Drilling technology for HTHP exploration in South China Sea and its prospect

The HTHP (high temperature and high pressure) areas in the Ying-Qiong Basin, northern South China Sea have immense exploration potential of natural gas resources. However, these areas are geologically characterized by high temperature, high pressure, multiple pressure steps and narrow safety density window, and HTHP well drilling engineering design and operation are faced with huge challenges. Based on over 30 years’ technology research and practical operation of 50 HTHP wells in this sea area, the key drilling technologies suitable for HTHP natural gas exploration in South China Sea are developed, and they are multi-mechanism formation overpressure prediction, high-temperature drilling fluid, pressure stabilization and channeling prevention cementing, safe drilling of narrow pressure window, and HTHP integrated drilling and ROP improvement. By virtue of these technologies, the drilling difficulties of HTHP exploration in South China Sea are solved, and the drilling operation is carried out safely and efficiently. This complete set of proven safe and efficient drilling technology system and management model for offshore HTHP exploration wells provides the reference for the drilling offshore HTHP wells in petroleum industry.