HYDROFRACTURING STRESS MEASUR MENT IN DEEP WELL IN CENTRAL HEBEI PLAIN

The principles of hydrofracturing stress measuremen in oil wells in the central Hebei plain have been given. The measurement results of ten oil wells in this region show that three principal stresses linearly increase with depth within 1500m-3200m;their relation is s_h >S_V >Sh. In addition according to the results of hydrofracturing stress measurement in Yixian county of Hebei province and focal mechanism, the direction of major horizontal principal stress is NE-NEE. it is shown that recent crustal movement in the central Hebei plain is mainly horizontal, and the active properties of the four groups of faults in the region are as following, NE and EW faults are tensile, NNE are right-lateral strike slip and NE are left-lateral strike slip.