Sleeve shape determination method and device

Abstract

The invention provides a casing form determination method and device.The method comprises the steps that an initial finite element model is constructed according to a model structure, material parameters and a contact relation of influence factors of deformation of a target casing during horizontal fracturing of a target reservoir; performing grid division on a fractured hanging wall stratum, a fractured footwall stratum, a cement sheath and a target casing in the initial finite element model, and setting a loading mode of displacement loading boundaries of the fractured hanging wall stratum and the fractured footwall stratum as a displacement attenuation loading mode to form a target finite element model; executing a simulation task through the target finite element model to obtain a simulation result; and determining the deformation state of the target casing pipe according to the simulation result. According to the scheme, the shear compression deformation form of the casing pipe can be accurately determined, so that the deformation prevention and control direction of the casing pipe is determined, and through-well fracture in the hydraulic fracturing process is prevented from being activated.

Description

Technical Field

[0001] The present invention relates to the field of horizontal fracturing, and more particularly to a method and device for determining casing morphology. Background Art

[0002] Casing deformation often occurs during the development of unconventional oil and gas using horizontal well hydraulic fracturing technology. Casing deformation is mainly caused by the injection of fracturing fluid, which leads to an increase in fluid pressure in the well fracture, inducing shear slippage in the well fracture, resulting in asymmetric squeezing of the casing by the two formations, which in turn causes casing deformation. Casing deformation during fracturing construction will make it impossible to seal the bridge plug of the subsequent fracturing section in place, resulting in the problem of multiple sections being compressed or even lost, which will not only affect the effect of horizontal well volume transformation, increase the construction time and difficulty, but also affect the overall economic benefits of unconventional oil and gas resource development. Therefore, the problem of casing deformation has once become a hot issue in the field of unconventional oil and gas resource development in recent years.

[0003] In order to effectively prevent and control casing deformation, it is crucial to accurately determine the form of casing shear deformation. At present, multi-arm caliper logging is usually used to directly determine the form of casing deformation, and finite element numerical simulation software is used to simulate and invert the form of casing shear deformation. However, in the existing simulation of casing deformation using finite element numerical simulation software, when a fault slip causes casing deformation, it is assumed that only one plate of the fractured formation is displaced, while the other plate of the fractured formation is fixed, and the displacements of the two fractured formations are equal. Although this idea can simulate the local shear deformation characteristics of the casing, the overall deformation form of the simulated casing is far from the actual deformation form of the casing.

[0004] As to how to accurately determine the deformation shape of the casing, no effective solution has been proposed so far. Summary of the invention

[0005] The purpose of the present application is to provide a method and device for determining the shape of a casing, which achieves the effect of accurately determining the shape of the casing deformation by setting reasonable boundary conditions of a finite element model of casing deformation.

[0006] This specification provides a method and device for determining the sleeve morphology, which is implemented as follows:

[0007] A method for determining a casing morphology, comprising:

[0008] Obtaining the model structure, material parameters and contact relationship of the influencing factors of the target casing deformation during horizontal fracturing of the target reservoir, wherein the influencing factors include: the upper wall formation of the fracture, the lower wall formation of the fracture, the cement sheath and the target casing;

[0009] An initial finite element model is constructed according to the model structure, material parameters and contact relationship of the influencing factors of the target casing deformation during horizontal fracturing of the target reservoir;

[0010] Meshing the fracture upper wall strata, the fracture lower wall strata, the cement sheath and the target casing in the initial finite element model, and setting the loading mode of the displacement loading boundary of the fracture upper wall strata and the fracture lower wall strata to a displacement attenuation loading mode, so as to form a target finite element model;

[0011] Performing a simulation task through the target finite element model to obtain a simulation result;

[0012] The deformation state of the target casing is determined according to the simulation result.

[0013] In one embodiment, the displacement loading boundary of the fractured upper wall strata includes: an upper boundary and a lower boundary of the fractured upper wall strata, and the displacement loading boundary of the fractured lower wall strata includes: an upper boundary and a lower boundary of the fractured lower wall strata.

[0014] In one embodiment, the model structure includes: size, strike and dip of the fracture between the upper plate formation and the lower plate formation; material parameters include: Young's modulus, Poisson's ratio and yield strength; contact relationships include: contact relationship between the upper plate formation and the lower plate formation, contact relationship between the upper plate formation and the cement sheath, contact relationship between the lower plate formation and the cement sheath, and contact relationship between the cement sheath and the target casing.

[0015] In one embodiment, meshing the fracture upper wall formation, the fracture lower wall formation, the cement sheath and the target casing in the initial finite element model includes:

[0016] Setting the grid division mode of the first part of the target casing and the first part of the cement sheath to a non-uniform encryption mode, wherein the first part of the target casing is the casing area within a preset range on both sides of the fracture surface of the horizontal fracturing, and the first part of the cement sheath is the cement sheath area within a preset range on both sides of the fracture surface of the horizontal fracturing;

[0017] Determine the maximum network node spacing and the minimum network node spacing of the non-uniform encryption mode;

[0018] The grid division mode of the upper wall stratum of the fracture, the lower wall stratum of the fracture, the second part of the target casing and the second part of the cement sheath is set to a uniform division mode, wherein the second part of the target casing is the casing area outside the preset range on both sides of the fracture surface of the horizontal fracturing, and the second part of the cement sheath is the cement sheath area outside the preset range on both sides of the fracture surface of the horizontal fracturing;

[0019] Determine the grid node spacing for uniform partitioning pattern;

[0020] According to the determined maximum and minimum network node spacings of the non-uniform encryption mode and the grid node spacings of the uniform division mode, the fault upper wall strata, the fault lower wall strata, the cement sheath and the target casing are gridded.

[0021] In one embodiment, the displacement attenuation loading mode is that the fractured upper plate strata and the fractured lower plate strata slide in a direction parallel to the fracture surface of the horizontal fracturing. At corresponding points symmetrical about the center of the fracture surface of the horizontal fracturing, the displacements of the fractured upper plate strata and the fractured lower plate strata are equal in magnitude and opposite in direction, and the displacement loading boundary of the sliding of the fractured upper plate strata and the fractured lower plate strata produces displacement attenuation within the displacement attenuation distance, and the displacement is 0 outside the displacement attenuation distance, wherein the displacement attenuation distance is the horizontal distance between the fracture surface of the horizontal fracturing and the point where the formation displacement attenuates to 0.

