Abstract
In this study, Karadere oil seep (solid bitumen) and Late Cretaceous shales and carbonate levels of the Hekimhan Formation in Hekimhan Basin are compared genetically by means of organic-geochemical data. Investigated shale samples have generally low (< 0.5%) the total organic carbon values (TOC, wt%) and there is no petroleum and gas source-rock potential; however, the amount (0.11–5.92%) and type (type II–III kerogen) of organic matter within limestone are consistent for source-rock potential. On the basis of average Tmax (433 °C) and 0.53% R0 values, the investigated samples are at the immature and early mature level for hydrocarbon generation. According to biomarker data, the bitumen is pre-Cretaceous in age, highly reducing conditions, formed in a marine depositional environment at normal salinity, and under the influence of high bacterial activity, and was originate from an immature carbonate source rock. These geochemical data are highly in agreement with the late Cretaceous limestone of the Hekimhan Formation, and these rocks may be considered the source rock of the solid bitumen. However, these organic richness zones formed from non-indigenous organic material, and therefore, it is concluded that this seepage which generates from non-indigenous organic materials cannot be due to the limestone at the evaluated level. On the basis of organic-geochemical evaluations, it has been concluded that, in Hekimhan Basin, some hydrocarbons developed in deeper, more mature intervals of the limestone, and that these were migrated probably only a short distance within the basin and became really surfaced in relation to tension fractures.
Highlights
The restricted Turkey’s local energy resource, fossil fuels in light of its growing energy claim have resulted in obedience on energy imports
As it is the case in sample MH-8 in Location 1” (L-1), the extractable hydrocarbon amounts are low (217 ppm) in the samples that are poor in organic matter, and extremely higher in the limestone in the Location 2” (L-2) (13,456–91,137 ppm) (Table 1)
The limestone samples in L-2 are observed in type II–III kerogen, which is mostly close to type II, and the shale samples are observed in type III area (Fig. 4)
Summary
The restricted Turkey’s local energy resource, fossil fuels in light of its growing energy claim have resulted in obedience on energy imports. Turkey imports nearly 89% of its oil requirement (http:// www.mta.gov.tr/). Since the early periods of oil and gas exploration activities, hydrocarbon seeps (solid or liquid) have been considered as an important clue. It does not always show an oil accumulation of economic value, it has been considered as a sign that requires assessment for new exploration areas (Clarke and Cleverly 1991). Hydrocarbon seep is important in following the movement of oil that is generated by the source rocks or from underground reservoir towards surface, and for the estimation of the migration route and accumulation areas. The seeps of the hydrocarbon accumulations in bigger and continuous amounts on the sedimentations that are on the surface is defined as “Active
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of Petroleum Exploration and Production Technology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
