Offshore West Bengal, believed to be a good prospect for natural gas because of its proximity to the gas discoveries in Bangladesh, is undergoing drilling for the first time. Oil and Natural Gas Corporation has begun drilling in a shallow water block (WB-OSN/200/1) in Sunderbans.
The company plans to spend Rs 600 crore (Rs 6 billion) in exploring the block which it bagged in the third round bidding under the New Exploration and Licensing Policy.
ONGC had been planning to drill well in the block for some time now but finding a rig for the purpose was difficult, said ONGC chairman Subir Raha. It finally got a rig from multinational Transocean after one and a half years and two rounds of tendering.
The drilling site is 70-80 km inside the Bay of Bengal at a depth of 10 metre. Rigs for such drilling should be capable of working through sediments which are present in large quantities in shallow waters.
Raha said they would start drilling in the Mahanadi block towards winter. Drilling in the block was delayed due to rigs being deployed in the Krishna-Godavari.
ONGC had spent Rs 175 crore (Rs 1.75 billion) for survey and data acquisition and another Rs 400 crore (Rs 4 billion) would be required for drilling four wells.
Results from the first well drilling would be known in about four to six months. Raha said the block holds "promising prospect" especially because gas discoveries in Bangladesh are not very far from the site.
Indications are that there is more of gas though there though possibility of finding oil is not denied. ONGC had earlier drilled about 47 onland wells in West Bengal. It had also taken up drilling in Contai, about 200 km from Kolkata in July 2003, at village Gobindopur.
The drilling took 60 days. Second round of seismic and pre-seismic studies would be taken up soon, said a company executive. The Contai block is a pre-NELP block which was given to ONGC on nomination basis.
ONGC is also exploring for coalbed methane in the Raniganj Block of West Bengal. Three blocks had been curved out in Raniganj sub-basin for exploration.
