The WZ 12-10-1 well in China's Beibu Gulf has discovered oil in the top of the Jiaowei T42 formation over an interval of 5.5 m (18 ft), with high porosity net oil pay of 4.2 m (14 ft), Horizon Oil said in a news release.

The well was drilled to a total measured depth of 1,406 m (4,613 ft), where granite basement was intersected. No oil pay was interpreted in the deeper Weizhou formation.

A sidetrack (WZ 12-10-1Sa) was then drilled to a bottom hole location 340 m (1,116 ft) east-northeast of the first well to a total measured depth of 1,265 m (4,150 ft) to investigate the T42 reservoir updip, which confirmed oil in the top of the T42 formation with a (thicker) net oil pay of 5.5 m (18 ft), the release said.

A wireline evaluation logging program, including MDT pressure measurements and formation fluid sampling, has been run, which confirmed the oil pay in the T42 reservoir. The well was plugged and abandoned, as planned, on Sept. 27.
The discovery will now be evaluated to assess how it may be integrated into the Beibu project. Rig HYSY 935 will move to the WZ 12-10-2 exploration location to drill the second and last well in this program, the release said.