Page 312 - Introduction to Petroleum Engineering

SAKHALIN‐2 PROJECT, SAKHALIN ISLAND, RUSSIA 301
TAblE 15.2 Typical Composition of Natural gas Products
Number of Natural Residential
Component C Atoms Gas LNG Gas LPG NGL
Methane 1 X X X
Ethane 2 X X X X
Propane 3 X X X X
Butanes 4 X X X
Pentanes 5 X X
Natural gasoline 5+ X X
Nonhydrocarbon gases X
(CO , H O, H S, N , etc.)
2
2
2
2
Water X
TAblE 15.3 Typical Recovery of Components at Different Ngl Plants
Component “Lean Oil” (%) Refrigeration (%) Cryogenic (%)
Ethane 15–30 80–85 85–90
Propane 65–75 100 100
Butane and isobutane 99 100 100
Pentanes 99 100 100
Natural gasoline 99 100 100

its normal boiling point of −259°F (−162°C). At its destination, LNG is vaporized
and heated to appropriate temperature for pipeline transport to industrial and residen-
tial markets.
LPG consists mostly of propane or butane or mixtures of the two. LPGs are often
used as transportation fuel and as heating fuel in remote locations. LPG must be
transported or stored in pressure vessels. Depending on composition, the required
pressure varies from about 40 psi to almost 200 psi at ambient temperatures.
Processing plant technology determines the quality of natural gas liquids (NGL)
recovered from the input gas stream. Table 15.3 shows the typical recoveries of gas
components at different NGL plants. A “lean oil” plant recovers 99% of butanes and
components with five or more carbons but is less efficient at recovering lower molec-
ular weight components (ethane and propane). Refrigeration plants use propane to
cool the input gas and recover more of the lower molecular weight components.
A cryogenic plant is a very low‐temperature facility and recovers more ethane than
the refrigeration plant.

15.4 SAKHAlIN‐2 PROJECT, SAKHAlIN ISlAND, RuSSIA

The Sakhalin‐2 project is operated by Sakhalin Energy and is dedicated to developing
two world‐class offshore fields: Lunskoye and Piltun‐Astokhskoye (P‐A). The infra-
structure for Sakhalin‐2 has largely been built in the twenty‐first century. An