Discovery of tar mats in terrestrial gas-condensate reservoirs and its geological significance

摘要

TAR mat is reservoir zone containing petroleum rich in asphaltene, and is situated in gas-condensate reservoirs and light oil reservoirs. Tar mat is an organic barrier for oil and gas reservoirs. Recently, determination oi tar mat has become reality as thin layer chromato-graphy-flame ionization detection(TLC-FID) technique is applied to organic geochemical description for petroleum reservoirs. The geochemical characteristics and formation mechanisms of tar mat originating from marine source rocks have been reported, while the report of tar mat originating from terrestrial source rocks is rarely seen. By studying reservoir geochemistry of Tarim Basin, the author found two layers of tar mats in terrestrial gas-con-densate sandstone reservoirs in Yahafield. In this note, geochemical indications for determination of tar mat in terrestrial gas-condensate sandstone reservoirs will be established.