水压致裂法地应力测量的数值模拟

由于测量深度深及其他突出优点,水压致裂法在地应力测量中已在国内外得到了广泛使用。基于大型通用有限元软件平台 Abaqus,建立了二维应力-损伤演化模型,对不同水压及初始裂隙下的多工况进行数值模拟试验,并与理论解进行比较以验证数值模拟结果的可靠性。分析结果表明:数值模拟试验的裂纹开展方位、致裂压力最小值与理论解吻合;初始裂隙的存在将影响致裂最小水压力值和裂纹扩展方向及模式,其结果可对原位地应力测试和水压致裂工程设计提供借鉴和指导。

Numerical Simulation of Hydraulic Fracturing Technique in Geostress Measurement

Hydraulic fracturing as a technique of geostress measurement has been widely used both at home and abroad due to its many outstanding merits.Based on the universal finite element software Abaqus,a 2D stress-damage planar model with different hydraulic and native fissure has been created,its reliability is verified by comparing the numerical simulation results with theoretical solutions.The analysis results show that the crack orientation and the minimum pressure are in accordance with theoretical results.The rock’s fissures will affect the minimum fracturing pressure,the crack direction and its extension mode.This study is a valuable guide to geostress measurement and hydraulic fracturing design.