[0022] In one embodiment, the loading mode of the displacement loading boundary of the fracture upper wall strata and the fracture lower wall strata is set to a displacement attenuation loading mode, including:

[0023] Establish a local coordinate system with the center point of the fracture surface as the origin as the target coordinate system;

[0024] Determine the attenuation law of the displacement loading boundary of the fault hanging wall strata and the fault footwall strata;

[0025] According to the attenuation law of the displacement loading boundary, a displacement attenuation function of the displacement loading boundary of the upper plate stratum of the fracture and the lower plate stratum of the fracture is set on the target coordinate system, wherein the displacement attenuation function includes: a linear displacement attenuation function and a quadratic function attenuation function;

[0026] Normal constraints are set on the boundaries other than the displacement loading boundaries of the fracture upper wall formation and the fracture lower wall formation, the first end and the second end of the cement ring, and the first end and the second end of the target casing.

[0027] In one embodiment, the linear displacement attenuation function is expressed as:

[0028]

[0029] Wherein, D(x, y, z) is the displacement attenuation function, x is the coordinate on the horizontal axis of the target coordinate system, y is the coordinate on the vertical axis of the target coordinate system, z is the coordinate on the vertical axis of the target coordinate system, D0 is the displacement of the displacement loading boundary of the upper wall formation and the lower wall formation of the fault at the fracture surface of the horizontal fracturing, x0 is the displacement attenuation distance, and α is the angle between the fault strike and the well trajectory; is the inclination angle of the fracture, L is the length of the entire target finite element model, W is the width of the entire target finite element model, and H is the height of the entire target finite element model.

[0030] A casing morphology determination device, comprising:

[0031] An acquisition module is used to acquire the model structure, material parameters and contact relationship of the influencing factors of the target casing deformation during horizontal fracturing of the target reservoir, wherein the influencing factors include: fracture upper wall formation, fracture lower wall formation, cement sheath and target casing;

[0032] The first forming module is used to construct an initial finite element model according to the model structure, material parameters and contact relationship of the influencing factors of the target casing deformation during horizontal fracturing of the target reservoir;

[0033] The second forming module is used to mesh the fracture upper wall formation, the fracture lower wall formation, the cement sheath and the target casing in the initial finite element model, and set the loading mode of the displacement loading boundary of the fracture upper wall formation and the fracture lower wall formation to the displacement attenuation loading mode to form a target finite element model;

[0034] An execution module, used to execute the simulation task through the target finite element model to obtain a simulation result;

[0035] A determination module is used to determine the deformation state of the target casing according to the simulation result.

[0036] An electronic device comprises a processor and a memory for storing instructions executable by the processor, wherein the processor implements the steps of any one of the above methods when executing the instructions.

[0037] A computer-readable storage medium stores computer instructions, which, when executed by a processor, implement the steps of any of the above methods.

[0038] The present application provides a method and device for determining casing morphology, by obtaining the model structure, material parameters and contact relationship of the influencing factors of the deformation of the target casing during horizontal fracturing of the target reservoir, wherein the influencing factors include: fracture upper plate formation, fracture lower plate formation, cement ring and target casing; constructing an initial finite element model according to the model structure, material parameters and contact relationship of the influencing factors of the deformation of the target casing during horizontal fracturing of the target reservoir; meshing the fracture upper plate formation, fracture lower plate formation, cement ring and target casing in the initial finite element model, and setting the loading mode of the displacement loading boundary of the fracture upper plate formation and the fracture lower plate formation to the displacement attenuation loading mode to form a target finite element model; performing simulation tasks through the target finite element model to obtain simulation results; determining the deformation state of the target casing according to the simulation results. The above scheme can realize the accurate determination of the shear and compression deformation morphology of the casing, thereby determining the direction of casing deformation prevention and control, and preventing the activation of the through-well fracture during hydraulic fracturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of this specification, the drawings required for use in the embodiments will be briefly introduced below. The drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 is a method flow chart of an embodiment of the method for determining the sleeve morphology provided by the present application;

[0041] Figure 2 is a schematic diagram of a displacement attenuation mode of a displacement loading boundary provided by the present application;

[0042] Figure 3 This is a structural diagram of an initial finite element model of an embodiment of a method for determining a casing shape provided by the present application;

[0043] Figure 4 It is a schematic diagram of stratigraphic division of an embodiment of a casing morphology determination method provided by the present application;

[0044] Figure 5 It is a cement ring division schematic diagram of an embodiment of the casing morphology determination method provided by the present application;

[0045] Figure 6 This is a schematic diagram of casing division according to an embodiment of a casing morphology determination method provided by the present application;

[0046] Figure 7 It is a local morphological feature diagram of a casing according to a simulation result of an embodiment of a casing morphology determination method provided in the present application;

[0047] Figure 8 It is a characteristic diagram of the overall morphology of the casing according to a simulation result of an embodiment of the casing morphology determination method provided in the present application;

[0048] Fig. 9 It is a schematic diagram of the length of the deformation section of the casing according to the simulation result of an embodiment of the casing shape determination method provided in the present application;

[0049] Fig.10 It is a hardware structure block diagram of an electronic device for a method for determining a sleeve shape provided by the present application;

[0050] Fig.11 It is a schematic diagram of the module structure of an embodiment of the sleeve morphology determination device provided in the present application. DETAILED DESCRIPTION

[0051] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this specification.

[0052] The existing theoretical models of the movement of the two-plate strata during fault slip are mostly based on the overall dislocation of the two-plate strata. However, due to spatial constraints, the impact of the actual fault action on the displacement of the two-plate strata cannot be infinite. The existing theoretical models are obviously inconsistent with the actual geological conditions. Therefore, there is still a lack of clear understanding of the specific displacement distribution of the particles in the two-plate strata during actual fault slip.

[0053] Due to the existence of the fault plane, the actual geological body will produce stress concentration near the fault plane under the action of ground stress. When the shear stress on the fault plane is greater than the cohesion and friction of the fault plane, the two layers of strata around the fault plane will shear and slip along the fault plane at the same time, while the far end of the area not affected by the fault and the stress state remains unchanged, under the spatial constraints of the surrounding rock, the strata do not deform and do not move with the two layers of strata around the fault plane, which leads to the phenomenon that the stratum displacement gradually decays to 0 from the center of the fault to the end along the fault plane, and gradually decays to 0 from the fault plane to both sides in the direction perpendicular to the fault plane. This phenomenon is manifested in space as the two layers of strata around the fault plane are bent, forming the so-called displacement-induced traction structure. With the bending of the strata, the geological body finally reaches a new stress equilibrium state, and the movement of the two layers of strata also stops.

