Source rock and shale oil potential of the Pabdeh Formation (Middle–Late Eocene) in the Dezful Embayment, southwest Iran
Keywords:Pabdeh BSU, Organic matter, Biomarkers, Mineral composition, Oil potential.
The Pabdeh Brown Shale Unit (BSU) is an organic-rich calcareous mudstone within the Paleogene Pabdeh Formation, which has not yet been investigated in detail. A total of 166 core and cutting samples were selected from four wells in the Dezful Embayment to investigate the organic geochemical and the mineralogical compositions, as well as the shale oil potential of the BSU. XRD results show that it is mainly comprised of calcite (53wt.%), clay minerals (25wt.%), and quartz (14wt.%). TOC contents generally range from 1 to 9wt.% (avg. 4.2, 2.9, 5.2 and 3.3wt.%, for GS, KR, RR and RS wells, respectively) with HI values ranging between 400 and 650 mg HC/g TOC. Based on average values of Tmax and vitrinite reflectance, as well as saturate biomarker ratios, the BSU is immature at wells RR and RS (ranging from 0.3 to 0.53%) and its maturity increases northward at wells KR and GS (ranging from 0.5% to 0.67%). The organic matter is dominated by Type ΙΙ kerogen and is generally composed of liptinite and amorphous material with minor terrestrial input. Based on various biomarker parameters, the organic matter was most likely deposited under anoxic marine conditions. The mineralogical characteristics (i.e. presence of brittle minerals) and organic geochemical properties (i.e. TOC >2wt% and Type II kerogen) support the conclusion that the Pabdeh BSU displays a considerable shale oil potential where it attains appropriate thermal maturity.
The commercial rights of the printed and online versions of Geologica Acta are property of the UB, ICTJA, IDAEA and UAB, and Geologica Acta must be cited for any partial or full reproduction.
The opinions and conclusions stated in each article are the exclusive responsability of the authors and do not necessarily coincide with those of the above mentioned institutions UB, ICTJA, IDAEA and UAB.
Authors retain the copyright on their papers (accepted manuscript, uncorrected proof and published paper) and are authorized to post them on their own Web page or their institutional repositories. In all cases, the complete citation and a link to the Digital Object Identifier (DOI) of the article must be included.
The authors can use excerpts or reproduce illustrations of their papers in other works without prior permission of Geologica Acta provided the source of the paper including the complete citation is fully acknowledged.
Papers are distributed under the Attribution-Share Alike Creative Commons License. This license allows others to alter, remix or build upon a paper and the resulting work may be distributed under the same or similar license to this one.