Oil and gas produced under the Sakhalin-2 project are
transported via the transsakhalin pipeline system. These oil and
gas pipelines run almost the length of the island and cross 19
Onshore oil and gas pipelines are running from the landfall near Piltun-Astokhskoye field in the north of Sakhalin Island via the onshore processing facility (OPF), to Prigorodnoye, in the south. The two pipeline systems (one for oil and one for gas) share a single 800 km right of way (RoW).
The distance from the Piltun-Astokhskoye landfall to the OPF is 172 km (pipeline diameters in this part of the route are 20 inch for both the oil and the gas line). The distance from the OPF to the LNG plant and OET is 637 km (pipeline diameters in this part of the route are 24 inch and 48 inch for the oil and gas line respectively). Two short multiphase pipelines (30 inch diameter, onshore length 7 km) and a 4 inch Mono-Ethelyne Glycol (MEG) pipeline in the same RoW connect the landfall at Lunskoye to the OPF.
The oil and gas pipelines share a single pipeline corridor. The pipelines are each installed in a separate trench (backfilled by a minimum 0.8-1.0 m layer of soil over the pipe). The external surface of the line pipe has an external three-layer polyethylene to protect them against external corrosion. At fault-crossing sites, special pipe-laying techniques are used to ensure their safety in case of seismic activity.
Operation of both main pipelines is controlled by a state-of-the-art pipeline leakage detection system. Six pipeline maintenance depots (PMD) and 104 block valve stations are installed along the pipeline route.
The total length of the pipeline system, including offshore pipelines, is 1,900 km, slightly shorter than the main artery of the Great Wall of China.
Transsakhalin pipeline system in wikipedia