[0054] Based on the above understanding of fault slip movement, it can be known that when fault slip occurs, the existing finite element numerical simulation that only one plate of the fault stratum slips while the other plate of stratum remains stationary, and the moving plate stratum slides as a body with uniform displacement in a direction parallel to the fault surface does not conform to the actual geological conditions. This also leads to the problem that the casing shear deformation morphology obtained by simulation and inversion using finite element numerical simulation software is quite different from the actual casing deformation morphology.

[0055] In view of the problem that the morphology of casing deformation cannot be accurately determined in the existing simulation of casing deformation using finite element numerical simulation software, a casing morphology determination method is provided in an embodiment of the present application. Although the present application provides method operation steps or device structures as shown in the following embodiments or drawings, more or fewer operation steps or module units may be included in the method or device based on routine or no creative labor. In the steps or structures where there is no necessary causal relationship logically, the execution order of these steps or the module structure of the device is not limited to the execution order or module structure described in the embodiments of the present application and shown in the drawings. When the method or module structure is applied to an actual device or terminal product, it can be connected according to the method or module structure shown in the embodiment or drawings for sequential execution or parallel execution (for example, a parallel processor or a multi-threaded processing environment, or even a distributed processing environment).

[0056] Specifically, Figure 1 As shown, the above-mentioned method for determining the sleeve morphology may include the following steps:

[0057] S101: Obtaining a model structure, material parameters, and contact relationships of influencing factors of target casing deformation during horizontal fracturing of a target reservoir, wherein the influencing factors include: fracture upper wall formation, fracture lower wall formation, cement sheath, and target casing.

[0058] Among them, the model structure includes: size, strike and dip of the fault between the upper plate strata and the lower plate strata; material parameters include: Young's modulus, Poisson's ratio and yield strength; contact relationships include: contact relationship between the upper plate strata and the lower plate strata, contact relationship between the upper plate strata and the cement sheath, contact relationship between the lower plate strata and the cement sheath, and contact relationship between the cement sheath and the target casing.

[0059] However, it is worth noting that the model structure, material parameters and contact relationship parameters listed above are only an exemplary description and do not constitute an improper limitation on the present application. In actual implementation, other suitable structures, parameters and relationships can be set according to actual needs, and the present application does not limit this.

[0060] S102: constructing an initial finite element model according to the model structure, material parameters and contact relationship of the influencing factors of the target casing deformation during horizontal fracturing of the target reservoir.

[0061] S103: Meshing the fracture upper wall strata, fracture lower wall strata, cement sheath and target casing in the initial finite element model, and setting the loading mode of the displacement loading boundary of the fracture upper wall strata and the fracture lower wall strata to a displacement attenuation loading mode, so as to form a target finite element model.

[0062] Meshing is one of the necessary steps in finite element modeling and plays a decisive role in the rationality of the model. There are many issues that need to be considered in meshing during the modeling process, such as the number, density, quality, layout, and displacement coordination of the meshes. Specifically, in this application, the meshing of the upper fracture strata, lower fracture strata, cement sheath, and target casing in the initial finite element model is performed through the following steps:

[0063] S1: Setting the grid division mode of the first part of the target casing and the first part of the cement ring to a non-uniform encryption mode, wherein the first part of the target casing is the casing area within a preset range on both sides of the fracture surface of the horizontal fracturing, and the first part of the cement ring is the cement ring area within a preset range on both sides of the fracture surface of the horizontal fracturing.

[0064] S2: Determine the maximum network node spacing and the minimum network node spacing of the non-uniform encryption mode.

[0065] S3: Setting the grid division mode of the upper plate formation of the fracture, the lower plate formation of the fracture, the second part of the target casing and the second part of the cement ring to a uniform division mode, wherein the second part of the target casing is the casing area outside the preset range on both sides of the fracture surface of the horizontal fracturing, and the second part of the cement ring is the cement ring area outside the preset range on both sides of the fracture surface of the horizontal fracturing.

[0066] S4: Determine the grid node spacing of the uniform partitioning mode;

[0067] S5: According to the determined maximum network node spacing and minimum network node spacing of the non-uniform encryption mode and the grid node spacing of the uniform division mode, the fracture upper wall strata, the fracture lower wall strata, the cement sheath and the target casing are gridded.

[0068] Specifically, after completing mesh division of the fault upper wall strata, the fault lower wall strata, the cement sheath and the target casing, the mesh unit type after division can be set to an eight-node hexahedral linear non-conforming mode unit.

[0069] However, it is worth noting that the division mode and grid unit type of the upper plate strata of the fault, the lower plate strata of the fault, the cement ring and the target casing are merely exemplary descriptions and do not constitute improper limitations on the present application. In actual implementation, the grid division mode and grid unit type can be determined according to actual needs, and the present application does not impose any limitations on this.

[0070] In addition, the grid node spacing of the uniform division mode and the maximum network node spacing and minimum network node spacing of the non-uniform encryption mode can also be determined according to actual needs. For example, the grid node spacing of the uniform division mode is set to 100mm, the maximum network node spacing of the non-uniform encryption mode is set to 50mm, and the minimum network node spacing is set to 10mm. This application will not go into details about this.

[0071] Furthermore, the fracture upper plate strata, fracture lower plate strata, cement sheath and target casing are meshed, and the boundary conditions of the finite element model need to be set. In the present application, the boundary conditions of the finite element model are set as the displacement loading boundary of the fracture upper plate strata and the fracture lower plate strata as the displacement loading attenuation mode. Specifically, the displacement attenuation loading mode is that the fracture upper plate strata and the fracture lower plate strata slide in a direction parallel to the fracture surface of the horizontal fracturing, and at corresponding points symmetrical about the center of the fracture surface of the horizontal fracturing, the displacements of the fracture upper plate strata and the fracture lower plate strata are equal in magnitude and opposite in direction, and the displacement loading boundary of the sliding of the fracture upper plate strata and the fracture lower plate strata produces displacement attenuation within the displacement attenuation distance, and the displacement is 0 outside the displacement attenuation distance, wherein the displacement attenuation distance is the horizontal distance between the fracture surface of the horizontal fracturing and the point where the formation displacement attenuates to 0.

