CNOOC has completed the second phase drilling program of the Weizhou 12-8E oil field development project in Block 22/12 in the Beibu Gulf offshore China, according to project participant Horizon Oil Ltd., Sydney.
The rig’s release marks the end of a 10-month campaign that drilled and completed 10 WZ12-8E horizontal development wells and one WZ12-8E water disposal well. Additional work in the Weizhou 6-12 field to the north included two WZ6-12 development/appraisal wells and one exploration/appraisal well plus workovers of five existing WZ6-12 wells.
Oil production is averaging more than 19,000 b/d, about 10,000 b/d of which is from the original Beibu fields and about 9,800 b/d from the new WZ12-8E field, Horizon said.
Production has increased by about 4,500 b/d compared with October 2022, prior to the start of the WZ12-8E program.
Production performance has exceeded pre-drill expectations because of longer horizontal production intervals (995 m versus a planned 920 m) and greater offset from the underlying oil-water contact, particularly for the wells in the main Jiaowei field, Horizon said.
The WZ12-8E projected is expected to reach a peak oil rate in January before natural decline begins, and formation water inflow increases. The JV is investigating options to mitigate decline.
CNOOC is operator for the development/production phase with 51% interest. Partners are Horizon (26.95%), Roc Oil Ltd. (19.60%), and Majuko Corp. (2.45%).