7 FIELDS Natural Gas Underground Storage Facility in Austria - 1st stage of expansion completed
On 31 March 2011, Chemieanlagenbau Chemnitz GmbH (CAC) completed the 1st stage of expansion of 7 FIELDS underground storage facility for the consortium of RAG / E.ON Gas Storage.
The 1st stage of expansion includes the underground storage facilities Zagling and Nussdorf. They have a working gas volume of altogether 1,155 million Nm³ and enable the development of three natural gas fields.
Each of the plants can be operated separately or together with the other stations and consists, in addition to the probes, mainly of compressor units, gas drying units as well as all required gas treatment units and off-sites.
A great deal of attention was paid to gas compression, where for the first time two-stage gas compressors of type ICL with magnetic bearings are commercially used in an natural gas stor-age facility. Depending upon the existing pressure and throughput conditions, the compressor stages can be operated in parallel or serial mode. With regard to gas drying, preference was given to the adsorption process, to ensure adjust-ment of the water dew point and also of the dew point of hydrocarbons.