The 3D seismic survey area in the prospective northern part of the contract area comprises 824 square kilometres of full-fold coverage, an increase from the previously announced 653sq.km, due to additional lead potential identified on the block.

The survey, being shot by Veritas Geophysical, began on Friday and is expected to take about 30 days to complete.

Once Veritas finishes the acquisition, it will process the survey through to hybrid-pre stack depth migration and supply fast-tracked data two weeks after the survey is done, Nido said.

This will help ensure rapid and efficient turnaround of the interpretation leading to a build of a risked and ranked high-graded prospect inventory, which can start from as early as December, it said last month.

The 3D expanded coverage will deliver an enhanced prospect inventory that includes:

Coron North, an undrilled four-way Malampaya-style structure with reef build-up potential;

deepwater Pagasa turbidite fairway (Princesa fan mound leads);

Coron-1 (previously drilled by Fletcher Challenge in 1993 with an untested possible 120m oil column);

a Coron-Nido interpreted fill-spill chain; and

a Pagasa turbidite feeder system.

Veritas is using its flagship M/V Veritas Viking II 3D vessel to acquire the data.

Yilgarn is earning a 40% stake in the permit by funding the acquisition and processing of seismic data on a 4:3 promote basis and the drilling of one well on a 2:1 promote basis.

The joint venture includes the Philippines National Oil Company.