inserted into the installation hole 11. Thereafter, a force is applied to the sample component 10, and at the same time, the detection component detects the change of the casing 20 after the force is applied. The detection component of the test device includes a laser scanner, a displacement detector, etc., to detect and analyze the deformation of the sample component 10 and the force applied to the casing 20.

[0042] The test method for simulating shale damaged casing also includes step S11 between step S1 and step S2, step S11: applying confining pressure to the X-axis direction, Y-axis direction and Z-axis direction of the sample component 10, and detecting the displacement change of the sample component 10 in the X-axis direction, Y-axis direction and Z-axis direction. In step S2, only the force along the first preset direction is applied to the first shale sample or the second shale sample, and the relative displacement change between the first shale sample and the second shale sample is detected. In step S2, the first shear force and the second shear force are respectively applied to the first side surface 12 and the second side surface 13 of the sample component 10 that are arranged opposite to each other, wherein the application directions of the first shear force and the second shear force are opposite and the application positions of the first shear force and the second shear force are not on the same horizontal plane.

[0043] In this embodiment, pressure can be applied to the shale sample in steps. According to one method, a force is first applied to the shale sample in the X-axis direction, and then the changes of the sample assembly 10 and the casing 20 are observed. Pressure is applied to the X and Y directions at the same time for detection and observation. Finally, confining pressure is applied to the X, Y and Z directions and observed. In addition, shear force is applied to each direction of the sample assembly 10, such as Figure 3 As shown, the shear force can be applied on one side or on both sides. Figure 4 shown.

[0044] The test method for simulating shale damaged casing further includes step S10 between step S1 and step S11 . Step S10 : injecting water of a preset pressure into the casing 20 to simulate the fracturing process of the sample assembly 10 .

[0045] The water supply assembly 60 includes an injection pump and a water supply pressure gauge. The controller 70 controls the injection pump to inject water into the casing 20 according to a preset pressure value, and the water supply pressure gauge monitors the water pressure in the water supply pipeline in real time.

[0046] The test device in the present invention also includes a plurality of displacement sensors 80, which are respectively connected to the first loading system 30, the second loading system 40 and the third loading system 50 to detect changes in the sample assembly 10 along the directions of the loading forces after the loading systems are pressurized. Taking the first loading system 30 as an example, the first loading system 30 uses hydraulic control pressure to push the loading plate assembly to apply force to the sample assembly 10, wherein the first loading assembly 31 includes a plurality of first loading plates, each of which is provided with a displacement sensor 80, and the second loading assembly 32 includes a plurality of second loading plates, each of which is also provided with a displacement sensor 80, and the displacement sensor 80 determines the volume change of the sample assembly 10 by detecting the displacement change of the corresponding loading plate.

[0047] The first preset direction, the second preset direction and the third preset direction correspond to the X-axis direction, the Y-axis direction and the Z-axis direction respectively.

[0048] The test method for simulating shale damaged casing in the present invention adopts any one of the above-mentioned test devices for simulating shale damaged casing to conduct the test.

[0049] The test method of the present invention comprises: cutting the shale sample obliquely and then gluing it together; placing the fracturing casing 20 into the fracturing cavity of the shale sample, introducing water of preset pressure, and detecting the stress and volume change of the shale sample; applying a first preset stress to the surface of the shale sample along the Z-axis direction, and detecting the stress and volume change of the shale sample; applying a first preset stress to the surface of the shale sample along the Y-axis direction, and detecting the stress and volume change of the shale sample; applying a first preset stress to part of the surface of the shale sample along the X-axis direction, and detecting the stress and volume change of the shale sample;

[0050] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0051] The invention provides a simulation test device for casing damage mechanism caused by shale sliding, comprising a physical model device body, a high-pressure injection system, a confining pressure loading system and a software system.

[0052] The physical model device body includes a casing damage simulation clamp 90 and a disassembly module; the physical model device body is a multi-purpose sample component 10 clamping device that can truly simulate the stress conditions of underground rocks and is used to simulate the non-uniform ground stress of the formation and the reservoir conditions.

[0053] The casing damage simulation clamp 90 includes bolts and nuts, an upper cover, an upper portion of a sample assembly 10, a lower portion of the sample assembly 10, a lower push plate, a bottom piston, a bottom plug, a displacement assembly and a bottom support, and is used to simulate the damage of the casing 20 caused by shear failure during shale sliding. The unique design of the casing damage simulation clamp 90 can realize two shear modes, single shear and double shear, so as to study the damage of the casing 20 under different shear modes. The size of the clamp 90 is 1660mm×1660mm×1800mm, and the specification of the sample assembly 10 is 500mm×500mm×500mm, which can meet the needs of large-size sample assembly 10 experiments.

