Transportation to the LNG Plant

Offshore fields in the north of Sakhalin are situated in the subarctic zone where the sea is covered by ice during the winter months which significantly complicates access to the facilities located there. To make exports possible throughout the year, crude oil and gas are transported to Aniva Bay in the south which remains largely ice-free during winter time.

To this end, the TransSakhalin pipeline system—a vast network of offshore and onshore pipelines running nearly through the whole island, from the north to the south—has been built. One of its main components is the Onshore Processing Facility (OPF) located in the north of the island, near Nogliki, where pipelines from the LUN-A offshore platform cross the shoreline. Pipelines from the PA-A and PA-B platforms further in the north also run via this OPF.

OPF

The Onshore Processing Facility (OPF) is a processing plant with several functions. Its primary function is the removal of impurities from hydrocarbons, separation of individual hydrocarbons and compression before introducing into the pipeline.

The OPF facility uses some of the gas to generate power for the OPF and for the LUN-A platform at a 100 MW power plant that the OPF facility includes.

The OPF can be compared to a small town in the woods, which has “houses” and “streets” and is well lighted.

When fully operational, the OPF will be capable of processing 51 mln m³ of gas per day and some 9,500 m³ of condensate/oil per day.

The TransSakhalin pipeline system

The total length of the offshore pipelines is 300 km. These pipelines are running in the areas with heavy ice conditions. The impacts of ice on underwater facilities are well known, but Russia had never before built oil and gas pipelines in ice conditions. To protect the pipelines from ice scouring, the pipelines were buried in down to 5m deep trenches near landfall.

Onshore oil and gas pipelines run from the landfall near the Piltun-Astokhskoye field via the OPF to the Prigorodnoye terminal. Each of the two pipeline strings (one for oil and one for gas) run for approximately 800 km. Booster Station No. 2 is located roughly in the middle of this route, near Gastello, to maintain the required pressure in the pipelines. It includes crude oil booster pumps, gas compressors and accessory equipment, including a nitrogen oxides suppression system.

Onshore pipelines cross 19 faults, more than 1,000 watercourses and other natural obstacles. Sakhalin Energy used the most advances methods to complete the construction of fault and river crossings. The unique design of the fault crossings allow the pipe to move within a 5-metre range. River crossings are built in a way that preserves salmon spawning grounds. Once the pipelines construction was completed, Sakhalin Energy implemented erosion control and other remediation measures.

Since Sakhalin is a seismic-hazardous area, a seismic monitoring system has been installed to provide detailed data on seismic events along the entire 800-kilometre route of the pipeline.