Sagar Samrat, ONGC-Commissioning & PGTR

Sagar Samrat with Mercator

Location: Offshore-Mumbai High

Oil and natural Gas Corporation limited (ONGC) intends to develop the WO-16 cluster field located in the Mumbai High Field, 140-145km West Mumbai. As part of the WO-16 development, ONGC intends to convert the Jack up Drilling Rig Sagar Samrat to a Mobile Offshore Production Unit (MOPU). The converted MOPU will be equipped with facilities consisting of oil, gas and water separation, gas dehydration and compression, chemical injection, flare system, utilities and accommodation. The MOPU will be located adjacent the WO-16 Well Head Platform (WHP) in 76m water depth, where it will receive and process well fluids from WO-16 for an initial period of 6 years, beginning in 2015. Following processing of well fluids at the MOPU, the associated free gas will be compressed for export via the WO-16 WHP. Produced oil will also be exported from the MOPU via the WO-16 WHP.

The development of this field requires conversion of the existing Jackup Drilling Rig Sagar Samrat to a Mobile Offshore Production Unit (MOPU). It is located adjacent to the ONGC’s existingWO-16 Well Head Platform (WHP) in 76m water depth. The converted MOPU is equipped with facilities like oil, gas and water separation, gas dehydration and compression, chemical injection, flare system, utilities and accommodation. For initial 6 years, well fluids fromWO-16 will be transferred to MOPU for processing. The produced oil and associated gas after compression from MOPU is exported via WO-16WHP.

Well fluid from the WO-16 cluster is collected in the production header and combined with condensed liquids from the export gas compression trains prior to the two stage separation. The first stage separator is designed as a two-phase separator only, providing bulk vapor-liquid separation. Oil and water from the inlet separation will be let down and routed to the three-phase separator for oil recovery. The gas from the inlet separator is recovered and compressed by two parallel trains each having three stages of compression. And the gas from three phase separator is compressed by offgas compressor and recompressed via export gas compression train after mixing with gas from inlet separator. In between second and third stage of compression, TEG will be used to dehydrate the gas to mitigate pipeline corrosion. TEG is preferred at this location because second stage provides sufficient pressure to minimize water load on the unit and also reduces the absorption of carbon dioxide into TEG stream.

The associated gas after compression and the processed oil from the three-phase separator will be exported without stabilization via pipeline to WO-16 WHP. While only minimal amounts of produced water are expected, any water that is removed in the three-phase separator will be passed to the treated water dump caission for further treatment and discharge to the environment.