Oil and gas well casing deformation and damage early warning method based on CT scanning

Abstract

This invention discloses a CT scan-based early warning method for casing deformation and damage in oil and gas wells, comprising the following steps: establishing a full-diameter heterogeneous three-dimensional micro / nano core model; constructing a full-diameter finite element solid mechanics structure three-dimensional digital model of the core including the wellbore; constructing a core fluid mechanics three-dimensional digital model including the wellbore; establishing a solid-liquid coupled multi-element three-dimensional digital finite element mechanical structure model of the core finite element solid mechanics structure and the core fluid mechanics three-dimensional digital model; establishing a casing deformation and damage mechanism model under different stress conditions; establishing an artificial intelligence early warning method for casing deformation and damage in oil and gas wells, predicting the occurrence mechanism of casing deformation and damage in oil and gas wells, obtaining the status of casing deformation and damage at each stage of oil and gas well development, predicting the occurrence period of casing deformation and damage during oil and gas well development, and providing early warning information. This improves the technical implementation level and efficiency of oil and gas deep development, and reduces oil and gas development costs.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas well exploration and management technology, and relates to a method for early warning of casing deformation and damage in oil and gas wells based on CT scanning. Background Technology

[0002] Monitoring and predicting casing deformation and damage in oil and gas wells has long been a world-class technical challenge in oil and gas development engineering, requiring a long-term solution but remaining unresolved. Current imaging logging and microseismic technologies can only provide monitoring; they cannot predict the mechanisms, timing, and evolution of casing deformation and damage during oil and gas well production. This makes it impossible to effectively prevent casing deformation and damage, resulting in a lack of technical support for subsequent production and performance evaluation. With the advent of CT non-destructive testing technology, combined with artificial intelligence simulation technology, a new technical guarantee has been provided for predicting casing deformation and damage during oil and gas well production. As oil and gas exploration and development deepen, the areas available for exploration are decreasing, and new discoveries are becoming increasingly difficult. Therefore, the deep development of remaining oil and gas is gradually becoming a key area of ​​focus for current and future oil and gas development. The longer the production cycle of an oil and gas well, the greater the probability of casing deformation and damage. Preventing casing deformation and damage is the cornerstone of remaining oil and gas development and its effectiveness and benefits, and is one of the core contents of oil and gas well development management.

[0003] Therefore, there is an urgent need to develop a new method for early warning of casing deformation and damage in oil and gas wells based on full-diameter core CT scanning. This method would provide the optimal solution for preventing casing deformation and damage during oil and gas well production, accurately predict the timing and stratigraphic sequence of casing deformation and damage during oil and gas well production, and provide technical information for oil and gas development design. This would not only help control the optimal state of the casing in oil and gas production wells, but also better guide the efficient and in-depth development of oil and gas, improve the benefits of refined development, reduce risks, and provide services for geological exploration using next-generation high technology. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the aforementioned background technology and provide a CT scan-based early warning method for preventing casing deformation and damage in oil and gas wells. This method offers the optimal solution for preventing casing deformation and damage during oil and gas well production, enabling accurate evaluation and prediction of the timing and formation of casing deformation and damage during oil and gas well production. It also allows for advance forecasting of formations and timing prone to casing deformation and damage, thereby improving the technical implementation level and efficiency of deep oil and gas development and reducing oil and gas development costs.

[0005] The technical solution adopted in this invention is a method for early warning of casing damage in oil and gas wells based on CT scanning, comprising the following steps:

[0006] S110: Based on the oil and gas geological background, the full-diameter core CT scanning technology is used to obtain grayscale data volume of core composition, pores, fractures and internal structural heterogeneity, and to establish a three-dimensional micro-nano core model of full-diameter core heterogeneity.

[0007] S120: Using a full-diameter heterogeneous three-dimensional micro-nano core model, based on drilling engineering design parameters, a full-diameter core finite element solid mechanical structure three-dimensional digital model including the wellbore is constructed.

[0008] S130: Using the three-dimensional digital model of the solid mechanical structure of the core finite element, construct a three-dimensional digital model of the core fluid dynamics including the wellbore, and establish a solid-liquid coupled multi-element three-dimensional digital finite element mechanical structure model of the core finite element solid mechanical structure and the three-dimensional digital model of the core fluid dynamics.

