Abstract:By testing TP131H well, it is known that the target layer is water layer. The five-section sidetracking horizontal well TP131HCH was designed based on the analysis on seismic data in order to improve the producing degree of reserves around the well and reduce drilling cost by making full use of the old well in vertical well section. Due to the steady inclined section, the horizontal displacement of wellbore trajectory is effectively extended by five-section horizontal well, which meets the requirements of geological water avoidance. According to the difficulties caused by ultra depth and high temperature of openhole sidetracking horizontal well TP131HCH, the paper introduces the relevant methods such as optimization design of borehole trajectory, sidetracking, well track control and drilling fluid in drilling process.