ONGCآ’s run of dry holes with Belford Dolphin over

Vol 9, PW 21 (09 Feb 06) Exploration & Production

Belford Dolphins uninterrupted run of dry holes for ONGC is over.

There was excitement and celebration on board Belford end-January when ONGC began testing location U-1 on eastern offshore deepwater block KG-DWN-98/2, where Cairn Energy has 10%. ONGC tested one zone around 2200 metres depth.

A 22-metre zone was perforated, we hear. Testing was carried out over seven days, says an industry source.

ONGC used five choke sizes: 12/64-inches, 16/64-inches, 24/64-inches, 32/64-inches and 40/64-inches. The flow rates were very good, we hear.

Initial flow rates were 75,000 cm/d and they peaked to 680,000 cm/d. Surface pressure was 3000-psi.

During testing the well was allowed to flow for three days. The gas was found to be 98% methane and the rest C2 and C3.

Despite rejoicing at Belfords first strike for ONGC, there was some disappointment because the sand thickness turned out to be much less than the 80 metres originally expected. ONGC and Cairn are now evaluating the extent of the discovery.

After finishing testing at U-1, Belford moved to another location also on the same block. Location W-1 was reached on 26th January.

Belford is sitting in 1250 metres water and has been assigned a target of 2400 metres to reach Pliocene era sediments. The 30-inch and 20-inch casings have already been lowered.

Late last week the Blow Out Preventor and the riser were being put into position ahead of drilling. At this location, ONGC plans to lower two more casings: 9 5/8-inches and 7-inches.

Target depth should be reached by 15th February. Industry sources say ONGC believes the W-1 location is excellent.

We are told that ONGC is expecting a big strike at W-1. The seismic attributes are very good.

This location will turn out better than U-1.