主方向差应变地应力测量方法

Principal Direction Differential Strain Method for In-Situ Stress Measurement and Application

常规差应变法测量地应力的实验难度较大。针对这一难题,在常规差应变分析法的基础上,首次将岩石波速各向异性特征与地应力方向相关原理引入到差应变分析实验中,提出了一套简易可行的室内地应力测量新方法——主方向差应变分析法。该方法利用岩心波速各向异性特性确定水平主应力的方向,按照该方向来制备差应变实验岩样并进行实验。将该方法的测量结果与目前广泛使用的精度较高的水压致裂法的测量结果进行比较,二者吻合较好。实践证明:主方向差应变分析法测量精度较高,并较之常规差应变分析法降低了实验难度及工作量。

Big difficulty normally appears in lab terrestrial stress measurement by conventional differential strain method. This paper firstly introduces the theory about anisotropy of core wave velocity vs. in-situ stress direction into differential strain analysis （DSA）, and proposes a new simple and practicable method for lab in-situ stress measurement-principal direction differential strain analysis （PDDSA）. The principle of this method is using anisotropy of core wave velocity to measure horizontal principal stress by which prepares samples for DSA experiment. The results by PDDSA are consistent with relatively high-accuracy hydraulic fracturing measures, indicating tha! PDDSA is better than DSA in accuracy, lab experimental difficulty and work requirement.