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
seismic faults.
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