An initial attempt to test the well earlier in the week was unsuccessful due to mechanical problems, Oil Search said.

The test equipment was then recovered from the well, repaired and re-run in preparation for a second try.

“The operator is currently investigating the operational integrity of the test including the possibility of a mechanical failure,” managing director Peter Botten said.

Nabrajah-8, which is first well in the Nabrajah Basement appraisal development program, is aimed at evaluating a number of zones throughout the Basement section identified from wireline logs and shows while drilling.

Located about 1.6 kilometres east-north-east of Nabrajah-5, Nabrajah-8 was drilled as a near vertical well.

Its objectives were to firstly delineate the height and lateral extent of the oil column encountered by Nabrajah-5 by drilling up to 1,000 metres into the Basement formation. Secondly, Nabrajah-8 was to provide data on the lateral and vertical characteristics of the Basement fracture system.

In April this year, the company announced its Nabrajah-5 well was flowing almost 10,000 barrels from two formations on test.

The participants in the Nabrajah-8 well are: DNO ASA (56.67% and operator), Oil Search (Yemen) Limited (28.33%) and the Yemen Company (15% - carried).