The Weizhou 12-8 East project is a producing oil field in the Beibu Gulf in the South China Sea, China. The field started production from the first development well A2H in April 2022.

The oil field development project consists of a total of six production wells and the drilling of the remaining five wells is expected to be carried out in 2022.

China National Offshore Oil Corporation (CNOOC) with a 51% stake, Horizon Oil (Beibu) with 26.95%, Roc Oil (China) Company owning 19.6%, and Oil Australia with a 2.45% stake are the development partners of the project. The partners reached a final investment decision on the Weizhou 12-8 East development in October 2020.

Roc Oil is the operator of the Weizhou 12-8 East project during the drilling and early production phase. CNOOC is expected to assume operatorship by the end of 2022.

The Weizhou 12-8 East oil field project is anticipated to achieve an average crude oil production of approximately 4,700 barrels of crude oil a day (bpd) in 2022. It is expected to have a peak production of around 10,000bpd.

Location and site details

The Weizhou 12-8 East oil field development project is located in Block 22/12, Beibu Gulf, South China Sea, China.

The project is situated around 82km offshore Beihai, China and the average water depth in the oil field development area is around 30m.

Weizhou 12-8 East oil field development details

The Weizhou 12-8 East oil field’s first phase development will include the drilling of seven development wells, installation of a self-elevating wellhead supporting platform, and laying of subsea pipeline and cables.

The seven development wells will include six oil production wells and one production water reinjection well.

Five production wells, A2H, A3H, A4H, A5H and ASH, will target the western side of the Jiaowei reservoir, while a production well A1H will be drilled in the Weizhou reservoir.

The Weizhou 12-8 development plan also comprises the A7 well that will focus on an exploration opportunity in the Weizhou reservoir and will be later converted into a production water reinjection well.

An 8km-long subsea export pipeline and a subsea power cable connect the Hai Yang Shi You 163 platform to the existing Weizhou 12-8 West wellhead platform. The crude oil is further transported to CNOOC’s Weizhou terminal utilising the existing infrastructure.

The seven well-drilling campaign for the project commenced in March 2022 and is expected to be completed in July 2022. Further development of the Jiaowei reservoir will be based on the performance of the first phase.

The Weizhou 12-8 East first phase project is estimated to contain gross 2P reserves of 2.3 million barrels.

Hai Yang Shi You 163 platform

The 81m-long, 44m-wide Hai Yang Shi You 163 is a four-legged jack-up wellhead platform designed to operate in a maximum water depth of 45m. The platform weighs more than 7,000 tonnes and has a design service life of 25 years. It is claimed to be the first offshore mobile self-elevating wellhead platform to be designed and constructed in China.

The wellhead platform is used for processing of well stream to separate oil, water and gas; produced water treatment; crude oil production and water injection.

Block 22/12 details

Block 22/12 comprises production areas Weizhou 6-12, Weizhou 12-8 West, and Weizhou 12-8 East covering a total area of 76.2km2. CNOOC is the operator of WZ 6-12 and WZ12-8W developments.

The block commenced production from the Weizhou 6-12 and Weizhou 12-8W oil fields in March 2013. It consisted of two remote wellhead platforms targeting WZ 6-12 and WZ 12-8 West development areas, prior to the commissioning of Hai Yang Shi You 163.

The WZ 6-12 platform is connected to 11 wells, while the WZ 12-8 West platform produces from eight wells.

Contracts awarded

CNOOC Energy Development was contracted to lease Hai Yang Shi You 163 wellhead platform for the Weizhou 12-8 East oil field development project.

China Oilfield Services (COSL) was contracted to drill wells for the Weizhou 12-8 East project. The company mobilised its Strike jack-up drilling rig for the project.