Hydrocarbon potential of the Karapinaryaylasi Formation(Paleocene-Eocene)source rock in the Tuz Golu Basin,central Anatolia,Turkey

摘要

In the Tuz Golii Basin(central Anatolia),the Karapinaryaylasi Formation(Paleocene-Eocene)is represented by shale and sandstone alternation,conglomerates and lensoid limestones.The total organic carbon(TOC)results from most outcrops and the Karapinar-2A well samples show less than 0.50 wt%,and the hydrogen index(HI)and genetic potential values are very low.In the Aktas-1A,Aksaray-1 and Sultanhani-1 wells,the TOC content is generally lower than 0.5 wt% but can reach up to 1.50wt%.Rock-Eval pyrolysis indicates that some intervals within the Karapinaryaylasi Formation possess good gas potential,with a total yield of up to 4268 ppm.The Paleocene-Eocene rocks are thermally immature to marginally mature with respect to T_(max),ranging from 420 deg C to 458 deg C,while vitrinite reflectance and spore colour index values range from 0.50% R_o to 0.88% R_o and 4 to 8(?),respectively.Microscopic investigations and the HI vs.oxygen index(OI)and HI vs.T_(max)diagrams show that the samples contain Type III and Type II kerogen,which is often oxidized,together with reworked material.Gas chroma-tography and gas chromatography-mass spectrometry analysis results support these conclusions.Consideration of all the data indicates that the Karapinaryaylasi Formation(Paleocene-Eocene)could be the source rock for gas production in the Tuz Golii Basin.