China National Offshore Oil Corporation (CNOOC) has commenced full operations of the secondary development project at the Liuhua Oilfield. 

The Liuhua Oilfield project, located in the Pearl River Mouth Basin in the northern part of the South China Sea, is reputed to be the country’s largest offshore reef limestone oilfield by proven geological reserves. 

It is China’s first deep-water oilfield, producing more than 20 million tonnes (mt) of crude oil since it was commissioned in 1996, reported Chinese news agency Xinhua. 

CNOOC estimates that approximately 140mt of reserves remain, prompting the launch of the secondary development phase to access these resources. 

The current phase of the project covers the Liuhua 11-1 and Liuhua 4-1 oilfields, located at an average water depth of around 305m.  

The development includes 32 production wells. 

According to CNOOC, the first group of wells began operating in September last year and daily crude oil output has increased to a record 3,900 tonnes (t). 

CNOOC recently started production at the Weizhou 11-4 oilfield adjustment and satellite fields project in the Beibu Gulf Basin in the South China Sea. 

The Weizhou 11-4 project is located in waters with an average depth of 43m and uses nearby existing facilities. 

The project includes a new unmanned wellhead platform and a central processing platform, which are connected to an existing platform by a trestle bridge. 

CNOOC plans to drill 35 development wells at the Weizhou 11-4 project, with 28 designated as production wells and seven as water injection wells. 

The company expects the project to reach a peak output of approximately 16,900 barrels of oil equivalent per day by 2026, producing light crude oil.