Determination of Total Organic Carbon (TOC) Content and Investigating Oil Generation of Pabdeh Formation in Ahwaz and Marun Oil Fields Applying ΔlogR Method

Document Type : Research Paper

Authors

1 Geology Department, National Iranian South Oil Company (NISOC), Ahvaz

2 Petroleum University of Technology

Abstract

Well logging tools are one of the most useful methods for formation evaluation in a sedimentary basin. Therefore, well log data could be used as an indicator for determination of source rock potential. Characterizations of Kazhdomi, Pabdeh and Gurpi source rocks have been determined by geochemical analyses in some of Iranian oil fields, but no TOC zonation and interpretation have been carried out in these formations yet. The aim of this study is to estimate the TOC content by means of combination of sonic and resistivity logs (ΔlogR method), which were run in Pabdeh and neural network method and then compare with TOC results from geochemical analysis (Rock-Eval VI) in Ahwaz and Marun oil fields. Consequently, the results led to zonation of TOC in mentioned oil fields. Also, the intervals which Pabdeh formation has reached to oil generation window were determined with respect to TOC rich zone thickness changes and geothermal gradient of wells.

Keywords


منابع
[1] Hunt J.M., Petroleum Geochemistry and Geology, 2nd ed. W.H. Freeman and Company (Eds), New York, 1996.
[2] Tissot B.P. & Welte D.H., Petroleum Formation and Occurrence, Springer-Verlag, New York. 966 p, 1984.
[3] Serra O., “Fundamentals of Well-Log Interpretation”, The Acquisition Logging Data vol. 1.Elsevier. 679 p, 1986.
[4] Beers R.F., “Radioactivity and organic content of some Paleozoic shales,” AAPG Bulletin Vol. 26, pp. 1–22, 1945.
[5] Schmoker J.W., “Determination of organic matter content of Appalachian Devonian shales from gamma-ray logs”, AAPG Bulletin Vol. 65, pp. 2165–2174, 1981.
[6] Fertle H., “Total organic carbon content determined from well logs”, SPE Formation Evaluation 15612, pp. 407 – 419, 1988.
[7] Hertzog R., Colson L., Seeman B., O’Brian M. & Scott H., “Geochemical logging with spectrometry tools”, SPE Formation Evaluation Vol. 4, pp. 153–162, 1989.
[8] Meyer B.L. & Nederlof M.H., “Identification of source rocks on wireline logs by density/resistivity and sonic transit time/ resistivity cross plots”, AAPG Bulletin Vol. 68, pp. 121 – 129, 1984.
[9] Passey O.R., Moretti F.U. & Stroud J.D., “A practical modal for organic richness from porosity and resistivity logs”, AAPG Bulletin 74, pp. 1777 – 1794, 1990.
[10] Sherkati Sh. & Letouzey J., “Variation of structural style and basin evolution in the central Zagros (Izeh zone and Dezful Embayment)”, Iran. Marine and Petroleum Geology Vol. 21, pp. 535-554, 2004.
[11] Mccord, Regional Geology of Asmari reservoir in Ahwaz-Marun area, Technical reports in NISOC, Iran, 1974.