[0072] Specifically, the displacement loading boundary of the fracture upper plate strata includes: an upper boundary and a lower boundary of the fracture upper plate strata, and the displacement loading boundary of the fracture lower plate strata includes: an upper boundary and a lower boundary of the fracture lower plate strata.

[0073] Furthermore, the loading mode of the displacement loading boundary of the upper wall strata of the fracture and the lower wall strata of the fracture is changed to the displacement attenuation loading mode, and a displacement attenuation function needs to be set for the displacement loading boundary of the upper wall strata of the fracture and the lower wall strata of the fracture. Specifically, the following steps may be included:

[0074] S1: Establish a local coordinate system with the center point of the fracture surface as the origin as the target coordinate system.

[0075] S2: Determine the attenuation law of the displacement loading boundary of the fault hanging wall strata and the fault footwall strata.

[0076] S3: According to the attenuation law of the displacement loading boundary, a displacement attenuation function of the displacement loading boundary of the upper plate strata of the fracture and the lower plate strata of the fracture is set on the target coordinate system, wherein the displacement attenuation function includes: a linear displacement attenuation function and a quadratic function attenuation function.

[0077] S4: normal constraints are set on the boundaries other than the displacement loading boundaries of the fracture upper wall formation and the fracture lower wall formation, the first end and the second end of the cement sheath, and the first end and the second end of the target casing.

[0078] Specifically, the linear displacement attenuation function is expressed as:

[0079]

[0080] Wherein, D(x, y, z) is the displacement attenuation function, x is the coordinate on the horizontal axis of the target coordinate system, y is the coordinate on the vertical axis of the target coordinate system, z is the coordinate on the vertical axis of the target coordinate system, D0 is the displacement of the displacement loading boundary of the upper wall formation and the lower wall formation of the fault at the fracture surface of the horizontal fracturing, x0 is the displacement attenuation distance, and α is the angle between the fault strike and the well trajectory; is the inclination angle of the fracture, and L, W, and H are the length, width, and height of the entire target finite element model.

[0081] However, it is worth noting that the displacement attenuation function of the displacement loading boundary of the upper plate strata of the fracture and the lower plate strata of the fracture is only an exemplary description and does not constitute an improper limitation on the present application. In actual implementation, the displacement attenuation function that conforms to the attenuation law can be set according to the attenuation law of the displacement loading boundary of the upper plate strata of the fracture and the lower plate strata of the fracture in actual conditions. The present application does not make any limitation on this.

[0082] S104: Execute a simulation task through the target finite element model to obtain a simulation result.

[0083] S105: Determine the deformation state of the target casing according to the simulation result.

[0084] The above method is described below in conjunction with a specific embodiment. However, it should be noted that this specific embodiment is only for better illustrating the present application and does not constitute an improper limitation on the present application.

[0085] In this embodiment, taking into account the problem that the morphology of casing deformation cannot be accurately determined in the existing simulation of casing deformation using finite element numerical simulation software, the knowledge of displacement attenuation during fracture slip is introduced into the simulation. In an embodiment of the present application, a finite element numerical simulation method for casing deformation in a fracture displacement attenuation mode is provided. This method can be used to mesh the model in combination with a uniform division mode and a non-uniform encryption mode, and the boundary conditions of the numerical simulation of casing shear and compression deformation are set to a displacement loading attenuation mode to more accurately determine the morphology of casing deformation, thereby guiding the working direction of casing deformation prevention and control and preventing the activation of through-well fractures during hydraulic fracturing.

[0086] Since the existing finite element model does not take into account the displacement attenuation of the fractured plate, and assumes that only one plate of the fractured plate slips while the other plate is fixed, the moving plate in the model is set to slide as a whole in a uniform displacement manner in a direction parallel to the fracture surface.

[0087] In this embodiment, the loading mode of the finite element model is set to the displacement attenuation mode, such as Figure 2 As shown in the figure, the displacement attenuation mode is to set the two strata of the fault to slide in the direction parallel to the fault surface, and the displacements of the two strata at the corresponding points symmetrical about the center of the fault surface are equal in magnitude and opposite in direction, and the displacement of the same strata gradually decreases in the direction perpendicular to the fault surface, that is, the farther away from the fault surface, the smaller the strata displacement is, until it drops to 0. Furthermore, in the displacement attenuation mode, since the displacement changes of the two strata along the fault surface are naturally generated due to the presence of cement sheath and casing, all displacement loadings are applied to the upper and lower boundaries of the strata in the direction of fault sliding, and no displacement loading is set on the internal and side boundaries of the strata. At the same time, in order to keep the overall model stable during the fault sliding process, normal constraints are set on the remaining outer boundaries of the strata.

[0088] In addition, this embodiment can set different displacement attenuation functions according to different attenuation laws of displacement attenuation, such as linear attenuation and quadratic function attenuation. The displacement attenuation distance can also be set, that is, the horizontal distance between the fault-fracture surface and the formation displacement attenuation to 0. The larger the displacement attenuation distance, the longer the length of the casing deformation simulated by this embodiment will be.

[0089] Specifically, the implementation steps of the finite element numerical simulation method for casing deformation in a fracture displacement attenuation mode provided in this embodiment are as follows:

[0090] S1: Model structure setting.

[0091] In the Abaqus simulation software, the related structures of the two-plate strata, cement sheath and casing are made. According to the simulation requirements, the sizes of the two-plate strata, cement sheath and casing, as well as the direction and dip of the fault are set and the assembly is completed.

[0092] S2: Material parameter setting.

[0093] The material mechanical parameters of the two fractured strata, cement sheath and casing are set according to the actual situation. The material mechanical parameters include Young's modulus, Poisson's ratio and yield strength.

[0094] S3: Contact relationship setting.

[0095] The contact relationship between the various parts of the model is set according to the actual situation, including: the contact relationship between the upper and lower plates of the fracture, the contact relationship between the upper and lower plates of the fracture and the cement sheath, and the contact relationship between the cement sheath and the casing. The default setting of the contact relationship is friction contact, and the friction coefficient is 0.6.

[0096] S4: Loading mode settings.

[0097] Displacement attenuation loading is set at the displacement loading boundaries of the two strata of the fault, and the properties of the fault slip are set according to the actual situation. Specifically, the displacement attenuation loading is that the two strata slip in the direction parallel to the fault surface, and the displacements of the two strata at corresponding points symmetrical about the center of the fault surface are equal in magnitude and opposite in direction.

