35% decline in gas output from Tapti field in 3 yrs

Natural gas production from the BG Group-operated Tapti field off the Mumbai coast has fallen by over 35% in the past three years due to natural decline of the ageing field.

Gas output from the Tapti field dipped from 4,301.12 million standard cubic metres (mmscm) in 2008-09 to 3,184.40 mmscm in 2009-10 and further to 2,778.54 mmscm in 2010-11, Minister of State for Petroleum and Natural Gas R P N Singh told the Rajya Sabha today.

The BG Group holds a 30% stake in the Panna-Mukta and Tapti (PMT) oil and gas fields off the West Coast. Oil and Natural Gas Corp (ONGC) holds a 40% stake in the fields, while the remaining 30% is with Reliance Industries.

Singh, in a written reply to a question, said gas output from the Panna-Mukta field fell by 11.5% from 1,764.95 mmscm in 2008-09 to 1,561.90 mmscm in 2010-11.

"The reasons for the reduction in gas production is primarily due to natural decline of the PMT oil and gas fields, which are matured and ageing," he said.

"Further, in case of Tapti field, under-performance of the reservoir due to premature water ingress in the newly drilled gas wells had resulted in a drastic reduction in gas production from this field," he added.

PMT gas is supplied to GAIL India, Reliance, Gujarat Gas Co Ltd, Gujarat State Petronet Ltd, Torrent Power, Rajasthan Rajya Vidyut Utpadan Nigam Ltd's Dholpur plant and six NTPC power plants (Faridabad, Anta, Auriya, Dadri, Kawas and Gandhar), among other buyers.

"In the past, incidents such as pipeline/riser leakage, failure of single point mooring (SPM) hose, etc, in Panna-Mukta field had led to temporary shutdown of the fields, resulting in stoppage of oil and gas production during that period," Singh added.