A new method of three dimensional in situ stress measurements by hydraulic fracturing technique

摘要

This paper presents a new method for three dimensional in situ stress measurements by hydraulic fracturing technique. By this method, tests are carried out in at least three boreholes of different orientation. For each borehole, hydraulic fracturing test was carried out just as the traditional procedure and the breakdown pressure (P_b), shut in pressure (P_s) as well as the occurrence of the induced fracture were obtained. By use of these observed values, according to the theory of this new method, the in situ stress tensor can be determined. In this paper, the theoretical model of this method was introduced at first, and relevant equations were deduced and presented here. To illustrate the method and confirm its adaptability to practical use, a calculation example was presented here and further study regarding to the influence of observed value error on inversed stress results was carried out.