Cairn mobilises third Weatherford rig at Mangala

Vol 13, PW 16 (28 Jan 10) Exploration & Production

Most companies use Enhanced Oil Recovery (EOR) techniques when their assets are in decline – but not Cairn India! PETROWATCH learns Weatherford has begun assembling a newly arrived rig for Cairn’s long-awaited EOR â€کpilot’ at Mangala that will see three observation wells, four water injectors and one producer, pumping out an initial 1500 b/d.

“The first well should be spud in early February,â€‌ Cairn tells us. “The second will be drilled end-February.

â€‌ Cairn is winning plaudits all round for the early use of EOR at Mangala, which began production only in August last year and today pumps out around 25,000 b/d with â€کpeak’ production of 125,000 b/d predicted in ten years. “Cairn is the first company to use EOR so early on in the production stage,â€‌ says an analyst.

“Normally EOR is used when a field is in decline.â€‌ Cairn’s enthusiasm for EOR is easy to understand.

Mangala has a recovery factor of 35% - high by international standards where the norm is 30% or less - but optimists say if results are positive the early use of EOR at Mangala could increase production by as much as 20%. “There are more residual deposits (of oil) at Mangala than new hydrocarbon deposits,â€‌ reports a source.

“If you can recover up to 55% or 60% it would be like discovering another Mangala!â€‌ Cairn’s two-year pilot will see water injection followed by polymer injection and then more water injection before any tangible results can be ascertained. Some admit it is a “big scientific experimentâ€‌ where economic viability is yet to be fully established.

But if successful, Cairn will roll out a â€کfull-field’ EOR programme across Mangala by 2013 and later across Aishwariya and Bhagyam. “Preparation of the EOR development will be in parallel to the pilot,â€‌ adds a source.

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