Abstract: Well Xia 92-H is a wildcat well on the circum-Mahu sag slope belt. The region where the well is located has complex structure and large variation in lateral burial depth of the oil reservoirs, and the wells differ greatly from each other. Conventional technology cannot locate the reservoirs in a timely and accurate manner and cannot ensure that the hole trajectory will be kept in the reservoir, which is not favorable for improving the encountering rate of oil reservoir by horizontal wells and evaluation of reservoir productivity. By building a pre-drilling geologic model, real-time interpretation of MWD data and timely description and optimization of geosteering and wellbore trajectory, the top boundary of the target and landing depth could be effectively determined and 100% of reservoir encountering rate was achieved by horizontal holes, leading to excellent geosteering and trajectory control.