[0009] S140: Using the finite element method, simulate and predict the deformation, rupture, and faulting of oil and gas well casing under different pressures, as well as the mechanisms, development and evolution laws and differences, and establish casing deformation and damage mechanism models under different stress conditions;

[0010] S150: Using artificial intelligence methods, an AI-based early warning method for casing deformation and damage in oil and gas wells is established based on a casing deformation and damage mechanism model under different stress conditions. This method predicts the occurrence mechanism of casing deformation and damage in oil and gas wells, obtains the status of casing deformation and damage at each stage of oil and gas well development, and then predicts the timing of casing deformation and damage during the development of oil and gas wells, providing early warning information.

[0011] Furthermore, the core sampling criteria in S110 are as follows: the type and model of the pressure-maintaining and shape-preserving sleeve selected based on the core type must not change the original state of the core during the core sampling process.

[0012] Furthermore, in S110, the standard for selecting the X-ray source current and voltage during CT scanning is: the selection of the current and voltage level must meet the requirement that the generated X-rays can effectively penetrate the sleeve and core to obtain rock fractures and their spatial structural heterogeneity.

[0013] Furthermore, in S120, the construction standard for the three-dimensional digital model of the finite element solid mechanics structure of the core includes: based on the established three-dimensional micro-nano core model of the full-diameter heterogeneous core, constructing a three-dimensional coupled model of core composition, pores, and fractures to ensure that the finite element mechanical structure model of the core can reflect the true structural state of the core of the target underground layer.

[0014] Furthermore, the construction standard for the three-dimensional digital model of the core finite element solid mechanics structure also includes: based on the established full-diameter heterogeneous three-dimensional micro-nano core model, a wellbore of a certain proportion is constructed in it to ensure that the three-dimensional digital model of the core finite element solid mechanics structure containing the wellbore can reflect the true structural state of the underground target layer.

[0015] Furthermore, the construction standard for the casing of the wellbore in the three-dimensional digital model of the core finite element solid mechanics structure in S120 is as follows: it is constructed proportionally according to the casing material, thickness, and well diameter in the drilling engineering design scheme.

[0016] Furthermore, S120 also includes constructing a multi-element coupled three-dimensional digital core finite element mechanical structure model of the wellbore based on the single core finite element solid mechanical structure three-dimensional digital digital model.

[0017] Furthermore, the construction standard for the core fluid dynamics three-dimensional digital model containing the wellbore in S130 is: to construct it in stages according to the key stages of the change in the fluid properties of the wellbore.

[0018] Furthermore, the different pressure effects in S140 include external force effects, production pressure differential effects, and combined effects of external force and production pressure differential effects.

[0019] The beneficial effects of this invention are:

[0020] 1) It fills the gap in quantitative evaluation methods for early warning of casing deformation and damage in oil and gas wells. By using a quantitative model of the spatial variation of rock strata grayscale collected by CT scans, and applying finite element mechanical simulation methods and artificial intelligence discrimination technology, it accurately evaluates the timing and stratigraphic segments in which casing deformation and damage occur during the production process of oil and gas wells, and predicts in advance the stratigraphic segments and timing that are prone to casing deformation and damage, providing more effective technical information for the maintenance and management of oil and gas development and production wells.

[0021] 2) Improve the efficiency of oil and gas development and reduce costs. This invention utilizes CT non-destructive testing technology, applies finite element mechanical simulation methods and artificial intelligence discrimination methods to establish a prediction and evaluation method and technical standard for the occurrence of casing deformation and casing damage in oil and gas well production processes that conforms to the geological conditions of the region. It uses artificial intelligence simulation to accurately evaluate the artificial fracturing fracture network and differences in each segment of the cored layer, and optimizes the maintenance and treatment scheme for oil and gas development production wells, thereby improving the effectiveness of production well maintenance and treatment, increasing oil and gas development efficiency, and reducing oil and gas development costs. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a flowchart of a method for early warning of casing deformation and damage in oil and gas wells based on CT scanning, according to an embodiment of the present invention.

