KG-DWN-98/1 (KG-D6), Bay of Bengal, India

The 8,100km² block KG-DWN-98/l (KG-D6) lies in the Krishna-Godivari basin, Bay of Bengal, on India's east coast. The seabed slopes sharply causing water depths to vary between 700m (2,297ft) and 1,700m (5,577ft). The field is operated by Reliance Industries (90%) on behalf of Niko Resources (10%). Block reserves have been put at around 14,126 billion cubic feet.

The first three discoveries (Dhirubhai-1, Dhirubhai-2 and Dhirubhai-3) have estimated gas reserves of seven to eight trillion cubic feet. In March, the deepwater rig Discover 534 discovered Dhirubhai-4, with in-place gas volumes of 1,700 billion standard cubic feet (bcf).

The $3.3bn phase one comprises development of Dhirubhai-1 and Dhirubhai-3 by June 2008 with peak output of 1.4 billion cubic feet a day. The second phase, which will use a fixed platform on the continental shelf to exploit deeper water discoveries, could boost production from the block to 3.5 billion cubic feet a day of gas. An oil find was also made in the Mesozoic section of well Dhirubhai 36.

SUBSEA EQUIPMENT

This fast-track development will involve one of the biggest and most complex underwater installation campaigns ever. Aker Kvaerner Subsea is responsible for the complete subsea production system in a $400m Engineering, Procurement and Construction (EPC) contract.

Because of the high flowrate potential, the 55t trees will have a 127mm and 178mm bore. The subsea contract is based on 19 subsea trees tied into six six-slot production manifolds weighing 225t each. The longest tieback will be 6.4km. From these manifolds, production will flow through in-field pipelines to the 370t Pipeline End Manifold (PLEM). The longest manifold tieback is 6.8km. The PLEM has been designed to accept additional pipeline tie-ins.

The umbilical distribution hub weighs 170t and there are three 110t (each) subsea distribution assemblies. The 32 lengths of steel-tube umbilical total 101km and there is also 57km of electric power cable. Finally, there is a comprehensive subsea control system.

A pair of 10km 24in production lines will link the PLEM to a Control and Riser Platform (CRP) located in 100m of water. Compression facilities will ease the anticipated reservoir pressures drop two to three years after start-up. Gas export will use three 24in lines running 25km from the CRP platform to shore where gas will be routed to the offshore terminal at Kakinada. The MEG used to prevent hydrates will be reprocessed in a closed loop in a system provided by Aker Kvaerner.

KG-DWN-98/L (KG-D4) PLATFORM JACKET

The platform jacket was manufactured as part of an engineering, procurement, construction, and installation contract by J Ray McDermott. The 9,015t jacket was built at J Ray's Morgan City, Louisiana, fabrication facility, with the piles and topsides being fabricated at the company's Jebel Ali facility in the United Arab Emirates.

At Pascagoula, Mississippi, the jacket and cargo barge will be loaded onto a Fast Transport Vessel (FTV) for a 46-day journey through the Suez Canal to the marine and fabrication base on Batam Island, Indonesia.

The jacket and cargo barge will then be towed for approximately 12 days to India. Once the jacket and topsides are installed, hook-up will begin, with expected completion in early 2008.

DeepOcean won a $166m contract three-year contract to provide a multi-purpose subsea support vessel and related services.

The REM Etive will be deployed under a commercial agreement between DeepOcean and TS Marine to support development.

The vessel will begin installation activities in 1,200m of water on the subsea wells and six manifolds. The Etive will be used for installation, commissioning, and inspection / maintenance / repair, having two work-class ROVs, crane capacity, and an active heave compensated winch system.