Determining Source Rock and its Characteristics Using Organic Geo-Chemistry Derived from Parent Rock Evaluation, Separation, and Columnar and Gaseous Chromatography on Cretaceous Units in Central Iran at Khor-Biyabanak

Abstract

Recently, the investigations made on rocks of cretaceous units at Central Iran have revealed source rocks and their characteristics (origin, amount, and type, maturation of organic material, hydrocarbure (Hydrocarbon) generation ability and sedimentary organic material environment). The information obtained from investigation and evaluation of cretaceous rock units at Khor-Biyabanak region using following methods have led to the determination of the source rocks with some weak to medium organic material from the downstream to upstream of the section (underlying-intermediate cretaceous towards upstream cretaceous) in the region such as evaluation of source rock, separation of Bitumen, columnar Chromatography, and aseous Chromatography. With due regard to the amounts of TOC, HI, Tmax, S1, S2, PI, EOM, HCS, SAT/ARO, CPI, Pr/Ph, pr/n-c17, ph/n-c18, and the ratios, graphs, and derived peak values, it can be claimed that the type of organic materials present in the source rocks are Classes II and III Kerogens. The maturation of existing organic material in the source rocks is high and shows approximately the ending oil generation window and last stages of Catagenesis (Katagenesis). The origin of the organic material is also a marine and continental mixture which currently is capable to generate humid and dry gas in the existing source rocks. Also, the formation environment of existing source rocks is regenerative, and quasi-regenerative-marine.