Geochemical Source Rocks Evaluation and Hydrocarbons Studies in North of Dezful Embayment

Abstract

In the context of this evaluation, the most relevant ones are the Lower Cretaceous Garau, and Middle to Upper Cretaceous Kazhdumi and Gurpi Formations and the Tertiary Pabdeh. The potential source rocks investigated include the Pabdeh, Kazhdumi and Garau Formations. These three formations, which are important source rocks in the basin and have been discussed extensively in the literature, were used as a laboratory standard in this study. The crude oils examined in this study were obtained from reservoir formations of various ages from throughout the area. The source rock screening analysis indicates that the Garau and Kazhdumi especially from the Northwestern part of the area, and Pabdeh in the southeastern part have substantial oil-generation potential. The Gurpi is not a source rock, although has mostly black shales. Selected source rock and oil samples were characterized in more detail, and the distributions and concentrations (both relative and absolute concentrations) of biomarkers in different source rocks and oils were determined. The biomarker characteristics were combined with other geochemical and geological data to interpret the sources, depositional environments, lithology and maturity. Oil–source rock correlations were made between source rocks and a number of crude oils based on quantitative and qualitative biomarker distributions.