ENERFLEX SYSTEMS LTD. ANNUAL INFORMATION FORM For the ...

ENERFLEX SYSTEMS LTD. – ANNUAL INFORMATION FORM
The following section provides an overview of the compression, production and processing, and
power markets and applications.
Compression
Natural gas, including coal-bed methane gas, (together “natural gas”) is found in underground reservoirs and coal
seams. The pressure of the gas at the wellhead is generally too low to enable it to be transported to its destination
for consumption. Virtually every cubic foot of natural gas requires compression at some point in the transportation
and processing cycles. Compression equipment is used to increase the pressure within gas gathering systems and
processing plants. Generally several compressors are required to sustain the pressure necessary to deliver gas
from a typical field to the main line high pressure transmission facility and to its end use.
Demand for compression occurs when new wells are drilled or when reservoir pressures decline in existing fields. A
combination of additional compression and development drilling is invariably required to offset the decline in
reservoir pressures. This is particularly evident in shallow gas reservoirs and coal-bed methane gas fields, where
production can be brought on quickly and with relatively low capital costs, but will usually experience low initial
production pressure or rapid production declines.
Enerflex packages and services reciprocating and screw type compressors. A typical compressor package consists
of a steel or concrete skid, gas compressor, driver such as a reciprocating engine, gas turbine or electric motor, gas
cooler, liquid or particulate separation, piping and a control system. In colder climates the equipment is enclosed in
an insulated building.
Compression is required both in land and offshore applications. The following are some of the more common
compression applications:
Land Based Applications
• Wellhead Compression – Compression at or near the wellhead is almost always required to boost the pressure
of produced gas to slightly more than the pressure in the transmission pipeline.
• Gas Gathering – Mid to large horsepower (“HP”) compressors (800 to 6,000 HP) deployed at a central field
location, are used to boost gas pressure from several wells.
• Gas Storage and Withdrawal – Natural gas is often stored in underground facilities such as depleted oil or gas
reservoirs or salt caverns. This is done to balance production with seasonal demand. Compression is required
both to inject gas into the storage reservoir and to subsequently withdraw the gas for reinjection into the
pipeline. Storage facilities typically use compressors in increments of 2,000 to 3,000 HP.
• Coal-Bed Methane – Methane trapped in coal-beds or seams occurs naturally at low pressures. Its production
requires a combination of reciprocating and screw compression near the wellhead.
• Fuel Gas Boosting – Most large gas turbine power generation plants require compressors to boost the fuel gas
pressure from the low (30 PSI) pressure delivered by the local utility, up to the much higher pressures (350 –
650 PSI) required by the turbine. These units typically are driven by electric motors. Their control systems are
highly sophisticated to regulate a proper flow of fuel while the turbine undergoes load changes.
• Gas Lift – Compressors are used to increase oil production by injecting gas into the oil reservoir. This increases
reservoir pressure and facilitates the oil flow. At the surface, the gas is separated from the oil, recompressed
and then re-injected in a continuous cycle. Local conservation and environmental regulations often make reinjection
mandatory.
• Enhanced Oil Recovery (EOR) – This process involves the injection of carbon dioxide or other gases by means
of compression. Operators use EOR to decrease the viscosity of oil to enable it to flow from the reservoir
formation.
• Gas Processing – Gas plants typically require mid to large HP compressors for processing and boosting the
pressure between inlet and outlet supply pipelines.
Offshore Applications
Compression equipment is used on FPSO (Floating Production, Storage & Offloading) vessels and other offshore
units to re-inject gas associated with oil production back into the reservoir. Most offshore operating regulations
prohibit the flaring of gas. Re-injection may also be necessary to increase production, or where pipeline access is
unavailable or uneconomic. Reciprocating compression equipment is gaining market acceptance for offshore gas
re-injection projects where the gas volumes are generally lower and the required differential pressures are high.
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