Under the background of optimizing project costs and decreasing carbon footprint, CNOOC launched a campaign strategically to explore new offshore records. This paper records how the pilot project of this campaign achieved remarkable success to dramatically decrease operation cycle time and reduce drilling waste discharge with the help of technological innovation and advanced project management.

The innovation to improve drilling efficiency starts from well designing phase. Wellbore geometry is optimized and downsized to smaller hole size to improve drilling rate and reduce drilling waste. A series of innovative modifications are made on both the rig operating equipment and the work process to reduce the operation time. Novel technologies are utilized to reduce drilling cycle time including industry's first definitive dynamic survey-while-drilling service, realtime drilling intelligence service, pulse neutron generator (PNG) enabled multi-function logging while drilling (LWD) platform, and so on. Bit and motor are both optimized to increase drilling speed. To reduce the waste discharge during drilling and completion, a fully closed zero discharge system is employed. Flawless project management also played vital role in the project success.

Totally 23 wells are drilled for this pioneer project. 269.80 days are saved compared with plan and drilling efficiency is improved by more than 58%. Wellbore geometry optimization saves 111.63 days drilling cycle time and reduces 3189 tons waste. 25.94 days are saved by utilizing advanced measurement while drilling (MWD) tool and LWD technologies. More than 14 days are saved by innovative modification on the rig equipment. At least 7 days are saved through optimizing the work process. With the fully closed zero discharge system, 2414 cubic meters drilling fluid is reused and 7040 tons cutting are processed. This project breaks several drilling records in CNOOC.

The novelty of this paper is to provide experiences of utilizing most up-to-date technologies and innovative systematic approach to reduce the drilling cycle and carbon and waste discharge.

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