New Delhi: Reliance Industries and its partner BP Plc of UK have spent over ₹ 7,000 crore in prolonging output from the flagging D1 and D3 gas fields in the Bay of Bengal as they prepare new fields that will start production in mid-2020, sources in the consortium said.
In perhaps one of its kind intervention in a deep sea field, RIL-BP has, through the use of a combination of complex techniques, kept the wells flowing at Dhirubhai-1 and 3 (D1 & D3) gas fields in the Krishna Godavari basin block KG-D6, they said.
RIL-BP want to keep the system live till the R-Series and Satellite fields in KG-D6 block are ready to produce. The due plan to use existing facilities to produce 30-35 million standard cubic metres per day of peak output from R-Series, Satellite, and MJ fields.
The D1 and D3 fields, the first of the one-and-a-half dozen gas discoveries in KG-D6 that were brought to production in April 2009, will cease to produce by end-2019. This shutdown will coincide with upgradation, modification, and preparation of facilities and operating system to connect new fields, sources said, adding the R-Series is likely to give first gas in mid-2020 while Satellite and MJ field may begin output in 2021 and 2022.
The partners, they said, have spent over ₹ 7,000 crore in sustaining production from D1 & D3 fields, which otherwise would have ceased to produce much earlier. D1 & D3 witnessed higher than anticipated and sooner than expected sand and water ingress that led to choking of wells after wells since the second half of 2010. D1 & D3 are at the tail-end of their production life and they are being kept alive to preserve the facility for use by the new production from the three projects, sources said.
Besides costing money to first preserve the facilities in case of an early shutdown and later reuse it, a shutdown could have created problems as the system would be idle for too long in the deepwater, they said, adding inlet pressure has been delicately reduced to levels where multiple wells could be kept flowing.
Besides, surfactant is being used to lift water from the wells and gas from MA field is being recirculated to keep the line packed and help lift the gas from the remaining fields. This, they said, can last for only another year—at which point the quantity of gas will be so low, water production will be beyond what the system can manage, and the pressure will be depleted that no more gas can be produced.
Reliance had till date made 19 oil and gas discoveries in the Krishna Godavari basin. Of these, D26 or MA—the only oil discovery in the block—was the first field to began production in September 2008. D1 and D3 fields went onstream in April 2009. MA field cessation expected by September 2018, sources said, adding that the field at its peak had produced 1,08,418 tonnes of oil in May 2010.
Output has been declining since then it produced 0.14 million barrels (1960 tonnes) in the April-June quarter. MA also started producing gas from April 2009, just when D1 and D6 went live. It peaked to 8.4 mmscmd in August 2010 before sand and water ingress forced shutting down of well after well. D1 & D3 field too had a peak that year in March when it touched an output of 61.4 mmscmd. Output thereafter has only declined.
KG-D6 output in April-June averaged at 4.7 mmscmd. This was made up of production from both D1 & D3 and MA fields.
RIL is the operator of KG-D6 block with 60% interest, while BP Plc holds 30% stake. Niko Resources of Canada has the remaining 10%. RIL had in the field development plan for D1 and D3 proposed a capital expenditure of $8.836 billion. For developing Dhirubhai-26 or MA oilfield, it had in 2006 proposed to invest $2.234 billion, which was scaled down to $1.96 billion in 2012.
The fields were in the investment plans supposed to last a minimum of 15 years but have extinguished in exactly a decades time.