Method and system for simulating deformation of natural fracture sliding shear shale gas horizontal well casing under multi-stage fracturing

Abstract

The invention discloses a method and a system for simulating deformation of a natural fracture slippage shear shale gas horizontal well casing under multistage fracturing. The method comprises the following steps: establishing a natural fracture slippage shear casing model; performing finite element mesh generation on the natural fracture slippage shear casing model, and substituting a fracture angle, a stratum elastic modulus, a casing elastic modulus or a casing wall thickness to obtain a casing Mises stress curve graph; and substituting the crack angle and the slip distance to obtain an inner diameter curve graph of the casing deformation failure about the crack angle and the slip distance. Aiming at the problem of failure of the shale gas horizontal well casing due to different fracture angles and different formation properties, by means of finite element software, shear deformation of the shale gas horizontal well casing is studied through finite element analysis, and the slip limit of a shear casing variable-jamming bridge plug caused by fracture slip at different angles is analyzed; and a data support is provided for avoiding natural cracks as much as possible during well drilling, ensuring normal hydraulic fracturing work and reducing the failure probability of the horizontal well.

Description

Technical field [0001] The present invention relates to the field of shale gas exploration and mining technology, and more particularly to a multi-stage fracturing of natural crack slip shear deformation simulation method and system. Background technique [0002] In the work of shale gas exploration and mining, in order to increase the yield of the shale gas well, the horizontal well is needed to make multi-stage fractise, but this process may cause the sleeve to be deformable, resulting in a reduction of the shale gas well or aborted. Damaged casing did not appear in tube wall damage, drilling fluid leakage, according to multi-arm well diameter logging, the damage mode is mainly the shearing deformation, and the damage position is mostly natural crack development. Taking the well group located in Weiyuan, the Sichuan Province, according to the site data, the number of sleeves in the 90-port level is found to be 54, the single well sleeve deformation point is 1 ~ 3, mostly shear ...

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Problems solved by technology

[0007] The main purpose of the present invention is to provide a method and system for simulating the casing deformation of natural fractures under multi-stage fracturing by slipping and shearing shale gas horizontal wells, aiming to solve the problem in the prior art in the process of shale gas exploration and production. The reasons for the casing's own load and deformation encountered have not been analyzed and studied.

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