Aiming at the technical challenges of sand carrying, low success rate of electric logging and bit mud package in directional well drilling of extended reach slim hole in Sulige gas field, a set of radical drilling technology has been found out by optimizing the well structure, section, bit and high-power screw and using large data analysis of drilling.Directional wells with displacement of 1440 meters and displacement vertical ratio of nearly 0.5 have been realized.The drilling speed is slightly higher than that of conventional wells.The cost of footage per meter is 12.5% lower than that of conventional wells, and the cuttings are reduced by about 48%.Extended reach slim wells were developed in Sulige gas field, with remarkable ecological benefits and cost reduction and efficiency increase. It is of great significance for reducing cost and increasing efficiency of this kind of wells.