Petroleum source rock potential of the Silurian Dadaş shales in the Hazro and Korudağ regions of Southeast Anatolia, Turkey

• Published in: Marine and petroleum geology Vol. 75; pp. 53 - 67
• Main Authors: Öztürk, S.S., Demirel, İ.H., Günay, Y.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2016
• Subjects: Dadaş Formation; Illite crystallinity; Shale oil and gas potential; Silurian; Source rock quality; Southeast Anatolia; Thermal maturity; Turkey; Silurian; Turkey; Southeast Anatolia; Source rock quality; Thermal maturity; Shale oil and gas potential; Dadaş Formation; Illite crystallinity
• ISSN: 0264-8172; 1873-4073
• DOI: 10.1016/j.marpetgeo.2016.04.007

Shales of the Silurian Dadaş Formation exposed in the southeast Anatolia were investigated by organic geochemical methods. The TOC contents range from 0.24 to 1.48 wt% for the Hazro samples and 0.19 to 3.58 wt% for the Korudağ samples. Tmax values between 438 and 440 °C in the Hazro samples indicate thermal maturity; Tmax values ranging from 456 to 541 °C in the Korudağ samples indicate late to over-maturity. Based on the calculated vitrinite reflectance and measured vitrinite equivalent reflectance values, the Korudağ samples have a maximum of 1.91%R(g-v), in the gas generation window, while a maximum value of 0.79%R(amor-v) of one sample from the Hazro section is in the oil generation window. Illite crystallinity (IC) values of all samples are consistent with maturity results. Pr/Ph ratios ranging from 1.32 to 2.28 and C29/C30 hopane ratios > 1.0 indicate an anoxic to sub-oxic marine-carbonate depositional environment. The Hazro shales do not have any shale oil or shale gas potential because of their low oil saturation index values and early to moderate thermal maturation. At first glance, the Korudağ shales can be considered a shale gas formation because of their organic richness, thickness and thermal over-maturity. However, the low silica content and brittle index values of these shales are preventing their suitability as shale gas resource systems. •The Silurian Dadaş shales have been investigated in Hazro and Korudağ areas.•Organic matter in Silurian shales was originated from marine organisms.•Illite crystallinity values correspond to “high diagenetic zone”.•The Pristane/Phytane ratios indicate an anoxic and sub-oxic depositional environment.•Clay and mica minerals predominate in the Silurian shales.