High hopes at Oil India for gas in Brahmaputra River

Vol 8, PW 16 (03 Nov 04) Exploration & Production

Oil India has high hopes about the prospectivity of the Brahmaputra riverbed in the countrys northeast.

Over the past two years Indias junior state-owned explorer has carried out exhaustive geological evaluation of both banks of the river and believes the Brahmaputra, which originates in the northeast and flows south west, is a high risk, high reward area. Oil India tells us its interest in the riverbed stems from evaluation of its recently discovered Baghjan gasfield and the North Chandmari oil and gasfields.

Both fields are on the southern bank of the Brahmaputra and lie parallel to the river, we learn. We think similar fields lie below the Brahmaputra.

Our fields along the Brahmaputra are egg shaped. Similar shaped fields are likely below the riverbed.

Oil India believes the thickness of the sands and reservoir increases north along the Brahmaputra. The sands are also cleaner and more porous.

Some of these new Lower to Middle Eocene formations are hydrocarbon bearing. We are told the kitchen for hydrocarbon generation in the Brahmaputra riverbed lies in the south and southwestern part of the river and hydrocarbon migration is towards the north and northeast.

We are finding newer formations and the prospectivity of the new plays and the thickness of the reservoirs seems to increase. Oil India expects to find gas in the Brahmaputra.

But exploring the river will be tough. During monsoons, it often overflows, with major floods, destruction and loss of lives in large parts of Assam and neighbouring states.

At some places the river is between 25 and 30-km wide. It presents a lot of challenges, we are told.

It is a very difficult area to work in and well need specialised equipment and technology. Oil India is not so upbeat about the northern bank of the Brahmaputra where it has drilled five dry holes.

We are ending our operations along the northern bank, the company tells us. We dont expect any hydrocarbons there.