Networked InField Compression for CSG field development

Abstract

Driven by the LNG feed gas volume demand, recent large CSG field development in Queensland has been developed around large centralised compressor stations, designed and constructed on conventional gas project guidelines. Experience in the United States and Canada during more than four decades, however, has shown the best CSG reservoir performances and lifecycle costs are achieved with low capital cost, flexible infrastructure, and infield compression close to well heads. The Networked InField Compression System offers CSG producers significant advantages compared with centralised systems. The model comprises a grid network of well heads; low, intermediate, and high pressure pipelines; integral infield compressors, and booster compression stations. The model differs from traditional models in a number of ways. The majority of wellhead infrastructure and compression is relocated back in the field, reducing costs and inspection requirements. Low horsepower integral infield compressors are gas driven, pipeline losses are reduced and use 30–40 % less BHP than screw compressors, and skid-mounted for simple and cost-effective relocation. Coiled high pressure, low diameter flexible piping is used, which requires a narrow right of way, few connections, and can be ploughed in multiple lines from up to 5–8 km per day, depending on soil conditions.In addition to 30-40 % improvements in capital expenditure and installation time, the Networked InField Compression model offers 20–30 % lower operating costs and 10–20 % more gas from increased flow levels and/or extended well life. Further, environmental impact is decreased by 20–40%, as land use, CO2 emissions; crew sizes and peak water flow are significantly reduced compared with centralised systems.