水压致裂法三维地应力测量的理论探讨

THEORETICAL DISCUSSION ON 3 D HYDRAULIC FRACTURING IN SITU STRESS MEASUREMTNT

本文对现有的水压致裂三维地应力测量方法进行了深入的力学分析，在此基础上提出了新的理论模型。新的理论模型采用了最小主应力破坏准则，与现有方法采用的最小切向应力破坏准则相比，更客观的表述了水压致裂过程中的力学机制。为说明该方法的工作步骤及其可行性，文中利用遗传算法反演技术，对假设的地应力状态进行了试算。试算结果表明该方法是可行的。

In this paper,the mechanics analysis for the traditional 3 D hydraulic fracturing in situ stress measurment method is done,and a new theoretical model proposed.The minimum principal stress criteria adopted in the new model,compared with the minimum tangential stress criteria of traditional method,illustrates the mechanism during hydraulic fracturing procedure more objectively.To illustrate the procedure of this method and its applicability,the genetic algorithms inversion technique is adopted to estimate assumed stress state.The results show that the method is applicable.