As the tanker "Beihai Kaituo" slowly cast off its moorings and departed, "Hai Kui Yi," Asia's first cylindrical FPSO (floating production, storage and offloading unit) that has been in operation for just two years, successfully completed its 53rd crude oil offloading operation on October 3, bringing cumulative production and export of crude oil from the Liuhua oilfield redevelopment project past 2 million tonnes.

This milestone signals that China's deepwater mature oilfield redevelopment model has withstood the test of continuous production in real-world conditions, providing a replicable practical template for economical development and production enhancement of complex deepwater reservoirs.

The Liuhua oilfield is located in the Pearl River Mouth Basin, approximately 240 kilometers southeast of Shenzhen, with an average water depth of about 305 meters, and consists of the Liuhua 11-1 and Liuhua 4-1 fields.

The project relies on coordinated operations between the "Hai Kui Yi" FPSO, the "Hai Ji Er Hao" platform and subsea production systems, building a full deepwater production chain encompassing "subsea oil extraction 鈥?platform pre-treatment 鈥?FPSO deep processing, storage and offloading," achieving full independent controllability.

The project has brought 32 production wells into operation, with peak daily crude oil output reaching 3,900 tonnes.

The Liuhua oilfield is China's first deepwater oilfield and also the reef limestone oilfield with the largest proven geological reserves offshore China.

Deepwater reef limestone reservoirs are globally recognized as one of the most difficult reservoir types to develop. After more than 20 years of development, the Liuhua oilfield's recovery factor remains below 20%, with approximately 140 million tonnes of reserves still untapped.

CNOOC's research team has explored and established a technical system for stabilizing oil production and controlling water cut in offshore reef limestone reservoirs, driving a significant reduction in the comprehensive water cut of development wells compared to design levels, greatly enhancing recoverable reserves and recovery factors, and extending the oilfield's production life by 30 years.

The "Hai Kui Yi" has unique offloading conditions, lacking the weathervane effect of conventional ship-type FPSOs, with limited space for attitude adjustment. Moreover, based on the prevailing monsoon wind directions in its operating area, dual offloading points have been set up in the northeast and southwest, imposing stringent requirements on tanker positioning, berthing and hose connection.

CNOOC International Trade's Beihai Shipping Company carried out specialized modifications to the existing tanker "Beihai Kaituo," installing a bow loading system on a conventional tanker for the first time in China, enabling hose connection under complex sea conditions, dynamically switching between two offloading points, fully utilizing offshore operation windows, and achieving a maximum single-voyage transport capacity of 450,000 barrels of crude oil, ensuring stable onshore delivery of crude from the "Hai Kui Yi" and advancing full-chain independent controllability of deep-sea oil and gas "extraction 鈥?storage 鈥?transportation."

The cumulative crude oil offloaded by the "Hai Kui Yi" surpassing 2 million tonnes marks the successful real-world validation of the "deepwater jacket platform plus cylindrical FPSO" deepwater oilfield development model under long-cycle, high-load and complex sea conditions, forming a mature, reliable, replicable and promotable "China Solution" for deepwater oil and gas development.

Next, the Liuhua oilfield production team will continue to diligently carry out refined operation and maintenance of deepwater equipment and precise dynamic regulation of reservoirs, deeply tap the potential for stable and increased production, and steadily unleash the oilfield's high-quality production capacity.