[0098] Furthermore, setting displacement attenuation loading for all displacement loading boundaries includes: establishing a local coordinate system with the center point of the fracture surface as the origin, setting a displacement attenuation function for the displacement loading boundary, and setting normal constraints on the remaining outer boundaries of the formation and both ends of the cement ring and the casing. By setting displacement attenuation loading for all displacement loading boundaries, displacement attenuation can be achieved for the displacement loading boundaries within the displacement attenuation distance, while the displacement of the displacement loading boundaries outside the displacement attenuation distance is 0.

[0099] S5: Meshing.

[0100] The grid node spacing of the strata, cement sheath and casing on both sides of the fault is set according to the simulation requirements. Generally, the grid node spacing needs to be set according to the size of strata>cement sheath>casing, and the casing and cement sheath grids on both sides of the fault surface need to be non-uniformly encrypted to coordinate the simulation accuracy and calculation amount, and the grid unit type of the strata, cement sheath and casing on both sides of the fault is set to C3D8I.

[0101] S6: Simulation execution.

[0102] Set simulation task parameters according to computer performance and computing speed requirements and execute simulation tasks.

[0103] S7: Analysis of simulation results.

[0104] The degree of consistency between the casing shear-compression deformation morphology in the simulation results and the actual casing deformation morphology is analyzed to obtain simulation insights.

[0105] The finite element numerical simulation method for casing deformation in the fracture displacement attenuation mode is described as follows by taking a specific example. The finite element numerical simulation method for casing deformation may include the following steps:

[0106] S1: Model structure setting.

[0107] Specifically, Figure 3 As shown in the figure, the related structures of the two-wall formations of the fault, cement sheath and casing were made in the Abaqus simulation software. The formation consists of the upper wall and the lower wall of the fault-fracture. The overall size is set to L×W×H=6m×1m×1m. The formation is hollow and filled with cement sheath and casing. The fault-fracture is located between the upper wall and the lower wall formations of the fault-fracture. The angle α between the fault-fracture strike and the well trajectory is set to 90°, and the fault-fracture dip angle is set to 90°. It is set to 60°, the cement ring is located between the formation and the casing, and its wall thickness l1 is set to 38.1mm. The casing is located at the innermost part of the model, and its inner diameter d is set to 118.62mm, and its wall thickness l2 is set to 10.54mm.

[0108] S2: Material parameter setting.

[0109] The Young's modulus and Poisson's ratio of the two strata of the fault are set to be 20 GPa and 0.3 respectively, the Young's modulus and Poisson's ratio of the cement sheath are 10 GPa and 0.25 respectively, and the Young's modulus, Poisson's ratio and yield strength of the casing are 210 GPa, 0.3 and 864 MPa respectively.

[0110] S3: Contact relationship setting.

[0111] The contact relationship between the upper and lower strata of the fault, between the upper and lower strata of the fault and the cement sheath, and between the cement sheath and the casing are all set to friction contact, and the friction coefficient is 0.6.

[0112] S4: Loading mode settings.

[0113] Linear displacement attenuation loading is set at the upper and lower boundaries of the two strata of the fault, and the fault slip properties are set to normal fault properties. Figure 2 As shown in the figure, both strata slide in a direction parallel to the fault surface, and the displacements of the two strata at corresponding points symmetrical about the center of the fault surface are equal in magnitude and opposite in direction. The displacement D0 of the upper and lower boundaries of the two strata at the fault surface is set to 25 mm, the displacement attenuation distance x0 is set to 1 m, and normal constraints are set on the remaining outer boundaries of the strata and both ends of the cement ring and casing.

[0114] Specifically, a local coordinate system with the center point of the fault surface as the origin is established, and a total of four linear displacement attenuation functions are set at the upper and lower boundaries of the two strata of the fault. The expression of the linear displacement attenuation function is:

[0115]

[0116] Where D0 is the displacement of the upper and lower boundaries of the two strata at the fault surface, in m, x is the coordinate on the horizontal axis of the target coordinate system, in m, y is the coordinate on the vertical axis of the target coordinate system, in m, z is the coordinate on the vertical axis of the target coordinate system, in m, x0 is the displacement attenuation distance, in m, α is the angle between the fault-fracture strike and the well trajectory, in °, is the inclination angle of the fault, in degrees, L is the length of the entire model, in meters, W is the width of the entire model, in meters, and H is the height of the entire model, in meters.

[0117] S5: Meshing.

[0118] Specifically, Figure 4 As shown in the figure, the grid node spacing of the upper and lower strata of the fault is set to 100 mm, and it is divided into four parts from the outer boundary to the inner cylinder, so that the grid is gradually tightened from the outside to the inside. Figure 5 As shown in the figure, the axial grid node spacing of the cement sheath is set to 80 mm, and a non-uniform encryption mode is set from 50 mm at the edge to 10 mm at the center on both sides of the fracture surface, with 56 grids set in the annular direction and 4 grids set in the radial direction. Figure 6 As shown, the axial grid node spacing of the casing is set to 50 mm, and a non-uniform encryption mode is set from 20 mm at the edge to 4 mm in the center on both sides of the fracture surface, 76 grids are set in the circumferential direction, and 4 grids are set in the radial direction.

[0119] Furthermore, the grid cell types of the strata, cement sheath and casing on the upper and lower sides of the fault are all set to C3D8I.

[0120] S6: Simulation execution.

[0121] Set simulation task parameters according to computer performance and computing speed requirements and execute simulation tasks.

[0122] S7: Analysis of simulation results.

[0123] Specifically, Figure 7 As shown in the figure, from the local perspective of the contact between the fracture, cement sheath and casing, it can be seen that the casing is subjected to the shearing action of the two layers of strata, resulting in asymmetric compression deformation, strong twisting and shrinkage; Figure 8 As shown in the figure, from the overall perspective of lateral compression, it can be seen that the closer to the fracture surface, the more significant the shear deformation of the casing, the more the casing axis is dislocated, and the casing on both sides gradually returns to its normal shape, and the casing axis returns to its original position. Fig. 9 As shown in the figure, in the model simulation results with a displacement attenuation distance of 1m, the length of the casing deformation section is 2.5m, the inner diameter of the casing is reduced from 118.62mm to 87mm, the casing displacement is approximately 31.6mm, and when the displacement attenuation distance gradually increases, the simulated length of the casing deformation section will also increase accordingly. Therefore, by adjusting the displacement attenuation distance, the actual casing deformation section of several meters or even more than ten meters in length can be simulated and inverted.

