GSPC is expecting a major oil find at CB-ONN-2000/1

Vol 10, PW 21 (22 Feb 07) Exploration & Production

GSPC’s optimism about NELP-II onland block CB-ONN-2000/1 near Ahmedabad is turning out to be fully justified.

An industry source tells PETROWATCH that GSPC could be on the verge of making its biggest ever oil discovery on this block after having drilled the two wells committed in Phase-III of the exploration period. One of these wells was dry, but the second one, Ambheti, was successful.

Drilled to TD of 3200 metres using a 750-horsepower rig, oil shows were recorded at 3150 metres downward, almost all the way to the final depth. “Usually a 1000-horsepower rig is used to drill to more than 3000 metres depth, but GSPC managed to get this done with a 750-hp rig,â€‌ says a source.

“This is an achievement.â€‌ Testing will begin immediately, once the workover rig hired by GSPC is deployed on location.

“Testing should take another week or so,â€‌ says a source. “GSPC might perforate just one interval.

â€‌ Based on logs, GSPC estimates that Ambheti holds about 40 metres oil pay. “This is the thickest pay encountered on this block,â€‌ we hear.

The previous major discovery on this block, PK-2, had pay zone thickness of between seven and nine metres. GSPC’s five-year exploration period at CB-ONN-2000/1 ended on 6th January 2007.

Normally, an exploration period is for seven years but GSPC offered a five-year exploration period in the hope of getting more marks – and the block - in the bidding round. Despite offering a five-year exploration period, GSPC sought a two-year extension from the DGH.

“This was rejected outright on the grounds that the PSC did not provide for such an extension,â€‌ says a source. At the end of Phase-I and Phase-II, GSPC returned half the block to the government.

After Phase-III it can retain only the discovery and appraisal areas. GSPC and GAIL each hold 50%.