Technical Progress and Development Consideration of Drilling and Completion Engineering for Ultra-Deep Wells in the Shunbei Oil & Gas Field

The Shunbei Oil & Gas Field possesses abundant oil and gas accumulations, however, for its ultra-deep carbonate reservoirs, drilling and completion encounter problems such as lost circulation, wellbore instability, and high-pressure brine intrusion due to complex geological conditions. Therefore, seeking proper drilling and completion technology system for ultra-deep wells is the key point to accelerate field development. In this paper, the drilling and completion technology system for the ultra-deep wells in the Shunbei Oil & Gas Field was formed with technical breakthroughs and field practices, including ultra-deep well casing program optimization, key technologies to increase the rate of penetration (ROP), technologies for preventing and controlling circulation loss, long open hole leakage prevention and small clearance cementing technology, directional drilling technologies for ultra-deep slim holes, and completion technologies for ultra-deep wells in fractured-vuggy reservoirs. Meanwhile, some unresolved urgent challenges were defined, such as the further optimization of casing program for ultra-deep wells, solutions for severe lost circulation problems in the Permian and Silurian, safe drilling technologies for deep wells in the fractured belt, downhole equipments and tools for high temperature and high pressure (HTHP) wells, and safe drilling technologies for fractured reservoirs. Accordingly, development suggestions were proposed, including enhancing the integration of geology and engineering, strengthening the research on loss circulation control and anti-sloughing technologies, facilitating the application of new technologies and new tools, and reinforcing the research and development of high-end equipments and special materials and devices. These suggestions can further spur the rapid innovation of drilling and completion technologies for ultra-deep wells in the Shunbei Oil & Gas Field and achieve efficient exploitation of ultra-deep carbonate reservoirs.