[0024] Figure 2 This is a ternary coupled model diagram of core composition, pores, and fractures according to an embodiment of the present invention.

[0025] Figure 3 This is a solid-liquid coupling model diagram according to an embodiment of the present invention.

[0026] Figure 4 This is a finite element structural diagram of a core sample, including a simulated wellbore before deformation, established based on CT scans according to an embodiment of the present invention.

[0027] Figure 5 This is a finite element structural diagram of a simulated wellbore after stage deformation, based on a CT scan and established from a core sample according to an embodiment of the present invention.

[0028] Figure 6 This is a finite element structural diagram of a simulated wellbore with complete casing deformation, based on a CT scan core, according to an embodiment of the present invention. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] like Figure 1 As shown, this invention provides a method for early warning of casing damage in oil and gas wells based on CT scanning, comprising the following steps:

[0031] S110: Based on the petroleum geological background, full-diameter core CT scanning technology was used to scan and acquire grayscale images of core composition, pores, fractures, and internal structural heterogeneity. A three-dimensional image model of the full-diameter heterogeneous micro / nano core was established using reconstruction techniques. Based on the three-dimensional images, digital core image processing and interpretation technology was applied to extract three-dimensional graphics and data such as rock mineral content, pores, fractures, and laminae.

[0032] In some implementations, the core sampling criteria are as follows: the type and model of the pressure-holding and conformal sleeve selected based on the core type must ensure that the original state of the core is not altered during the core sampling process.

[0033] In some implementations, the criteria for selecting the X-ray source current and voltage during CT scanning are: the selection of the current and voltage level must ensure that the generated X-rays can effectively penetrate the sleeve and core, and obtain good information about rock fractures and their spatial structural heterogeneity.

[0034] S120: Using a full-diameter heterogeneous three-dimensional micro-nano core model, based on drilling engineering design parameters, a full-diameter finite element solid mechanical structure three-dimensional digital model of the core including the wellbore is constructed.

[0035] In some implementations, the criteria for constructing a three-dimensional digital model of a core solid mechanics structure using the finite element method include: based on the established three-dimensional micro / nano core model of a full-diameter heterogeneous core, constructing, for example... Figure 2 The core composition (rock mineral content), pores, and fractures shown in the three-element coupled model (i.e., a three-dimensional digital model of the core finite element solid mechanical structure including the wellbore) ensures that the core finite element mechanical structure model can well reflect the real structural state of the target underground core.

[0036] In some implementations, the construction criteria for the three-dimensional digital model of the core finite element solid mechanics structure also include: based on the established full-diameter heterogeneous three-dimensional micro-nano core model, constructing a wellbore of a certain proportion within it to ensure that the three-dimensional digital model of the core finite element solid mechanics structure containing the wellbore can well reflect the true structural state of the underground target layer.

[0037] In some implementations, the construction standard for the well casing in the three-dimensional digital model of the core finite element solid mechanics structure is: to construct it proportionally according to the casing material, thickness, well diameter, etc. in the drilling engineering design scheme.

[0038] In some implementations, a multi-element coupled three-dimensional digital core finite element mechanical structure model of the wellbore is further constructed based on the single core finite element solid mechanical structure three-dimensional digital digital core finite element mechanical structure model.

[0039] S130: Utilizing a 3D digital model of the core solid mechanics structure using the finite element method (FEM) method, a 3D digital model of the core fluid mechanics structure, including the well casing, is constructed. This establishes a solid-liquid coupled multi-element 3D digital finite element mechanical structure model combining the core solid mechanics structure and the core fluid mechanics structure. Specifically, the fluid solver in the well casing and the rock solid structure (pores, fractures, minerals) solver are used to calculate the interaction between the fluid and rock solids in the casing, achieving solid-liquid coupled calculation. The fluid solver in the casing is mainly responsible for calculating physical quantities such as pressure, velocity, temperature, and composition of the flow field, while the rock structure solver is responsible for calculating displacement, stress, and strain. Among these solution variables, pressure and displacement are the physical quantities simultaneously present in the fluid and rock solid solutions within the casing, enabling coupled calculation simulation of the fluid and rock matrix within the casing, yielding results such as... Figure 3 The solid-liquid coupling model shown.

