Determination of Non-Related Residual Oil (Bitumen) Present in Kangan Formation with Gas and Condensate in this Reservoir (South Pars Field)

Silurian shales (Sarchahan Formation), with high volume of organic matter, are the major source rock of Dehram Group reservoir in South Pars Gas Field.Residual oil (bitumen) were seen on some parts of Kangan Formation core. According to some reports, Lower Triassic (Kangan Formation) sediments is a possible source rock, for Kangan reservoir contents (gas and condensate). Recent geochemical study on tar and asphaltic oil of Kangan Formation (not reservoir contents), shows that these oily materials were produced from shaly and shaly- limestone layers of Kangan Formation, but due to low TOC content, poor source rock potential, and low maturity level (late diagenesis) of Kangan, this Formation is incapable of production of huge amount of gas and condensate. It seems that the produced hydrocarbons from shaly and limestone layers of Kangan Formatin, has no relation with hydrocarbons generated from Silurian shales.