Author(s)

Temesgen Oljira^1*, Matthew E. Nton², Oluwadayo O. Sonibare³

¹Pan African University Institute of Life and Earth Science (Including Health and Agriculture), University of Ibadan, Ibadan, Nigeria.
²Department of Geology, University of Ibadan, Ibadan, Nigeria.
³Department of Chemistry, University of Ibadan, Ibadan, Nigeria.

Shale sample from Bokh Formation, Ogaden basin, Ethiopia was assessed for their petroleum potential by Rock-Eval pyrolysis. The Total Organic Carbon (TOC) values range from 0.76 to 0.86 wt%. These values exceed the minimum value of 0.5 wt% required for potential petroleum source rocks. The genetic potential (GP) and hydrogen index (HI) values range from 0.09 to 0.5 mg/g and 8 - 32 mgHC/gTOC, respectively. These values are generally lower than the minimal 2 mg/g GP and 200 mgHC/g HI required for a potential source rock. Several plots from the Rock-Eval pyrolysis data classify the samples as type IV kerogen with no potential to generate hydrocarbons. The Tmax and Production Index (PI) values range from 388°C to 453°C and 0.28 to 0.46, respectively. These values indicate that the shales are thermally matured. These results show that the shales from the Bokh Formation in Ogaden basin have no potential to generate hydrocarbons mainly crude oil, but are thermally matured and may generate natural gas.

Ogaden Basin, Bokh Formation, Shale, Hydrocarbon, Source Rock

Oljira, T. , Nton, M. and Sonibare, O. (2020) Organic Geochemical Evaluation of Shale Units of Bokh Formation, Ogaden Basin, Ethiopia. Open Journal of Geology, 10, 565-578. doi: 10.4236/ojg.2020.105025.