[0054] The water supply assembly 60 adopts a high-pressure injection system, including a high-precision constant-flow and constant-pressure pump, a pre-boosting pump, a piston container, a manifold unit, and a stress measurement module, which can simulate shale hydraulic fracturing.

[0055] The confining pressure loading system includes a high-precision constant pressure metering pump, which provides a maximum confining pressure of 50 MPa; the high-precision constant pressure metering pump is used for three-way stress loading to provide support for various experimental tests under true triaxial stress conditions; the automatic loading function can be set by a computer, and it has constant pressure and constant current control modes, and the three axial directions can be loaded separately, providing different constant pressure and constant current control modes for the experiment, which is conducive to studying the casing 20 damage caused by shale slippage under different experimental conditions.

[0056] The software system, including data acquisition module and data processing module, can collect data such as pressure, temperature, displacement, flow rate, etc., and realize functions such as 3D process display, data processing, and chart saving.

[0057] The shale slippage-induced casing damage mechanism simulation method of the present invention comprises: applying pressure to a shale sample arranged in a casing damage simulation holder 90 in three directions of x, y and z through a confining pressure loading system to simulate the maximum horizontal ground stress, the minimum horizontal ground stress and the overlying rock formation pressure of the formation; injecting water into a simulated casing 20 arranged in the casing damage simulation holder 90 through a high-pressure injection system to simulate the shale fracturing process; and collecting and processing data through a software system.

[0058] The present application provides a device and method for simulating the mechanism of casing damage caused by shale sliding. The shale sample is placed in a casing damage simulation clamp 90, and shear stresses in different directions are applied by a confining pressure loading system in different directions to simulate the shale shear failure process, thereby studying the relationship between shale sliding shear and casing 20 damage.

[0059] The present invention has the following advantages:

[0060] 1. The casing damage simulation clamp 90 is novel and advanced in design, and can realize multiple shearing functions such as single shearing and left and right double shearing;

[0061] 2. The size of the holder 90 is designed to be larger to meet the needs of the large-size sample assembly 10 experiment and more realistically reflect the actual situation of the formation;

[0062] 3. Equipped with a high-precision constant pressure metering pump, it can realize free conversion between constant pressure and constant current control modes.

[0063] The shale sliding casing damage mechanism simulation device and method of the present invention specifically include the following steps:

[0064] like Figure 3 and Figure 4 , the initial state ensures that the pistons in the casing damage simulation clamp 90 are at the bottom or the outermost edge;

[0065] like Figure 3 and Figure 4 , loading the sample assembly 10 into the casing damage simulation holder 90;

[0066] Open the confining pressure loading system in the Z-axis direction, the pressure can be set, and all pressure and displacement monitoring are maintained;

[0067] Open the confining pressure loading system in the Y-axis direction, the pressure can be set, and all pressure and displacement monitoring are maintained;

[0068] Maintain high and constant pressure in the Z and Y axis confining pressure loading systems, and monitor all pressures and displacements;

[0069] One-sided shearing mode:

[0070] ① Such as Figure 4 , open the confining pressure loading system in the X-axis direction, only open the first loading part 311 at the bottom layer, the pressure can be set, and all pressure and displacement monitoring are maintained;

[0071] ② If Figure 4 , select the constant pressure or constant speed mode of the confining pressure loading system in the X-axis direction, open the first loading part 311, complete the unilateral shearing, the pressure can be set, and keep all pressure and displacement monitoring;

[0072] It should be noted that if the displacement exceeds the set value, shearing stops; pressure displacement is saved in real time;

[0073] Double shear mode:

[0074] Open the confining pressure loading system in the X-axis direction, only open the first loading part 311 at the bottom of the first loading assembly 31 and the first loading part 311 at the top and in the middle of the second loading assembly 32, the pressure can be set, and all pressure and displacement monitoring are maintained;

[0075] It should be noted that if the displacement exceeds the set value, shearing stops; pressure displacement is saved in real time;

