Borehole wall stability analysis method and device for stratum, medium and equipment

Abstract

The invention relates to a borehole wall stability analysis method and device for a stratum, a medium and equipment. The borehole wall stability analysis method comprises the steps that (1) all-directional pressure parameters of the stratum are collected; (2) a core sample of a target stratum is acquired, and a stress-strain constitutive relation is determined through an experiment; (3) an initial crustal stress state and geomechanical characteristics of the stratum are described based on the stress-strain constitutive relation; (4) a three-dimensional non-structural geometric grid is established, and space geometric parameters of a borehole wall stable model are determined; (5) an initial three-dimensional geomechanical model is formed; (6) a theoretical model is established based on each directional parameter of the stratum; (7) on the basis of representing spatial-temporal evolution characteristics of a single physical field, borehole wall stability analysis under multi-physical field coupling and cooperation is achieved; (8) spatial discretization is performed on a multi-physics field coupling partial differential equation set by using a finite element method; (9) the borehole wall instability possibility is quantitatively analyzed; and (10) well drilling parameter optimization on an oil field site is helped.

Description

technical field [0001] The present invention relates to a wellbore stability analysis method, device, medium and equipment for strata, in particular to a fluid-solid-thermal multi-field coupling wellbore stability analysis method, device, The medium and equipment belong to the technical field of borehole wall stabilization in deep and ultra-deep formations. Background technique [0002] The safe and efficient drilling and production of deep and ultra-deep oil and gas reservoirs is an important way to alleviate my country's high dependence on foreign crude oil and natural gas. However, this type of reservoir has the characteristics of high temperature, high stress, and high formation pressure at the same time. Compared with shallow reservoirs, the coupling effect of various physical fields is more obvious, and the degradation mechanism of rock mechanical properties around the well and the law of stress response are more obvious. In the development process, low drilling effic...

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Problems solved by technology

However, for deep and ultra-deep formations, due to the high temperature of the geothermal gradient, the influence of thermal-solid coupling and fluid-thermal coupling on the stress field and pressure field will cause thermal strain and heat transfer, and at the same time cause rock elasticity. Therefore, there are limitations in the accuracy and adaptability of common fluid-solid coupling wellbore stability methods in such scenarios

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