Reduced reserve estimate for 'Ambe' in Gujarat

Vol 6, PW 2 (27 Mar 02) Exploration & Production

CAIRN HAS SHARPLY reduced its proven and probable gas reserve estimate for the 'Ambe' and 'Gauri' fields at its CB-OS/2 exploration block offshore Gujarat.

A source reveals that Cairn has informed the DGH that Ambe holds 36.3bn cubic feet of 'proven gas' and 11bn cf of 'probable gas' in the 'Baba Guru' sands of the 'Ambe Northwest Ridge' structure. It also reckons there's 7.7bn cf of 'probable' gas in the south-west part of 'Ambe'.

Cairn admits that these figures are sharply lower than the initial estimates of between 100bn and 300bn announced to its joint venture partners last January for 'Ambe' and 'Gauri' combined. Cairn admits the current estimates are "considerably below expectations" spelt out in its January letter but "sufficient to go ahead with commercial development".

Cairn has already completed an appraisal programme for 'Ambe' and is not planning any further appraisal to determine commerciality. So what next The company is preparing a commerciality report for joint venture partners and the oil ministry.

Cairn is also planning a development programme for 'Ambe', whose development area has been increased to 789 sq km from 108 sq km following results of 3D seismic. Cairn wants to develop 'Ambe' with a single well (CB-C-1) connected by pipeline to the 'Lakshmi' platform, which sits ring-fenced in the block.

Initial plans are to develop only 'Ambe' but production performance at this and other fields on CB-OS/2 "may provide sufficient information" that could lead to development of satellite structures via single wells linked to the Lakshmi platform.