On April 21, China National Offshore Oil Corporation (CNOOC) successfully completed the country’s first operation of simultaneous steam injection into eight wells at the Lyuda 5-2 North Oilfield, marking a new milestone in offshore ultra-heavy crude oil development technology.
Operated by CNOOC Tianjin Branch’s Liaodong Operation Company, the Lyuda 5-2 North Oilfield is located in the Liaodong Bay of Bohai Sea. It features ultra-heavy crude oil with extremely high viscosity and almost solidified form at room temperature — widely regarded as one of the toughest challenges in offshore oil recovery.
As a key site for thermal recovery of ultra-heavy oil in Bohai, the Lyuda 5-2 North Oilfield uses steam injection technology to convert oil into a recoverable resource.
Following the launch of Phase I production in 2022, the oilfield piloted a four-well simultaneous steam injection approach, overcoming challenges such as steam breakthrough and uneven thermal distribution. This raised thermal efficiency by more than 20 percent and laid a technical foundation for scaling up to the eight-well configuration.
In this latest operation, all eight wells were located in the same reservoir horizon. The team precisely controlled steam injection pressure and flow to ensure uniform heating. The total injected steam volume reached 52,800 tons — the highest ever recorded among similar oilfields in the Bohai region — equivalent to the water capacity of 21 standard swimming pools.
Currently, Phase II production facilities are fully operational. The success of the Lyuda 5-2 North Oilfield provides a replicable model for offshore ultra-heavy oil recovery. The broader rollout of large-scale thermal recovery technologies is expected to serve as a new engine driving stable and increased crude oil production.
(Executive editor: Yuan Ting)