[0124] In the above example, the finite element numerical simulation method of casing deformation in the above-mentioned fracture displacement attenuation mode can be used to mesh the model in combination with the uniform division mode and the non-uniform encryption mode, and the boundary conditions of the numerical simulation of casing shear and compression deformation can be set to the displacement loading attenuation mode to more accurately determine the form of casing deformation, thereby guiding the working direction of casing deformation prevention and control and preventing the activation of through-well fractures during hydraulic fracturing.

[0125] The method embodiments provided in the above embodiments of the present application can be executed in a mobile terminal, a computer terminal or a similar computing device. Taking running on an electronic device as an example, Fig.10 is a hardware structure block diagram of an electronic device for a method for determining a sleeve shape provided by the present application. Fig.10 As shown, the electronic device 10 may include one or more (only one is shown in the figure) processors 02 (the processor 02 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA), a memory 04 for storing data, and a transmission module 06 for communication functions. It can be understood by those skilled in the art that Fig.10 The structure shown is only for illustration and does not limit the structure of the above electronic device. Fig.10 More or fewer components as shown, or with Fig.10 Different configurations are shown.

[0126] The memory 04 can be used to store software programs and modules of application software, such as program instructions / modules corresponding to the sleeve morphology determination method in the embodiment of the present application. The processor 02 executes various functional applications and data processing by running the software programs and modules stored in the memory 04, that is, the sleeve morphology determination method of the above-mentioned application is realized. The memory 04 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 04 may further include a memory remotely arranged relative to the processor 02, and these remote memories may be connected to the electronic device 10 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0127] The transmission module 06 is used to receive or send data via a network. The specific example of the above network may include a wireless network provided by a communication provider of the electronic device 10. In one example, the transmission module 06 includes a network adapter (Network Interface Controller, NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission module 06 can be a radio frequency (Radio Frequency, RF) module, which is used to communicate with the Internet wirelessly.

[0128] At the software level, the above-mentioned casing shape determination device can be as follows Fig.11 As shown, including:

[0129] The acquisition module 1101 is used to acquire the model structure, material parameters and contact relationship of the influencing factors of the target casing deformation during the horizontal fracturing of the target reservoir, wherein the influencing factors include: the fracture upper wall formation, the fracture lower wall formation, the cement sheath and the target casing;

[0130] The first forming module 1102 is used to construct an initial finite element model according to the model structure, material parameters and contact relationship of the influencing factors of the target casing deformation during horizontal fracturing of the target reservoir;

[0131] The second forming module 1103 is used to mesh the fracture upper wall formation, the fracture lower wall formation, the cement sheath and the target casing in the initial finite element model, and set the loading mode of the displacement loading boundary of the fracture upper wall formation and the fracture lower wall formation to the displacement attenuation loading mode, so as to form a target finite element model;

[0132] An execution module 1104 is used to execute a simulation task through the target finite element model to obtain a simulation result;

[0133] The determination module 1105 is used to determine the deformation state of the target casing according to the simulation result.

[0134] In one embodiment, the above-mentioned acquisition module 1101 can obtain the model structure, material parameters and contact relationship of the influencing factors of the target casing deformation during horizontal fracturing of the target reservoir, including: the model structure includes: size, the strike and dip of the fracture between the upper plate formation and the lower plate formation; the material parameters include: Young's modulus, Poisson's ratio and yield strength; the contact relationship includes: the contact relationship between the upper plate formation and the lower plate formation, the contact relationship between the upper plate formation and the cement sheath, the contact relationship between the lower plate formation and the cement sheath, and the contact relationship between the cement sheath and the target casing.

[0135] In one embodiment, meshing the fracture upper wall formation, fracture lower wall formation, cement sheath and target casing in the initial finite element model is performed by the second forming module 1103, including:

[0136] Setting the grid division mode of the first part of the target casing and the first part of the cement sheath to a non-uniform encryption mode, wherein the first part of the target casing is the casing area within a preset range on both sides of the fracture surface of the horizontal fracturing, and the first part of the cement sheath is the cement sheath area within a preset range on both sides of the fracture surface of the horizontal fracturing;

[0137] Determine the maximum network node spacing and the minimum network node spacing of the non-uniform encryption mode;

[0138] The grid division mode of the upper wall stratum of the fracture, the lower wall stratum of the fracture, the second part of the target casing and the second part of the cement sheath is set to a uniform division mode, wherein the second part of the target casing is the casing area outside the preset range on both sides of the fracture surface of the horizontal fracturing, and the second part of the cement sheath is the cement sheath area outside the preset range on both sides of the fracture surface of the horizontal fracturing;

[0139] Determine the grid node spacing for uniform partitioning pattern;

[0140] According to the determined maximum and minimum network node spacings of the non-uniform encryption mode and the grid node spacings of the uniform division mode, the fault upper wall strata, the fault lower wall strata, the cement sheath and the target casing are gridded.

[0141] In one embodiment, the second forming module 1103 sets the loading mode of the displacement loading boundary of the fracture upper wall strata and the fracture lower wall strata to the displacement attenuation loading mode, including:

[0142] Establish a local coordinate system with the center point of the fracture surface as the origin as the target coordinate system;

[0143] Determine the attenuation law of the displacement loading boundary of the fault hanging wall strata and the fault footwall strata;

[0144] According to the attenuation law of the displacement loading boundary, a displacement attenuation function of the displacement loading boundary of the upper plate stratum of the fracture and the lower plate stratum of the fracture is set on the target coordinate system, wherein the displacement attenuation function includes: a linear displacement attenuation function and a quadratic function attenuation function;

[0145] Normal constraints are set on the boundaries other than the displacement loading boundaries of the fracture upper wall formation and the fracture lower wall formation, the first end and the second end of the cement ring, and the first end and the second end of the target casing.

[0146] In one embodiment, the displacement attenuation loading mode is that the upper plate strata and the lower plate strata of the fracture slide in a direction parallel to the fracture surface of the horizontal fracturing. At corresponding points symmetrical about the center of the fracture surface of the horizontal fracturing, the displacements of the upper plate strata and the lower plate strata of the fracture are equal in magnitude and opposite in direction, and the displacement loading boundary of the sliding of the upper plate strata and the lower plate strata of the fracture produces displacement attenuation within the displacement attenuation distance, and the displacement is 0 outside the displacement attenuation distance, wherein the displacement attenuation distance is the horizontal distance between the fracture surface of the horizontal fracturing and the point where the formation displacement attenuates to 0.

