Dependence on Bibiyana threatens gas field structure, energy security

The government's growing dependency on a single gas field --Bibiyana -- to ramp up the overall natural gas output is posing a threat to the field's structure as well as the country's future energy security, industry insiders said.
US oil and gas giant Chevron-operated Bibiyana gas field is currently supplying around 1,200 million cubic feet per day (mmcfd) of natural gas from 21 wells, which is 45.11 per cent of the country's overall natural gas output of 2,660 mmcfd as of March 16, data from state-owned Petrobangla revealed.
Bibiyana, located under block 12 in the country's northeastern region, increased natural gas output to six-fold within the past eight years of operation after initiating gas supply gas in March 2007 at the rate of 200 mmcfd.
The pace of increase in natural gas supply from the Bibiyana gas field was faster in recent times as its production increased by over 200 mmcfd within the past two months from 1,000 mmcfd in January 2015.
The Bibiyana field was supplying around 900 mmcfd of natural gas in October 2014.
Officials said, Chevron Bangladesh has planned to raise natural gas output from the Bibiyana field further as it has submitted a new assessment report to Petrobangla last month estimating an additional natural gas reserve of around 1.5 trillion cubic feet (Tcf) in Bibiyana field.
The DeGolyer and MacNaughton made the estimate on Chevron's behalf and with it, Bibiyana's reserve will stand at around 7.0 Tcf, if the Petrobangla accepts the estimation.
The country's largest gas field was discovered in 1998 with an initial estimated reserve of 2.4 Tcf.
Chevron Bangladesh is currently the largest producer of natural gas in the country, which is supplying around 1,490 mmcfd of natural gas, accounting for over 56 per cent of the country's total supply from three of its onshore gas fields -- Bibiyana, Jalalabad and Moulvibazar -- located in blocks 12, 13 and 14, respectively, in the northeastern Sylhet region, according to Petrobangla data.
The natural gas production from the Bibiyana gas field is now 'overproduction,' said Professor Badrul Imam of the Geology Department of the Dhaka University.
Chevron Bangladesh is putting 'extra pressure' to increase natural gas output from the Bibiyana field.
"The way Chevron is exerting pressure on Bibiyana might damage the natural structure of this precious gas field," he said.
The US firm is putting too much pressure on Bibiyana that natural gas production from some wells there rose as high as 160 mmcfd, which is more than double the maximum gas production from other field, Mr Imam said.
He warned the government of depending too much on the Bibiyana output.
"Any technical glitch in Bibiyana will result in natural gas blackout in the country similar to that of electricity blackout," Professor Imam cautioned.
Overproduction from Bibiyana might lead to a similar situation in the Sangu gas field, which was supplying as high as 220 mmcfd of natural gas several years ahead of its abrupt closure in 2013, he said.
The Bibiyana gas field had already faced halting of production for a brief period on two occasions last year, resulting in abrupt crisis of natural gas last year, he added.
Chevron might use overdependence in 'other ways' to press home their undue demands, he added,
When contacted, Professor M Tamim of the Bangladesh University of Engineering and Technology (BUET) also opined for slowing down of natural gas output from the Bibiyana gas field.
"I think Chevron should not be allowed to increase further natural gas output from Bibiyana," he said.
Another official said due to 'overproduction', the pressure of natural gas in several wells already dropped by 1,000 per square inch (psi) to 2,600 psi from initial pressure of 3,600 psi.
    mazizur.rahman@outlook.com