Research on the application of key technologies for drilling of large displacement wells in Panyu oilfield, Nanhai

In the development of a marginal oil field located in the South China Sea, seven large displacement wells were drilled utilizing existing platform infrastructure. The drilling process encountered several technical challenges, including control of shallow formations, poor drillability of limestone interlayers in deeper strata, and difficulties associated with wellbore cleaning. To address these issues, a range of advanced drilling technologies were implemented throughout the operation. These included cone bit combined with large-angle motor and hydraulic oscillator for directional drilling, PDC bit with high-performance motor and rotary steerable acceleration systems, as well as multi-activation bypass circulation valve technology. The operational outcomes demonstrate that the Ø406.4 mm wellbore reached a maximum inclination of 76.5 degrees upon completion. The mechanical drilling rate for the Ø311.2 mm wellbore increased by 43 percent. Casing was successfully deployed to a depth of 6114 meters using floating rotation technology. The Ø215.9 mm wellbore maintained full-section equivalent circulation density fluctuations within a narrow range of 0.03 g/cm³. Technical challenges such as differential sticking, lost circulation control, and circulation displacement limitations associated with small-diameter tools were effectively mitigated. These findings indicate strong application potential for key large-displacement well drilling technologies in offshore oil field operations.