Belford Dolphin makes first discovery for ONGC

Vol 9, PW 19 (12 Jan 06) Exploration & Production

Dolphin Drilling drillship Belford Dolphins uninterrupted run of dry holes for ONGC is about to end with its current well in the eastern offshore - causing much excitement within ONGC.

Belford Dolphin was first deployed in November 2003 at a location in the western offshore and later in the eastern offshore. She is now sitting in 1200 metres water depth at location U-1 on NELP-II block KG-DWN-98/2, where Cairn Energy holds 10% participating interest.

The well was spud in the first week of December and target depth of 2424 metres was reached in the last week of the same month at the end of a 20-day drilling programme that went smoothly. Even before drilling began ONGC was confident that U-1 would become Belfords first discovery well.

Says a source: The seismic attributes were good; the structures looked good and there were good signatures as well. Logging results after target depth was reached vindicated ONGCs initial optimistic assumption.

Gas shows were reported after 2200 metres, says a source. One promising sand zone, we hear, is about 20 metres thick.

As expected, these have turned out to be channel sands. From 8th January, ONGC was scheduled to carry out a drill stem test of one zone between 2200 metres and 2250 metres.

ONGC plans to test three intervals together, we understand. Testing is expected to take about 15 days.

Only in one respect was ONGC wrong about the expected discovery at U-1. Before drilling, it believed the sand thickness was 80 metres.

The U-1 prospect was believed to be much better than the A-1 prospect (both on KG-DWN-98/2), says a source. It is now turning out to be the reverse.

Present indications are that the U-1 prospect will be similar to the Vashishta gas discoveries reported last year by Discoverer Seven Seas.

LNG Summit