Engineering Application of Cutting and Retrieving for Riserless Deepwater Subsea Wellhead System
Wu-nian ZHANG1, Yin-ge JIA1, Jing ZHANG1, Jian LIU2, Bo LUAN3
1. Shenzhen Far East Oil Drilling Engineering Ltd., Shenzhen, Guangdong 518068, China 2. CNOOC Research Institute, Beijing 100027, China 3. College of Mechanical and Electrical Engineering, China University of Petroleum, Qingdao, Shandong 266580, China
Cutting and retrieving of deepwater subsea wellhead system are an operation with no riser in deepwater drilling engineering. We introduce the researches, test, and improvement process of all the key equipments of our self-developed outside stretch latch rotary (OSLR) tool. According to the operational statistics of 10 wells and by comparison with foreign technology, it is proved that both of the self-developed deepwater mechanical cutting equipments and the dynamic cutting equipments have reached the level of engineering application. The importance of a rational selection of pump rate and the nozzle of the cutter is also discussed by analysis of force on the blade and the hydraulic design of engineering systems.
