ONGC to Invest Marginal Field Offshore Mumbai

ONGC will invest Rs 310 crore in development of the D-1 marginal field offshore Mumbai that will begin oil production in March 2005.

The field, which is estimated to hold 19 million tons of crude oil reserves, will produce 4.57 million tons during its 10 year production life lasting 2014-15, company sources said.

The Rs 310.32 crore project includes construction of a single deck water injection platform and the drilling of six wells in the first phase. The platform shall be ready by December 15, 2004 and oil production is likely to commence from March 15, 2005. Initial oil production rate will be 1200 cubic meters per day.

In phase-II, six wells shall be drilled during 2007-08 and March 2009, after which oil production rate would jump to 2,188 cubic meters per day.

The D-1 structure, a marginal field located in Mumbai Offshore Basin at a distance of around 200-km southwest of Mumbai, in water depths of 85-90 meters was discovered in 1976.

The field, with an aerial extension of nearly 255 square kilometers, has two separate culminations -- the North and South -- with majority of oil being confined to the latter. The present development is confined to the Southern culmination.

The six exploratory wells drilled so far, barring one, has resulted in commercially exploitable oil production from 5 wells ranging from 1600 barrels per day to 4000 barrels per day.

The D-1 field is isolated from the existing infrastructure at Mumbai High and hence was required to be developed on stand-alone basis. The water depth of D-1 field is also at an upper limit of any jackup facility.

"Due to these constraints, efforts were made from time to time to conceptualize a viable scheme to develop D-1 field for last many years. Finally a techno-economic scheme has been conceptualized by considering water-injection and installation of Electrical Submersible Pumps as a viable Artificial Lift mode, right from the initial stage, for maintenance of reservoir pressure and productivity," sources said.

A 12 slot platform with water-injection module facility accommodating Electrical submersible pumping package, bridge-connected to process facility has been envisaged for development of D-1 field structure.

The Sagar Lakshmi jackup is being modified to process D-1 oil, and transport it through a 1.5-km pipeline storage in a tanker.