[0040] Specifically, based on the actual pore and fracture fluid properties of the rock core, a solid-liquid coupled binary three-dimensional digital rock core finite element mechanical structural model is established, which combines the three-dimensional solid structure model of the rock core with the three-dimensional fluid structure model of the pores and fractures.

[0041] Furthermore, the standard for constructing a three-dimensional digital model of core fluid dynamics, including the wellbore, is to construct it in stages based on the key stages of changes in the fluid properties of the wellbore.

[0042] S140: Using the finite element method, simulate and predict the deformation, rupture, and faulting of oil and gas well casing under different pressures, as well as the mechanisms, development and evolution laws and differences, and establish casing deformation and damage mechanism models under different stress conditions.

[0043] In some implementations, external forces are one of the main factors causing casing deformation and damage in oil and gas wells, which are caused by tectonic movements or artificial construction, simulating the casing deformation process caused by stress changes due to external forces.

[0044] In some implementations, the production pressure difference is also one of the main factors of casing deformation and damage in oil and gas wells. During the production process, the heterogeneity of the reservoir leads to differences in the degree of oil and gas fluid production in different layers, resulting in pressure differences between adjacent reservoir fluids. Under the action of this pressure difference, casing deformation and damage occur, simulating the casing change process caused by changes in production pressure difference.

[0045] In some implementations, the combined effect of external forces and production pressure differentials can lead to more severe casing deformation and damage in oil and gas wells, simulating the casing change process caused by the combined effect of external forces and production pressure differentials.

[0046] S150: Applying artificial intelligence methods, an AI-based early warning method for casing deformation and damage in oil and gas wells is established based on a casing deformation and damage mechanism model under different stress conditions. This method predicts the casing deformation and damage mechanism in oil and gas wells, evaluates the casing deformation and damage status at each stage of oil and gas well development, and provides early warning technical information for predicting the occurrence period and remediation plan of casing deformation and damage during oil and gas well development.

[0047] In some implementations, the artificial intelligence method can be natural language processing, inference systems, or other artificial intelligence methods.

[0048] In some implementations, an established casing deformation and casing damage mechanism model is used to calculate, simulate, and deduce the occurrence process and evolution law of casing deformation and casing damage under different stress conditions in oil and gas wells, the main controlling factors and deformation modes of casing deformation and casing damage in oil and gas wells, and the degree of impact on production.

[0049] In some implementations, an artificial intelligence early warning method for casing deformation and damage in oil and gas wells is established based on a casing deformation and damage mechanism model under different stress conditions. This method predicts the casing deformation and damage mechanism in oil and gas wells, evaluates the casing deformation and damage status at each stage of oil and gas well development, predicts the timing of casing deformation and damage during oil and gas well development, and provides early warning technical information.

[0050] like Figures 4-6 As shown in the figure, the method for early warning of casing deformation and damage in oil and gas wells based on CT scanning of the present invention is used to simulate the various stages of casing deformation evolution in actual production work, which proves the feasibility of the method of the present invention.

