The Staged Completion Technology for Ultra-Deep Wells in Shunbei Oilfield

The multi-fault and multi-grating reservoirs in the Shunbei oilfield have developed multiple fractures, each with one or more grating-like reservoirs. The reservoirs are highly separated, requiring the use of multiple fractured reservoirs through segmented completion to enhance well productivity. Through optimizing the formulation of rubber materials and vulcanization processes, as well as mechanical structure optimization, key tools for segmented completion such as high-temperature and high-pressure open hole packers, ball-throwing grading sliding sleeves, differential pressure sliding sleeves, and completion packers have been developed. Based on the research and development of amphoteric acid thickening agents and organic-inorganic high temperature resistance double crosslinking agents, a high temperature resistance crosslinking slow acid system has been developed. Using the differences in viscosity and density of different fracturing fluids and acid liquids, a remote communication acid fracturing etching deep acid fracturing process has been formed. Based on the research and development of key completion tools, high temperature acid liquids, and acid fracturing processes, a segmented completion technology for ultra-deep wells in the Shunbei oilfield has been formed by integrating geological and engineering factors, and it has been applied in 12 wells. The results show that the open hole packers, ball-throwing grading sliding sleeves, and differential pressure sliding sleeves can withstand temperature of 180 °C and pressures of 90 MPa, with segment levels up to 5. The crosslinking slow acid system can withstand temperature of 180 °C, with viscosity increased by more than 2 times and acid rock reaction rate reduced by more than 20%. The penetration distance of acid liquids has been increased from 100 m to 120 m. The maximum segment level applied on site has reached 4, with packers down to 8833 m deep and the highest temperature of 182 °C. After fracturing, the production rate increased by 20% compared to neighboring wells on average. Three wells including SHB4-5H reached a daily production of 1000 tons, and the goal of high production with few wells was achieved.