Gas compression systems are an essential component of gas production, processing and transmission facilities, and have a significant influence on overall capital and operational costs. Compression equipment is also a major contributor to downtime and production loss. The proper specification and selection of compression equipment can therefore greatly improve economic feasibility.
In many cases, there are multiple operating conditions to consider and often uncertainty over long-term requirements. Poor choices, or failure to consider full lifecycle requirements, can lead to machinery that is not suited to eventual operating conditions, whether operating inefficiently, being a production bottleneck, or introducing excessive maintenance requirements.
New compression technologies continue to come to market. Improvements in large high speed motors, active magnetic bearings and variable frequency drives, have led to the availability of low maintenance oil free compression, without the need for gearboxes and journal bearings. On top of this, a number of manufacturers have solutions for the integration of the motor within the compressor casing, eliminating all rotating seals. New ground is also being broken in the development of machines capable of delivering high compression ratios, which could lead to more compact equipment. A drive to reduce atmospheric emissions has led to advances in the combustion technology in gas turbines and engines used to power compression systems, and catalytic systems to further reduce emissions are starting to become more commonplace.
Compressor and driver types
There are several types of compressor available, commonly categorised as either positive displacement or dynamic type. There are also choices to be made on driver selection to best match compressor rotational speed and power requirements. Positive displacement type compressors tend to have lower running speed and are typically driven by gas engines or electric motors. Dynamic compressors, with their higher rotational speeds, are typically driven by steam turbines, gas turbines or electric motors.
The most common dynamic compressor used in natural gas applications is the…
Written by Michael Rimmer and Grant Johnson, Costain, UK.
Read the article online at: https://www.hydrocarbonengineering.com/special-reports/04082017/compressor-of-choice/