OIL HAS been found in an exploration well in China’s Beibu Gulf, Australian company Horizon Oil has announced.

The WZ 12-10-1 well in the Beibu Gulf block 22/12 found oil in the top of the Jiaowei T42 formation over an interval of 5.5 metres, with high porosity net oil pay of 4.2 metres.

The well was drilled to a total measured depth of 1,406 metres, where granite basement was intersected. No oil pay was interpreted in the deeper Weizhou formation.

The exploration drilling program over Beibu Gulf block 22/12 follows up on earlier exploration discoveries and the subsequent successful development of the WZ 6-12 and WZ 12-8W fields carried out in 2012 and 2013, which have already produced over six million barrels of oil.

The well is located 4.7 kilometres northeast of the existing WZ 12-8W platform and about 2.7 km west of the WZ 12-8E discovery wells, Horizon said.

Following the discovery, a sidetrack (WZ 12-10-1Sa) was drilled to a bottom hole location 340 metres east northeast of the first well to a total measured depth of 1,265 metres 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 metres.

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 27 September 2014.

The discovery will now be evaluated to assess how it may be integrated into the Beibu project, Horizon said.

Rig HYSY 935 will move to the WZ 12-10-2 exploration location to drill the second and last well in this program.

Horizon Oil chief executive Brent Emmett said the discovery added a potentially valuable incremental oil volume to the future WZ 12-8E development project.

“The discovery is timely and will allow the joint venture to evaluate alternatives for development of the WZ 12-8E oilfield,” he said.

Horizon and its subsidiaries hold a 55 per cent exploration interest in the project, with Roc Oil holding 20% and Oil Australia holding 5%.

China National Offshore Oil Company (CNOOC) holds a 51% production and development interest in the project, alongside Horizon (26.95%), Roc (19.6%) and Oil Australia (2.45%).