ONGC conducted the spudding of the first well in the DWN 98/2 Block in April 2018. Image courtesy of ONGC.
ONGC engaged Vantage Drilling for the supply of Platinum Explorer drill ship for the drilling at Cluster 2. Image courtesy of ONGC.
Fugro Voyager was used for conducting site investigations at the Cluster 2 field. Image courtesy of Maasmondmaritime.

Cluster 2 field is an oil and gas field located in Block KG-DWN 98/2 in the Bay of Bengal, on the east coast of India. Oil and Natural Gas Corporation (ONGC, a state-owned company, is currently operating the block.

The Cluster 2 field is divided into two blocks namely 2A and 2B, whose development is estimated to cost approximately Rs340.12bn ($5.07bn). The field is expected to produce 23.52 million metric tonnes (Mmt) of oil and 50.70 billion cubic meters (bcm) of gas.

The first well at the KG-DWN 98/2 block was spud in April 2018, while first gas is expected to be produced in June 2019. The first oil is anticipated to be produced in March 2020.

The project development is expected to be completed by June 2020.

KG-DWN 98/2 block location and geology

The KG-DWN 98/2 block is situated offshore the Godavari River delta in Bay of Bengal. It is located 35km off the coast of Andhra Pradesh in the east coast of India, in water depths ranging from 300m to 3,200m.

The block extends in 7,294.6km², with exploration in the region being focused on the thick Tertiary passive margin system.

The offshore portion of the tertiary basin comprises depositional systems ranging from shore-face through to deep-water submarine fan sandstones.

Cluster-2 field reserves

The Cluster 2A is estimated to contain reserves of 94.26Mmt of crude oil and 21.75bcm of associated gas, while Cluster 2B is estimated to host 51.98bcm of gas reserves.

The Cluster 2A will be installed with 15 producer wells and 12 water injection wells with a peak water injection rate of 9,400m³/d. It is anticipated to produce 77,305 barrels of oil per day (bopd) and associated gas at a rate of 3.81 million metric standard cubic meters per day (Mmscmd).

The Cluster-2B is expected to produce free gas of 12.75Mmscd from eight wells and has a 16-year life.

The daily production of crude oil and natural gas from the Cluster 2 field is equivalent to 16.89% and 27.60% of ONGC’s production capacity in 2016.

Cluster 2 development details

The Cluster 2 development involves the commissioning of 35 wells including 15 oil-producing wells, 12 water injection wells, and eight gas-producing wells.

Infrastructure of the project will include a floating production storage and offloading (FPSO) vessel, a gas processing platform connected to a living quarter platform, and ten manifolds along with riser base manifolds.

Oil from the fields is proposed to be transported to the FPSO through a 21.5km-long dual pipeline having 18in diameter. The oil and associated gas will be processed at the FPSO, which will be positioned at a water depth of 413m, while the oil will be transported to an onshore terminal.

A 430km-long subsea pipeline, with diameter ranging from 6 to 22 inches (in), and 150km of umbilicals will be used.

A 20in diameter subsea pipeline will be used to convey the hydrocarbons from the fixed platform, while a 22in diameter pipeline will be used to carry the hydrocarbons from the FPSO to the landfall point. The hydrocarbons reaching the landfall point will be further conveyed to the Odalarevu onshore terminal.

Contractors involved

ONGC awarded the contract for conducting geotechnical site investigations at Cluster 2 to Fugro in July 2016.

Fugro Voyager, a deep water geotechnical vessel, was used as part of the site investigation. Platinum Explorer drillship from Vantage Drilling will be used for drilling the wells.

The consortium of Sapura Fabrication and Afcons Infrastructure is responsible for the construction of the central processing platform and living quarters of the block, under an engineering, procurement, construction, installation, and commissioning (EPCIC) contract.

In May 2019, ONGC awarded the contract for charter hire and operations of a FPSO to Shapoorji Pallonji Bumi Armada Godavari (SPBAG). SPBAG is a joint venture between Bumi Armada and Shapoorji Pallonji Oil & Gas.

The FPSO will operate at Cluster 2 for a period of nine years and is worth approximately RM8.8m ($2.1bn).

The consortium of BHGE, McDermott, and L&T hydrocarbon was awarded the contract worth Rs117.4bn($1.69bn), in October 2018, for the supply of subsea production systems, subsea umbilicals, risers, and flowlines for the Cluster 2 field development.