CAUVERY BASIN

Cauvery basin is the southernmost of the four sedimentary basins located along the eastern margin of India. It encompasses an area of about 25000 sq.km onland and 35000 sq.km. in the offshore upto a bathymetry of 400 m. It is bounded in the south by the Sri-lanka basement massif and in the north and west by the Indian Craton. The basin has been differentiated into NE-SW trending basement horsts and grabens formed during the rifting phase in late Jurassic-Cretaceous. Later movements in post rift phase led to a tilting of the basin due east and a progressive easterly shift of depocenters.

This block extends over an area of 81 sq. km. and contains PY-3 field (core area), which has been on production since 1997 using a floating production system and offshore storage tanker. All the crude oil is sold to Chennai Petroleum Corporation Limited (CPCL), the Government’s nominee, at a price linked to Brent. 

During 2005-06, the PY-3 Consortium acquired new 3D Seismic data. Based on interpretation of new 3D data and revised Geological and Reservoir Modeling, the JV Consortium shall consider drilling additional wells to enhance production.

This block extends over an area of 75 sq. km. and is located about 30 km. north of PY-3 field. This block contains the PY-1 basement gas field. The proven gas reserves in the field are mainly contained in the granitic basement structural high, which was moulded into a series of hills and ridges during several million years of weathering and erosion.

The detailed technical work (both subsurface and surface) leading to a revised plan of development (RPoD) was completed and the company has secured approval for it from DGH on a fast track basis. This RPoD envisages development of basement gas reserves by drilling 3 extended reach horizontal wells from a fixed well head platform and resultant gas transported to an onshore delivery point by way of an offshore pipeline. The Company has commenced the implementation of the RPoD and completed the Geophysical and Geo-technical survey work as well as initiated the detailed engineering work for the Onshore and Offshore facilities. The Company has successfully drilled and tested the first PY-1 producer well (Earth) and suspended for future tie-back to offshore platform. Drilling high angle / horizontal well in fractured granetoid basement for gas was the first of its kind in India.The company has drawn plans to tie back this well and drill two more high angle /horizontal development wells.The project is expected to be completed in the year 2009 and soon after that the production will be started.