The Onshore Processing Facility (OPF) is located in the north-eastern part of Sakhalin Island, near the landfall of the marine gas pipeline from the Lunskoye Platform. The facility houses processing equipment, Booster Station 1, and the Compression Facility (OPFC), brought into operation in 2023 as part of the Sakhalin-2 Project development. The OPF occupies an area of 62 hectares, excluding the territory allocated for the OPFC.
The OPF is designed for the treatment of gas and condensate produced from the Lunskoye field. The process equipment includes gas processing and compression and condensate stabilisation units.
The OPF is fully autonomous and has all facilities required for efficient operation, including power generation for its own needs and for the LUN-A platform. Power is generated by four 25 MW gas turbines. In addition, the OPF feeds the LUN-A platform with monoethylene glycol (MEG), which is used to prevent hydrate formation in water-wet production fluids. Another important objective of the facility is to supply electricity and MEG to the LUN-A platform.
The OPF daily design capacity is 50.1 MMcm of gas and over 7.2 Kt of condensate.
The OPFC adjoins the existing OPF site from the east.
The key role of the OPFC is to compensate for the decline in reservoir pressure at gas production wellheads resulting from the transition of the Lunskoye field to a mature stage of development. Along with pressure declines at the Lunskoye field and a subsequent pressure decrease in the OPF multiphase inlet pipeline, there is a need to maintain design conditions for the entire OPF process system, where the inlet pressure should be 82-83 bar.
Three gas compression trains, each consisting of a gas compressor unit and a group of air coolers, have been constructed within the 21-hectare site of the OPF.
The maximum daily OPFC capacity is 56.6 MMcm/d (winter) and 49.4 MMcm/d (summer).
Booster Station 1 (BS 1) produces a specific oil-gas-condensate mixture consisting of stabilised condensate and processed oil from the PA-A and PA-B offshore platforms. This is also where the gas streams from the above-mentioned sources are combined.
The main function of BS 1 is to provide the necessary pressure to successfully transport Sakhalin Blend and gas to the Prigorodnoye Asset. This involves the use of mainline pumps, compressor units, and auxiliary equipment.
The design daily hydrocarbon export capacity of BS 1 is 51.6 MMcm of gas and more than 18K tonnes of oil-condensate mixture.