Scientific Quarterly Journal of Geosciences

Scientific Quarterly Journal of Geosciences

Hydrocarbon Potential Evaluation and Depositional Environment of Sargelu Formation in Masjid-i-Soleiman Oilfield

Document Type : Original Research Paper

Authors
B. Alizadeh
S. H. Hosseini
Department of Geology, Earth Science Faculty, Shahid Chamran University, Ahwaz, Iran
10.22071/gsj.2010.55468
Abstract
Sargelu Formation is deeply buried and has limited distribution in Dezful Embayment (limited to the northern part), hence, investigation of petroleum potential of this formation has attracted many petroleum geologists. In this study, hydrocarbon potential of Sargelu Formation in Northern Dezful Embayment is evaluated geochemically. For this purpose 34 drill cuttings from well numbers, 309, 310, 312 and 316 in Masjid-i-Soleiman (MIS) oilfield were selected, and geochemical analyses such as Rock-Eval VI pyrolysis and PY-GC were performed. The results reveal that the formation has “Very Good” hydrocarbon potential because of its high amounts of Total Organic Carbon (TOC). Results were plotted on Van-Krevelen as well as on HI vs. Tmax diagrams, and demonstrated mixed Kerogen Type III and IV due to low HI caused by higher thermal maturity, in well numbers 309, 310 and 312. However, the prominent Kerogen type was determined to be of mixed Kerogen type II and III. In all, the organic matter in well No. 316 has a better Kerogen type (mixed type II and III). All the Samples plotted on Smith Diagram have more than 0.1 S1/TOC ratios and capable of generating hydrocarbon. The Pr/nC17 vs. Ph/nC18 ratio demonstrates marine environment for Sargelu Formation. Pyro and thermograms reveal that normal alkanes are dominated in C15 – C20 range, while heavy normal alkanes are missing due to its high thermal maturity. In all it can be concluded that Sargelu Formation in MIS oilfield, due to its paleoenvironment as well as burial depth exclusively has a good quality of organic matter with adequate maturity at the end of oil window and hence is gas-prone.
Keywords
Dezful embayment
Masjid-i-Soleiman Oilfield
Sargelu Formation
Genetic Potential
Depositional environment
Rock-Eval
Pyrolysis– Gas Chromatography
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Scientific Quarterly Journal of Geosciences
Volume 19, Issue 75
Winter 2010
Pages 173-178