Liuhua oil field, South China Sea

Liuhua 11-1 is an oilfield in the eastern South China Sea, about 200 kilometres southeast of Hong Kong. Together with the neighbouring Liuhua 4-1 field, it is worked in water about 305 metres deep. It is described as China's first deepwater oilfield secondary development project.

Production under the new project began in September 2024. It uses two main structures: a tall deepwater jacket platform named Haiji-2 and a round, floating oil-factory ship named Haikui-1. The company that runs it is CNOOC. The work shows how engineers build giant machines to pump oil far out at sea, in water hundreds of metres deep.

Two special structures

Haikui-1 is called Asia's first cylindrical FPSO, which stands for floating production, storage and offloading unit. It weighs 37,000 tonnes, is about as tall as a 30-storey building, and can store up to 60,000 tonnes of oil. It is held in place by 12 mooring legs fixed to the seabed with suction anchors. Haiji-2 is a deepwater jacket platform, a steel frame fixed to the seabed that holds up the working decks.

Why it matters

The two fields together are expected to reach about 17,900 barrels of oil equivalent a day at their peak in 2026, with 32 wells. CNOOC says the new design, a jacket platform joined with a cylindrical FPSO, was a first for Asia and cut construction and production costs a lot. Haikui-1 was installed in June 2024, the first time China had installed a cylindrical offshore unit.

On the globe

The toy globe marks the Liuhua oilfield in the South China Sea. Zoom in on the sea to find the round ship and the tall platform.