The Application of Hydraulic Fracturing Stress Measurement in Hydroelectric Projects of China

Compared to the other methods of stress measurement, classical hydraulic fracturing(HF) technique is a relatively convenient and economic method to determine stress and interpret the test results. However the HF method can only obtain the local dimensional (2D) stress of the plane perpendicular to the axis of test holes. In this paper, two HF measurement campaigns applied in two hydroelectric projects in China have been presented to describe how to obtain the three dimensional (3D) stress from three different direction shallow boreholes in the same section by HF, and how to carry out the back analysis of a large scale area stress field based on the test results.