[0147] In one embodiment, the linear displacement attenuation function is expressed as:

[0148]

[0149] Wherein, D(x, y, z) is the displacement attenuation function, x is the coordinate on the horizontal axis of the target coordinate system, y is the coordinate on the vertical axis of the target coordinate system, z is the coordinate on the vertical axis of the target coordinate system, D0 is the displacement of the displacement loading boundary of the upper wall formation and the lower wall formation of the fault at the fracture surface of the horizontal fracturing, x0 is the displacement attenuation distance, and α is the angle between the fault strike and the well trajectory; is the inclination angle of the fracture, and L, W, and H are the length, width, and height of the entire target finite element model.

[0150] The embodiments of the present application also provide a specific implementation of an electronic device capable of implementing all the steps in the method for determining the cannula morphology in the above embodiments, wherein the electronic device specifically includes the following contents: a processor, a memory, a communications interface, and a bus; wherein the processor, the memory, and the communications interface communicate with each other through the bus; the processor is used to call a computer program in the memory, and when the processor executes the computer program, all the steps in the method for determining the cannula morphology in the above embodiments are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0151] Step 1: Obtain the model structure, material parameters and contact relationship of the influencing factors of the target casing deformation during horizontal fracturing of the target reservoir, wherein the influencing factors include: fracture upper wall formation, fracture lower wall formation, cement sheath and target casing;

[0152] Step 2: construct an initial finite element model according to the model structure, material parameters and contact relationship of the influencing factors of the target casing deformation during horizontal fracturing of the target reservoir;

[0153] Step 3: Meshing the fracture upper wall strata, fracture lower wall strata, cement sheath and target casing in the initial finite element model, and setting the loading mode of the displacement loading boundary of the fracture upper wall strata and the fracture lower wall strata to the displacement attenuation loading mode, so as to form a target finite element model;

[0154] Step 4: Execute the simulation task through the target finite element model to obtain the simulation result;

[0155] Step 5: Determine the deformation state of the target casing according to the simulation results.

[0156] The embodiments of the present application also provide a computer-readable storage medium capable of implementing all the steps in the method for determining the cannula morphology in the above embodiments. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, all the steps in the method for determining the cannula morphology in the above embodiments are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0157] Step 1: Obtain the model structure, material parameters and contact relationship of the influencing factors of the target casing deformation during horizontal fracturing of the target reservoir, wherein the influencing factors include: fracture upper wall formation, fracture lower wall formation, cement sheath and target casing;

[0158] Step 2: construct an initial finite element model according to the model structure, material parameters and contact relationship of the influencing factors of the target casing deformation during horizontal fracturing of the target reservoir;

[0159] Step 3: Meshing the fracture upper wall strata, fracture lower wall strata, cement sheath and target casing in the initial finite element model, and setting the loading mode of the displacement loading boundary of the fracture upper wall strata and the fracture lower wall strata to the displacement attenuation loading mode, so as to form a target finite element model;

[0160] Step 4: Execute the simulation task through the target finite element model to obtain the simulation result;

[0161] Step 5: Determine the deformation state of the target casing according to the simulation results.

[0162] As can be seen from the above description, the embodiment of the present application obtains the model structure, material parameters and contact relationship of the influencing factors of the deformation of the target casing during horizontal fracturing of the target reservoir, wherein the influencing factors include: fracture upper plate formation, fracture lower plate formation, cement ring and target casing; constructs an initial finite element model according to the model structure, material parameters and contact relationship of the influencing factors of the deformation of the target casing during horizontal fracturing of the target reservoir; meshes the fracture upper plate formation, fracture lower plate formation, cement ring and target casing in the initial finite element model, and sets the loading mode of the displacement loading boundary of the fracture upper plate formation and the fracture lower plate formation to the displacement attenuation loading mode to form a target finite element model; performs simulation tasks through the target finite element model to obtain simulation results; determines the deformation state of the target casing according to the simulation results. The above scheme can realize the accurate determination of the shear and compression deformation morphology of the casing, thereby determining the direction of casing deformation prevention and control, and preventing the activation of the through-well fracture during hydraulic fracturing.

[0163] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the hardware + program embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0164] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0165] Although the present application provides method operation steps as described in the embodiments or flowcharts, more or fewer operation steps may be included based on conventional or non-creative labor. The order of steps listed in the embodiments is only one way of executing the order of many steps and does not represent the only execution order. When the actual device or client product is executed, it can be executed in the order of the method shown in the embodiments or the drawings or in parallel (for example, in a parallel processor or multi-threaded processing environment).

[0166] Although the present specification embodiment provides the method operation steps as described in the embodiment or flow chart, more or less operation steps may be included based on conventional or non-creative means. The order of steps listed in the embodiment is only one way in the order of execution of many steps, and does not represent a unique execution order. When the device or terminal product in practice is executed, it can be executed in sequence or in parallel (such as a parallel processor or a multi-threaded processing environment, or even a distributed data processing environment) according to the method shown in the embodiment or the accompanying drawings. The term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, product or equipment including a series of elements not only includes those elements, but also includes other elements not clearly listed, or also includes elements inherent to such process, method, product or equipment. In the absence of more restrictions, it is not excluded that there are other identical or equivalent elements in the process, method, product or equipment including the elements.

[0167] For the convenience of description, the above devices are described in various modules according to their functions. Of course, when implementing the embodiments of this specification, the functions of each module can be implemented in the same or more software and / or hardware, or the module implementing the same function can be implemented by a combination of multiple sub-modules or sub-units. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0168] Those skilled in the art also know that, in addition to implementing the controller in a purely computer-readable program code, the controller can be made to implement the same function in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, such a controller can be considered as a hardware component, and the devices for implementing various functions included therein can also be considered as structures within the hardware component. Or even, the devices for implementing various functions can be considered as both software modules for implementing the method and structures within the hardware component.

[0169] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0170] Those skilled in the art will appreciate that the embodiments of this specification may be provided as methods, systems or computer program products. Therefore, the embodiments of this specification may take the form of complete hardware embodiments, complete software embodiments or embodiments combining software and hardware. Moreover, the embodiments of this specification may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0171] The present specification embodiments may be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The present specification embodiments may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules may be located in local and remote computer storage media, including storage devices.

[0172] Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. In the description of this specification, the description of the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of this specification. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, in the absence of contradiction, a person skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0173] The above is only an example of the embodiment of the present specification and is not intended to limit the embodiment of the present specification. For those skilled in the art, the embodiment of the present specification may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiment of the present specification shall be included in the scope of the claims of the embodiment of the present specification.

