The research on the in-situ stress of Dabei12 gas reservoir in Kelasu structural belt of Kuqa Depression was carried out to clarify the distribution of in-situ stress in deep reservoirs and explore the heterogeneous distribution mechanism of the in-situ stress. In addition，suggestions were put forward for well placement against a complex geological background.The results demonstrate that the reservoir at more than 4 500 m in Kelasu structural belt follows a strike-slip in-situ stress mechanism. The maximum horizontal principal stress in Dabei12 gas reservoir ranges from 125 to 160 MPa，and the minimum horizontal principal stress is 118-130 MPa. The in-situ stress shows strong heterogeneity and the difference between wells is evident. Complex geological boundary conditions and interbedded lithology of the reservoir lead to the extremely heterogeneous in-situ stress distribution. Favorable and unfavorable areas of in-situ stress are alternately distributed，and the unfavorable area may also be drilled in the structural high. Therefore，the plan of“occupying the high point along the long axis”cannot be simply implemented for well placement. Moreover，a directional well crosses a wide favorable area，with a high probability of penetration of fractures as well as a safe and stable well trajectory，and it can avoid obstacles and risks. Accordingly，it is a preferable well type against a complex geological background. It is suggested that the well trajectory should be designed in the direction with low stress，well-developed fracture，and high borehole wall stability，and a reasonable reservoir simulation mode should be selected according to in-situ stress.
XU Ke, ZHANG Hui, LIU Xinyu, WANG Zhimin, LAI Shujun. Current in-situ stress characteristics of deep fractured reservoirs in Kuqa Depression and its guiding significance to natural gas exploration and development[J]. Petroleum Geology and Recovery Efficiency,2022,29(2):34~45Copy