GSPC sets 28th March TD deadline for third KG well

Vol 8, PW 25 (23 Mar 05) Exploration & Production

Gujarat Petroleum hopes to reach Target Depth by (Monday) 28th March at its third exploration well at KG-OSN-2001/3 offshore Krishna Godavari.

Spud around 17th January, TD for this well is 5000 metres, where it will reach Lower Cretaceous sediments. These sediments were deposited around 90 million years ago, we are told.

This is the first time these sediments will be reached in the eastern offshore. All discoveries so far in this area have been at the (younger) Pliocene and Miocene levels.

PETROWATCH learns that around 19th March operator GSPC lowered a 9 5/8-inch casing using Saipem jack-up rig Perro Negro 3. It will later lower the 8.5-inch casing (7-inch liner) to target depth.

GSPC had drilled to a depth of 3800 metres by the middle of this month, despite encountering several technical and geological problems along the way. Progress was slow during the first fortnight of March, we learn.

Only about 200 metres could be drilled. This was because the drill pipe got stuck at 3360 metres.

GSPC then sidetracked the well instead of carrying out a fishing operation. The pipe was left in the hole and was topped with hard cement which was meant to be harder than the formation.

But every time GSPC tried sidetracking, the drill bit would come back into the hole because the cement turned out to be softer than the formation. This problem was eventually tackled and sidetracking was successful at the fourth attempt.

Despite setbacks, GSPC decided to go ahead because this well, unlike the previous two, shows promise of being a gas discovery. GSPC has been recording gas shows throughout the drilling, from about 300 metres onwards.

We understand the gas shows were between 20 and 30% and at hydrostatic pressure. Three major prospective zones have been found within a depth of 2600 metres.

Each of these zones is about 10 metres thick, we hear. There are also smaller zones of about two or three metres thickness.