ارزيابي توان هيدروكربورزايي و شرايط رسوبگذاري سازند در ميدان نفتي مسجد سليمان

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

Sargelu Formation is deeply buried and has limited distribution in Dezfiil 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 Dezfiil 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-Eva! VI pyrolystsand 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, T_ 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 I] and III. In all, the organic matter in well No. 316 has a better Kerogen type (mixed type II and Ifl). All die Samples plotted on Smith Diagram have more than 0.1 S^OC ratios and capable ofgenerating hydrocarbon. The Pr/nCJ7 vs. Ph/nC|S ratio demonstrates marine environment for Sargelu Formation. Pyro and thermograms reveal that normal alkanes are dominated in Cl5 — CJ0 range, whiJe 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 paleoenvironmenf 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.