Biomarkers geochemistry of the Alpagut oil shale sequence: an evaluation of dispositional environments and source rock potential from Dodurga-corum basin (N-Turkey)

KORKMAZ S., KARA GÜLBAY R., Khoitiyn T., ERDOĞAN M.

JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY, cilt.12, sa.8, ss.2173-2189, 2022 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 12 Sayı: 8
  • Basım Tarihi: 2022
  • Doi Numarası: 10.1007/s13202-021-01450-5
  • Dergi Adı: JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, ABI/INFORM, Aerospace Database, Aquatic Science & Fisheries Abstracts (ASFA), Communication Abstracts, Compendex, Metadex, Directory of Open Access Journals, Civil Engineering Abstracts
  • Sayfa Sayıları: ss.2173-2189
  • Anahtar Kelimeler: cankiri-corum basin, Oil shale, Biomarkers, Depositional environment, Hydrocarbon potential, DEPOSITIONAL ENVIRONMENT, AROMATIC-HYDROCARBONS, CENTRAL ANATOLIA, CRUDE OILS, MATURATION, MATURITY, PETROLEUM, MIOCENE, DIBENZOTHIOPHENES, DISTRIBUTIONS
  • Karadeniz Teknik Üniversitesi Adresli: Evet

Özet

The Cenozoic cankiri-corum basin, with sedimentary facies of varying thickness and distribution, contains raw matters such as coal deposits, oil shales and evaporate. Source rock and sedimentary environment characteristics of the oil shale sequence have been evaluated. The studied oil shales have high organic matter content (from 2.97 to 15.14%) and show excellent source rock characteristics. Oil shales are represented by very high hydrogen index (532-892 mg HC/g TOC) and low oxygen index (8-44 mgCO(2)/g TOC) values. Pyrolysis data indicate that oil shales contain predominantly Type I and little Type II kerogen. The biomarker data reveal the presence of algal, bacterial organic matter and terrestrial organic matter with high lipid content. These findings show that organic matters in the oil shales can generate hydrocarbon, especially oil. High C-26/C-25, C-24/C-23 and low C-22/C-21 tricyclic terpane, C31R/C-30 hopane and DBT/P ratios indicate that the studied oil shales were deposited in a lacustrine environment, and very low Pr/Ph ratio is indicative of anoxic character for the depositional environment. T-max values from the pyrolysis analysis are in the range of 418-443 degrees C, and production index ranges from 0.01 to 0.08. On the gas chromatography, high Pr/nC(17) and Ph/nC(18) ratios and CPI values significantly exceeding 1 were determined. Very low 22S/(22S + 22R) homohopane, 20S/(20S + 20R) sterane, diasterane/sterane and Ts/(Ts + Tm) ratios were calculated from the biomarker data. Results of all these analyses indicate that Alpagut oil shales have not yet matured and have not entered the oil generation window.