Geochemical Characteristics and Hydrocarbon Generation Modelling of Early Triassic to Late Cretaceous Formations within Ogaden Basin, Ethiopia

Document Type : Research Paper

Authors

1 Pan African University Life and Earthscience Institute (PAULESI)

2 Department of Geology University of Ibadan Ibadan, Nigeria

3 School of Earthsciences Addis Ababa Science and Technology University Addis Ababa, Ethiopia

Abstract

The major goal of this study is the evaluation of the source rock of Ogaden Basin using Rock-Eval Pyrolysis, Vitrinite reflectance (%Ro), and well log data of the Permo-Triassic and the Mesozoic sequences including Karro, Hamanlei, and Urandab Formations. Burial history and level of thermal maturity of the Bodle-1 well, the Calub-1 well and the Hilala-2 well were modeled based on the calibration of measured %Ro and Tmax against calculated %Ro model. The calculated Total Organic Carbon (TOC) content from the well log data compared with the measured TOC from the Rock-Eval pyrolysis in the three mentioned wells is shown to match against the shale source rock.
The total organic carbon (TOC) content value ranged from 0.48 to 4.24 wt % while the S1 and S2 values ranged from 0.05 to 0.76 (mg/g) and 8.52 to 27.88 (mg/g) respectively. Hydrogen index (HI) versus oxygen index (OI) plot has shown that the organic matter is predominately made up of type III kerogen (gas prone) while Tmax and HI indicated mixed type II/III kerogen (25% of Urandab Formation, 40% of Bokh Formation and 15% of Hamanlei and Adigrat Formations). Tmax was assessed from vitrinite reflectance (Ro) readings for Bodle-1, Calub-1 and Hilala-2 wells showed an average vitrinite reflectance values in the range of 0.5-1.4 VRo%, 0.35-1.08 VRo %, 0.55 – 0.69 VRo % respectively. The developed burial history models have revealed that Bokh Shale hydrocarbon generation has been started during lower Jurassic, and presently hydrocarbon generation has been started within the “oil window” while Urandab Shale is immature to fairly mature.