[0051] This invention provides a CT-based method for early warning of casing deformation and damage in oil and gas wells. It utilizes CT non-destructive testing technology to establish a full-diameter core heterogeneous three-dimensional micro / nano rock layer model. Through finite element mechanical simulation and artificial intelligence simulation and recognition methods and standards, it provides the optimal solution for preventing casing deformation and damage during oil and gas well production. This allows for accurate evaluation and prediction of the timing and layers where casing deformation and damage occur during oil and gas well production, and early forecasting of layers and periods prone to casing deformation and damage. This improves the technical level of preventing and predicting casing deformation and damage in oil and gas development, enhances the efficiency of oil and gas development, and reduces oil and gas development costs.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A method for early warning of casing damage in oil and gas wells based on CT scanning, characterized in that, Includes the following steps: S110: Based on the oil and gas geological background, the full-diameter core CT scanning technology is used to obtain grayscale data volume of core composition, pores, fractures and internal structural heterogeneity, and to establish a three-dimensional micro-nano core model of full-diameter core heterogeneity. S120: Using a full-diameter heterogeneous three-dimensional micro-nano core model, based on drilling engineering design parameters, a full-diameter core finite element solid mechanical structure three-dimensional digital model including the wellbore is constructed. S130: Using the 3D digital model of the solid mechanical structure of the core finite element method, a 3D digital model of the fluid dynamics of the core containing the well casing is constructed. A solid-liquid coupled multi-element 3D digital finite element mechanical structure model is established by combining the 3D digital model of the solid mechanical structure of the core finite element method with the 3D digital model of the fluid dynamics of the core. Specifically, the fluid solver and the rock solid structure solver in the well casing are used to calculate the interaction between the fluid and the rock solid in the casing, realizing solid-liquid coupled calculation. The fluid solver in the casing is responsible for calculating the physical quantities of pressure, velocity, temperature, and composition of the flow field, while the rock structure solver is responsible for calculating displacement, stress, and strain. S140: Using the finite element method, simulate and predict the deformation, rupture, and faulting of oil and gas well casing under different pressures, as well as the mechanisms, development and evolution laws and differences, and establish casing deformation and damage mechanism models under different stress conditions; S150: Using artificial intelligence methods, an AI-based early warning method for casing deformation and damage in oil and gas wells is established based on a casing deformation and damage mechanism model under different stress conditions. This method predicts the occurrence mechanism of casing deformation and damage in oil and gas wells, obtains the status of casing deformation and damage at each stage of oil and gas well development, and then predicts the timing of casing deformation and damage during the development of oil and gas wells, providing early warning information.

2. The method for early warning of casing damage in oil and gas wells based on CT scanning according to claim 1, characterized in that, The core sampling standard in S110 is that the type and model of the pressure-maintaining and shape-preserving sleeve selected based on the core type must not change the original state of the core during the core sampling process.

3. The method for early warning of casing damage in oil and gas wells based on CT scanning according to claim 1, characterized in that, In S110, the standard for selecting the X-ray source current and voltage during CT scanning is: the selection of the current and voltage level must meet the requirement that the generated X-rays can effectively penetrate the sleeve and core to obtain rock fractures and their spatial structural heterogeneity.

4. The method for early warning of casing damage in oil and gas wells based on CT scanning according to claim 1, characterized in that, In S120, the construction standard of the three-dimensional digital model of the finite element solid mechanics structure of the core includes: based on the established three-dimensional micro-nano core model of the full-diameter heterogeneous core, constructing a three-dimensional coupled model of core composition, pores, and fractures to ensure that the core finite element mechanical structure model can reflect the real structural state of the core of the target underground layer.

5. A method for early warning of casing damage in oil and gas wells based on CT scanning, as described in claim 1 or 4, characterized in that, The construction criteria for the three-dimensional digital model of the core finite element solid mechanics structure also include: based on the established full-diameter heterogeneous three-dimensional micro-nano core model, a wellbore of a certain proportion is constructed in it to ensure that the three-dimensional digital model of the core finite element solid mechanics structure containing the wellbore can reflect the true structural state of the underground target layer.

6. The method for early warning of casing deformation and damage in oil and gas wells based on CT scanning according to claim 1, characterized in that, The construction standard for the casing of the wellbore in the three-dimensional digital model of the finite element solid mechanics structure of the core in S120 is as follows: it is constructed proportionally according to the casing material, thickness, and well diameter in the drilling engineering design scheme.

7. The method for early warning of casing damage in oil and gas wells based on CT scanning according to claim 1, characterized in that, S120 further includes constructing a multi-element coupled three-dimensional digital core finite element mechanical structure model of the wellbore based on the single core finite element solid mechanical structure three-dimensional digital digital model.

8. The method for early warning of casing damage in oil and gas wells based on CT scanning according to claim 1, characterized in that, The construction standard for the core fluid dynamics three-dimensional digital model containing the wellbore in S130 is: to construct it in stages according to the key stages of the change in fluid properties in the wellbore.

9. The method for early warning of casing deformation and damage in oil and gas wells based on CT scanning according to claim 1, characterized in that, The different pressure effects in S140 include external force effects, production pressure differential effects, and combined effects of external force and production pressure differential effects.

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