Panna holds another 20m-40m barrels in-place oil

Vol 10, PW 6 (13 Jul 06) Exploration & Production

British Gas and partners Reliance and ONGC are considering a new development programme at the Panna oilfield offshore Mumbai following a major but so far unreported oil discovery in January this year.

It was a very significant find, reveals a source. Based on logs we estimate an additional 20m-40m barrels of in-place oil.

Subsequent inquiries by PETROWATCH reveal that on 11th January this year the Ensco-50 rig sitting in water depths of 150 feet spudded exploration well SWP-1 (South West Panna) in the field and encountered two promising hydrocarbon-bearing zones. There was some associated gas but it is mainly an oil discovery, adds a source.

Oil flowed at between 800 b/d to 1200 b/d. We further learn that any development programme would probably require one more production platform and three or four wells.

Drilled to a target depth of 2,180 metres, the well was targeting the Panna Basal Clastics formation and struck lucky. All objectives of the well were achieved, we learn.

Hydrocarbons tested in B-Upper, the A-Zone and Alternations. Further inquiries by this report reveal that the B Upper zone was perforated between 1883 to 1839 metres and measured a stabilised oil flow rate of 823 b/d and gas at 379,000 cf/d using a 32/64-inch choke at a wellhead pressure of 386-psi.

The gas is sour; most gas produced from Panna is sour, reveals a source. The oil was about 32-33 degrees API.

Similar success was recorded during testing of the A-Zone, which was tested between 1807 and 1820 metres and measured a stabilised flow rate of 1239 b/d oil and gas at 980,000 cf/d through a 44/64-inch choke at a wellhead pressure of 304-psi. No oil was recorded during testing of the Alternations between 1714 and 1716 metres and 1807 and 1820 metres.

But gas flowed at a stabilised rate of 136,000 cf/d using a 20/64-inch choke at a wellhead pressure of 504-psi. The SWP-1 well has provided valuable data which indicates that the structure has development potential, we learn.

The joint venture is currently assessing the options and feasibility of a South West Panna development.