CNOOC Ltd. said it has derisked exploration prospects in the ultra-deepwater Globigerinid limestone in Pearl River Mouth basin offshore China.
The operator drilled a natural gas well in carbonate rocks in the Liwan 4-1 structure in Baiyun Sag, the largest hydrocarbon-rich sag in the basin, about 300 km southeast of Shenzhen in water depth of about 1,640 m, the company said in a release Sept. 10.
The well was drilled to a vertical depth of nearly 3,000 m, completed at a depth of about 4,400 m, and encountered a gas pay zone of about 650 m in the horizontal section.
A well test produced 430,000 cu m/d of absolute open flow natural gas, showing promising exploration prospects in the ultra-deepwater Globigerinid limestone, the company said.
The discovery is close to the existing Liwan3-1 gas field production infrastructure which could be utilized to develop the new discovery.
