An uncontrolled flow of gas started from the Well G-1-9 in the Krishna Godavari basin was noticed on September 1 and the gas leakage stopped on November 7, Minister of State for Petroleum and Natural Gas Panabaka Lakshmi said in a written reply to a question in Rajya Sabha here.
"The leakage of gas from the well has stopped from November 7 and the well has been brought under control on November 29 by placing and latching capping stack assembly," she said.
Since only gas, mainly methane which evaporates rapidly, was leaking there was no resultant contamination in the area, she said.
The sub-sea well, in the G-1 block, is located at a distance of 30 km from the Amalapuram coast in Andhra Pradesh.
"The leakage of gas containing methane was taking place from a temporary abandoned sub-sea well," she said.
The well is located in the G-1 field in Krishna Godavari basin. G-1-9 well was drilled about a decade back and had not been put in production till now. It suddenly started leaking gas.
"ONGC had hired the expert services of Boots & Coots as per agreement with them to handle uch emergencies to stop the leakage," she added.
The company is currently developing KG basin G-1 field along with neighbouring GS-15. Both the fields are marginal or small finds. G-1-9 well was part of this development through which ONGC had planned to produce 2.7 million standard cubic meters of gas and 9,400 barrels of associated oil daily.
Through this, it is targeting to produce 0.982 million tonnes of oil and 5.92 billion cubic meters of gas by 2020-21.
The project at the time of conception in 2003 was to cost Rs 429.82 crore but the cost was subsequently revised to Rs 1,262.93 crore in 2004 and then to Rs 2,218.01 crore in 2010.