Key Technologies for Drilling and Completing Horizontal Wells with Ultra Long Horizontal Section of Sulige Tight Gas Reservoir

Abstract

Aiming at the technical difficulties such as high circulating pump pressure, high friction torque, low ROP, difficulty in hole cleaning and running in completion casing string running in the ultra-long horizontal section of tight gas reservoir in Sulige Gas Field, this paper analyzes the drilling technical difficulties in the ultra-long horizontal section from the aspects of safe extension of the long horizontal section, hole cleaning, friction and drag reduction and safe running of the completion string, such as optimized allocation of high-efficiency drilling equipment, optimized design of well trajectory, optimized application of drilling acceleration tools, RSS technology, high-efficiency, strong inhibition lubrication water-based drilling fluid and rotary guide shoe + casing floating running technology. The key technologies of drilling and completing ultra long horizontal well for tight gas reservoir in Sulige Gas Field have been formed, which have been applied in 2 wells, with an average well depth of 7 027 m, an average horizontal section length of 3 719.5 m, and drilling cycle of 50.93 d. Between them, Jing50-26H1 Well, TD depth is 7 388 m with horizontal section length of 4 118 m, created two records of the deepest well in Changqing Oilfield and the longest horizontal section of onland oil and gas wells in China. The research and application show that the key technologies provide technical support for efficient exploration and development of tight gas reservoir in Sulige Gas Field, and also provide reference for safe and efficient drilling of ultra long horizontal section well in domestic tight gas field.