MAXIMISING
FLOWRATE WHILE
MINIMISING
PRESSURE LOSSES
Low ratio compressor application
for pipeline stations:
Prashant
Gijavanekar, P.E. and Jack Smith,
SNC-Lavalin, USA,
discuss the design
to maximise flow.
F
or many years, low pressure ratio compression applications
were designed with a relatively narrow operating range. The
compressors operated fairly close to the design conditions
at the driver-rated speed and power to achieve maximum
throughput. This allowed for standardisation in the compressor
design and easier selection of the compressor components.
Today, development of the shale resources has changed the
way compressors are designed and operated. It is now commonly
expected for the compressors to operate over a wide operating
range. A flexible design approach is required to meet the
variable or declining well pressure (production) profiles. Current
economics also dictate that the compressor flowrate be maximised
throughout the entire operating range to improve profitability.
Designing a wide operating range compressor presents a unique
set of challenges. Traditionally, the pressure pulsations generated
by the compressor are controlled by utilising large pressure
vessels and restriction orifice plates in the pipeline. Installing large
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