Technical difficulties and countermeasures in well control of deepwater drilling in the South China Sea

Due to the differences in sedimentary environment, deepwater drilling environment, and well control equipment of deepwater strata, the well control of deepwater drilling is trapped in many problems such as seabed instability, low formation fracture pressure, narrow formation pressure vessel, and the presence of shallow gas and shallow flow, gas hydrates, and subsea low temperature. Building on a full investigation about well control of domestic and foreign deepwater drilling and considering the characteristics and difficulties of well control of deepwater drilling in the South China Sea, a targeted solution is proposed based on the recent deepwater drilling design and operating experience and a detailed analysis of existing problems in well control of deepwater drilling, such as narrow formation pressure vessel, difficult overflow monitoring, difficult and long well killing operation, complex well control equipment, and the presence of hydrates. Specific measures about deepwater well control are also provided with the deepwater wells in the South China Sea as an example. The understanding and measures presented in this paper may provide a reference for the well control operations of deepwater drilling in the South China Sea.