| China has abundant shale gas resources and great potential for exploitation.However,shale gas development in China is still at a preliminary stage and faces many technical difficulties.Among them,the distribution law of ground stress field is the basic data of the shale gas exploration and development program design and the optimal design of hydraulic fracturing.Due to the discreteness of measured data points in field stress,high engineering costs,and long test time,it is necessary to perform numerical simulations of the regional stress field in order to better serve fracturing design optimization.This article mainly completed the following work:This thesis mainly investigates existing methods and methods of in-situ stress measurement,including hydraulic fracturing,acoustic emission Kaiser effect,borehole avalanche ellipticity,wave velocity anisotropy and acoustic emission combination method,ground breaking experiment and differential strain combining method,stress function method,displacement function method,multiple linear regression method and neural network method.On this basis,an indoor experiment of shale rock mechanics parameters was carried out.The rock mechanics parameters of the study area were obtained through rock triaxial strength experiments,thus providing basic data for subsequent numerical simulation.At the same time,the shale mineral composition and content were analyzed by XRD diffraction.Based on the above studies,a simulation and calculation of the in-situ stress field was performed for the square area of 12 km in the middle of the YS108 block of the Huangjinba in Zhaotong,Yunnan.Based on the multiple linear regression method,the ABAQUS finite element software was used to simulate the ground stress field.Finally,the numerical simulation of the ground stress and the measured ground stress were compared and analyzed.The shale reservoir in-situ stress field numerical model established in this paper can provide reference for on-site ground stress analysis. |
PDF Full Text Request