[0076] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0077] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0078] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0079] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0080] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A test device for simulating shale damaged casing, characterized in that: include: A sample assembly (10), the sample assembly (10) comprising a first shale sample and a second shale sample, the first shale sample and the second shale sample being connected, wherein the first shale sample is provided with a first mounting groove, the second shale sample is provided with a second mounting groove, the first mounting groove and the second mounting groove are arranged correspondingly in position to enclose a mounting hole (11); A sleeve (20), the sleeve (20) being arranged in the mounting hole (11); A first loading system (30), the first loading system (30) being connected to the sample assembly (10) so as to apply a force along a first preset direction to the sample assembly (10); a second loading system (40), the second loading system (40) being connected to the sample assembly (10) so as to apply a force to the sample assembly (10) along a second preset direction, wherein the second preset direction is perpendicular to the first preset direction; The sample assembly (10) is rectangular, and the sample assembly (10) is cut obliquely along a diagonal direction to form the first shale sample and the second shale sample; the test device for simulating shale damaged casing further comprises: an adhesive, the adhesive being arranged between the first shale sample and the second shale sample to bond and connect the first shale sample and the second shale sample.

2. The test device for simulating shale damaged casing according to claim 1, characterized in that: The first loading system (30) comprises a first loading component (31) and a second loading component (32); the sample component (10) has a first side surface (12) and a second side surface (13) which are arranged opposite to each other; the first loading component (31) is connected to the first side surface (12) to apply a force to the first side surface (12); the second loading component (32) is connected to the second side surface (13) to apply a force to the second side surface (13).

3. The test device for simulating shale damaged casing according to claim 2, characterized in that: The first loading component (31) includes a plurality of first loading parts (311), and the plurality of first loading parts (311) are respectively connected to different positions on the first side surface (12); the second loading component (32) includes a plurality of second loading parts (321), and the plurality of second loading parts (321) are respectively connected to different positions on the second side surface (13), wherein the plurality of first loading parts (311) and the plurality of second loading parts (321) are arranged in a one-to-one correspondence.

4. The test device for simulating shale damaged casing according to claim 3, characterized in that: The test device for simulating shale damaged casing also includes: A controller (70), the controller (70) being connected to the plurality of first loading parts (311) and the plurality of second loading parts (321) so as to respectively control each of the first loading parts (311) and each of the second loading parts (321) to apply a force to the sample assembly (10).

5. The test device for simulating shale damaged casing according to claim 1, characterized in that: The test device for simulating shale damaged casing also includes: A third loading system (50), the third loading system (50) being connected to the sample assembly (10) to apply a force to the sample assembly (10) along a third preset direction, wherein the third preset direction is perpendicular to a plane where the first preset direction and the second preset direction are located.

6. The test device for simulating shale damaged casing according to claim 1, characterized in that: The test device for simulating shale damaged casing also includes: A water supply component (60), the water supply component (60) being connected to the casing (20) so as to inject water of a preset pressure into the casing (20).

7. A test method for simulating shale damage to casing, characterized in that: The test method is a test method of a test device for simulating shale damaged casing according to any one of claims 1 to 6, comprising: Step S1: Adhere a first shale sample and a second shale sample together using adhesive to form a sample assembly (10), and open a mounting hole (11) at the connection between the first shale sample and the second shale sample to install a casing (20); Step S2: applying a force to the sample assembly (10) to cause the first shale sample and the second shale sample to slide at a connection point, thereby shearing the casing (20) in the installation hole (11).

8. The test method for simulating shale damaged casing according to claim 7, characterized in that: The test method for simulating shale damaged casing further includes step S11 between step S1 and step S2. The step S11: applying confining pressure to the sample component (10) in the X-axis direction, the Y-axis direction and the Z-axis direction respectively, and detecting the displacement change of the sample component (10) in the X-axis direction, the Y-axis direction and the Z-axis direction.

9. The test method for simulating shale damaged casing according to claim 8, characterized in that: In the step S2, a force is applied only to the first shale sample or the second shale sample along a first preset direction, and a relative displacement change between the first shale sample and the second shale sample is detected.

10. The test method for simulating shale damaged casing according to claim 8, characterized in that: In step S2, a first shear force and a second shear force are respectively applied to a first side surface (12) and a second side surface (13) of the sample component (10) that are arranged opposite to each other, wherein the first shear force and the second shear force are applied in opposite directions and at positions where they are applied are not on the same horizontal plane.

11. The test method for simulating shale damaged casing according to claim 8, characterized in that: The test method for simulating shale damaged casing further includes step S10 between step S1 and step S11. The step S10: injecting water of a preset pressure into the casing (20) to simulate the fracturing process of the sample assembly (10).

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