Claims

1. A method for determining a sleeve morphology, characterized in that: include: Obtaining the model structure, material parameters and contact relationship of the influencing factors of the target casing deformation during horizontal fracturing of the target reservoir, wherein the influencing factors include: the upper wall formation of the fracture, the lower wall formation of the fracture, the cement sheath and the target casing; An initial finite element model is constructed according to the model structure, material parameters and contact relationship of the influencing factors of the target casing deformation during horizontal fracturing of the target reservoir; Meshing the fracture upper wall strata, the fracture lower wall strata, the cement sheath and the target casing in the initial finite element model, and setting the loading mode of the displacement loading boundary of the fracture upper wall strata and the fracture lower wall strata to a displacement attenuation loading mode, so as to form a target finite element model; Performing a simulation task through the target finite element model to obtain a simulation result; The deformation state of the target casing is determined according to the simulation result.

2. The method according to claim 1, characterized in that The displacement loading boundary of the stratum of the upper plate of the fault includes: the upper boundary and the lower boundary of the stratum of the upper plate of the fault, and the displacement loading boundary of the stratum of the lower plate of the fault includes: the upper boundary and the lower boundary of the stratum of the lower plate of the fault.

3. The method according to claim 1, characterized in that The model structure includes: size, strike and dip of the fault between the upper plate strata and the lower plate strata; material parameters include: Young's modulus, Poisson's ratio and yield strength; contact relationships include: contact relationship between the upper plate strata and the lower plate strata, contact relationship between the upper plate strata and the cement sheath, contact relationship between the lower plate strata and the cement sheath, and contact relationship between the cement sheath and the target casing.

4. The method according to claim 1, characterized in that: Meshing the upper fracture wall formation, the lower fracture wall formation, the cement sheath and the target casing in the initial finite element model includes: Setting the grid division mode of the first part of the target casing and the first part of the cement sheath to a non-uniform encryption mode, wherein the first part of the target casing is the casing area within a preset range on both sides of the fracture surface of the horizontal fracturing, and the first part of the cement sheath is the cement sheath area within a preset range on both sides of the fracture surface of the horizontal fracturing; Determine the maximum network node spacing and the minimum network node spacing of the non-uniform encryption mode; The grid division mode of the upper wall stratum of the fracture, the lower wall stratum of the fracture, the second part of the target casing and the second part of the cement sheath is set to a uniform division mode, wherein the second part of the target casing is the casing area outside the preset range on both sides of the fracture surface of the horizontal fracturing, and the second part of the cement sheath is the cement sheath area outside the preset range on both sides of the fracture surface of the horizontal fracturing; Determine the grid node spacing for uniform partitioning pattern; According to the determined maximum and minimum network node spacings of the non-uniform encryption mode and the grid node spacings of the uniform division mode, the fault upper wall strata, the fault lower wall strata, the cement sheath and the target casing are gridded.

5. The method according to claim 1, characterized in that The displacement attenuation loading mode is that the fracture upper plate strata and the fracture lower plate strata slide in a direction parallel to the fracture surface of the horizontal fracturing, and at corresponding points symmetrical about the center of the fracture surface of the horizontal fracturing, the displacements of the fracture upper plate strata and the fracture lower plate strata are equal in magnitude and opposite in direction, and the displacement loading boundary of the sliding of the fracture upper plate strata and the fracture lower plate strata produces displacement attenuation within the displacement attenuation distance, and the displacement is 0 outside the displacement attenuation distance, wherein the displacement attenuation distance is the horizontal distance between the fracture surface of the horizontal fracturing and the point where the formation displacement attenuates to 0.

6. The method according to claim 1, characterized in that Set the loading mode of the displacement loading boundary of the fault upper wall strata and the fault lower wall strata to the displacement attenuation loading mode, including: Establish a local coordinate system with the center point of the fracture surface as the origin as the target coordinate system; Determine the attenuation law of the displacement loading boundary of the fault hanging wall strata and the fault footwall strata; According to the attenuation law of the displacement loading boundary, a displacement attenuation function of the displacement loading boundary of the upper plate stratum of the fracture and the lower plate stratum of the fracture is set on the target coordinate system, wherein the displacement attenuation function includes: a linear displacement attenuation function and a quadratic function attenuation function; Normal constraints are set on the boundaries other than the displacement loading boundaries of the fracture upper wall formation and the fracture lower wall formation, the first end and the second end of the cement ring, and the first end and the second end of the target casing.

7. The method according to claim 6, characterized in that The linear displacement attenuation function is expressed as: Wherein, D(x, y, z) is the displacement attenuation function, x is the coordinate on the horizontal axis of the target coordinate system, y is the coordinate on the vertical axis of the target coordinate system, z is the coordinate on the vertical axis of the target coordinate system, D0 is the displacement of the displacement loading boundary of the upper wall formation and the lower wall formation of the fault at the fracture surface of the horizontal fracturing, x0 is the displacement attenuation distance, and α is the angle between the fault strike and the well trajectory; is the inclination angle of the fracture, L is the length of the entire target finite element model, W is the width of the entire target finite element model, and H is the height of the entire target finite element model.

8. A device for determining the shape of a casing, characterized in that: include: An acquisition module is used to acquire the model structure, material parameters and contact relationship of the influencing factors of the target casing deformation during horizontal fracturing of the target reservoir, wherein the influencing factors include: fracture upper wall formation, fracture lower wall formation, cement sheath and target casing; The first forming module is used to construct an initial finite element model according to the model structure, material parameters and contact relationship of the influencing factors of the target casing deformation during horizontal fracturing of the target reservoir; The second forming module is used to mesh the fracture upper wall formation, the fracture lower wall formation, the cement sheath and the target casing in the initial finite element model, and set the loading mode of the displacement loading boundary of the fracture upper wall formation and the fracture lower wall formation to the displacement attenuation loading mode to form a target finite element model; An execution module, used to execute the simulation task through the target finite element model to obtain a simulation result; A determination module is used to determine the deformation state of the target casing according to the simulation result.

9. An electronic device, characterized in that: The method comprises a processor and a memory for storing processor-executable instructions, wherein the processor implements the steps of the method according to any one of claims 1 to 7 when executing the instructions.

10. A computer-readable storage medium, characterized in that: Computer instructions are stored thereon, and when the instructions are executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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