Journal of Petroleum & Environmental Biotechnology

Kerogen: Classification and origin - A case study

4^th International Conference on Petroleum Engineering

August 15-17, 2016 London, UK

Yousif M Makeen and Wan Hasiah Abdullah

University of Malaya, Malaysia

Posters & Accepted Abstracts: J Pet Environ Biotechnol

Abstract:

The kerogen type has been classified according to hydrogen index (HI) values and hydrocarbon pyrolysis yields (S2). Type I and Type II kerogen commonly possess HI values more than 300 mg HC/g TOC and may be of either lacustrine or marine origin. Moreover, Type I and Type II kerogen have high pyrolysis yields (S2) (>15 mg HC/g rock), whereas Type III kerogens have moderate low pyrolysis yields (S2) (<10 mg HC/g rock). However, the Rock-Eval or Source-Rock-Analyzer (SRA) data (i.e. HI, OI and S2) does not always accurately represent the types of kerogen present and the types of hydrocarbon that may be generated by the source rocks. This is because mineral matrix within the source rock will influence the Rock-Eval kerogen/ SRA typing result. In addition, sediments with TOC contents of less than 2.0% can result in a significant reduction in the HI. Thermal decomposition of carbonate minerals during the Rock-Eval analysis /SRA can contribute carbon dioxide and increase the oxygenation index (OI) in low TOC sediments. On the other hand the Py-GC analysis can provides us information regarding the quantitative chemistry of the thermal decomposition products of the kerogen. This gives a direct indicator of the kerogen type and types of hydrocarbons that can be generated by the kerogen during the maturation process. Therefore, the application of Rock-Eval kerogen/ SRA techniques can provide more accurate assessments of kerogen type when used in conjunction with pyrolysise gas chromatography (Py-GC) data. The Abu Gabra Formation has clearly been established as a lacustrine deposit. But, the analyzed Abu Gabra samples are plot in the mature zone of Types I and II kerogen to mixed Type II-III kerogens (based on SRA technique). However, pyrolysis GC analysis proved that all the investigated Abu Gabra samples contain homogeneous Type I kerogen that produces mainly waxy oil. This is supported by the abundant liptinitic materials and high atomic hydrogen-to-carbon (H/C) ratio.

Biography :

Email: makeen.geo@hotmail.com