Until recently it has been a common practice in oil fields to flare associated petroleum gas resulting from the initial treatment of crude oil prior to transportation by pipeline.
In accordance with Russian regulations 95% of associated petroleum gas must be processed before 2011. For this purpose the gas has to be compressed. Working discharge pressures of the compressors installed in oil fields are generally within 20 to 50 bar. Alternative gas engine-driven compressors are typically employed for this purpose. The typical power rating of a single compressor set is 22 to 1000 kW. Compressor drive is usually fueled by the transported gas. In some cases associated petroleum gas may contain hydrogen sulfide, and sometimes its content may be quite significant (up to 6%). This requires a special configuration of gas flow path in the compressor and the drive.