Keywords

References

Abate E., Bruni P. and Sagri M. “Geology of Ethiopia: A Review and Geomorphological Perspectives,” Springer Netherlands, 2015, 33-64.
Astin T. R. and Worku T., “The Karoo Sediments: Late Palaeozoic to Early Jurassic of Ogaden Basin,” Ethiopia, 1991, 76, 7-21.
BEICIP F., “The Petroleum Potential Of Ethiopia, Beicip-Franlab Consultants Report For Ministry Of Mines And Energy,” Ethiopia, 1st ed, Addis Ababa, Ethiopia, 1985.
Beksa A. K., “Microfacies Analysis and Paleontology of Carbonate Rocks in Shanan Section,” South Eastern Ethiopia, 2017.
Boboye O. A. and Okon E. E., “Sedimentological and Geochemical Characterization of the Cretaceous strata of Calabar Flank,” Southeastern Nigeria, 2014.
Clift W. O., “Sedimentary History of the Ogaden district, Ethiopia,’’ Rep. 20th Int. Geol. Cong. Petrol. Gad Sympos., 1956, 78-112,
Corti G., “Control of Rift Obliquity on the Evolution and Segmentation of the Main Ethiopian Rift,” Nature Geosci., 2008, 1(4), 258-262.
Dawit L. E., “Adigrat Sandstone in Northern and Central Ethiopia: Stratigraphy, Facies, Depositional Environments and Palynology,” Doctoral Thesis, Technische Universität Berlin, Fakultät VI-Planen Bauen Umwelt, 2010.
Erik F., “Microfacies of Carbonate Rocks: Analysis, Interpretation and Application,” 1st ed., Institute of Palaeontology, Loewenichstrasse 28, Germany, 2004.
Gani M. G., Abdelsalam S. and Gani M. R., “Stratigraphic and Structural Evolution of the Blue Nile Basin, North-Western Ethiopian Plateau,” Geological Journal, 2009, 44, 30-56.
Gluyas J. and Swarbick R., “Petroleum Geoscience,” Oxford: Blackwell Publishing Co, 2009, 40-252.
Hallam A., “Jurassic Environments,” (Cambridge Earth Science Series) Reissue Edition, University of Oxford, UK, 2009.
Hankel O., “Early Permian to Middle Jurassic Rifting and Sedimentation in East Africa and Madagascar,” Springer, 1994, 83(4), 703-710.
Hantschel T. and Kauerauf A. I., “Fundamentals of Basin and Petroleum Systems Modelling,” Springer, 2009.
Hao F. and Chen J., “The Cause and Mechanism of Vitrinite Reflectance Anomalies,” Journal of Petroleum Geology, 1992, 15(4), 419-434.
Haq B. U., Hardenbol J. and Vail P. R., “Chronology of the Fluctuating Sea Level Since the Triassic,” Science, 1987, 235, 1156-1167.
Hunegnaw A., Sage L. and Gonnard R., “Hydrocarbon Potential of the Intracratonic Ogaden Basin,”Journal of Petroleum Geology, 1998, 21(4), 401-425.
Gluyas J. and Swarbrick R., “Petroleum Geosciences,” Amazon, 1st Ed. UK, 2004.
Martin B. and Geleta S., “A Planktonic Marker and Callovian-Oxfordian Fragmentation of Gondwana: Data from Ogaden Basin,” Palaeo, 1992, 104, 177-184.
Mascle J., Moungenot D., Blarez E., Marinho M., and et al., “African Transform Continental Margins: Examples from Guinea, Ivory Coast and Mozambique,” Geological Journal, 1987, 22, 537-561.
Maurice E. T., “Sedimentary Petrology: An Introduction to the Origin of Sedimentary Rocks,” 3rd ed. Department of Geological Sciences: University Of Durham, 2001.
Mengesha T., Tadiwos C. and Workneh H., “Explanation of the Geological Map of Ethiopia,” 2nd ed. Addis Ababa, Ethiopia, 1996.
Millard F. C. and Philip D. R., “Evolution of the Conjugate East African-madagascan Margins and the Western Somali Basin,” Model. J. Petrol. Geol., 1988.
Ministry of Mines of Ethiopia., “Joint Ogaden Basin Study Project” Petroleum Licensing & Administration, 2005.
Ministry of Mines of Ethiopia., “Petroleum Exploration in Ethiopia,” Petroleum Licensing & Administration, 2011.
Monson B., “Reflectance Measurement Manual,” Department of Geology, Queen University of Belfast: Belfast, 1995.
Morrison J., Birse A., Samuel M. A., Richardson S.M., and et al., “The Cretaceous Sequence Stratigraphy of the Socotran Platform,” Republic of Yemen, Marine and Petroleum Geology, 1997.
Moungenot D., Recq M., Virlogeux P., and Lepvrier C., “Seaward Extension of the East African Rift,” Nature, 1986, 321, 509-603.
Nabil M. A. and Mohammed A. A., “Petroleum Source Rocks Characterization and Hydrocarbon Generation of the Upper Jurassic Succession in Jabal Ayban Field, Sabatayn Basin, Yemen,” Egyptian Journal of Petroleum, Open Access, 2018.
Nick L., “Petroleum Resources in East Africa,” , EAC., 2010, 68-71.
Nton M. E. and Ekom J. C., “Hydrocarbon Generative Potential of Cretaceous Sediments of Kanadi-1 Well,” Bornu Basin, Nigeria, 2016.
Oladotun A., Oluwajana, Olugbenga A. and Ehinola, “Modelling Hydrocarbon Generation Potentials of Eocene Source Rocks in the Agbada Formation, Northern Delta Depobelt, Niger Delta Basin, Nigeria,” Journal of Petroleum Exploration and Production Technology, 2017, 7(2), 379-388.
Paolo B., “Landscapes and Landforms of Ethiopia,” World Geomorphological Landscapes, 2015, 326-340.
Peters K. E., “Assoc. Petroleum Geologists Bull,” 1986.
Peters K. E. and Cassa M. R., “Applied Source Rock Geochemistry; the Petroleum System-from Source to Trap Magoon,” Am Assoc Pet Geol Bull., 1994, 93-120.
Phan K., “Magnetic Data Processing for the Purpose of Hydrocarbon Exploration,” Institute of Geological Sciences, NCNST, 1999.
Premanand M. and Sagar N., “Using Remote Sensing and GIS Technologies as an Aid for Hydrocarbon Exploration in the Assam-Arakan Fold-thrust Belt,” Geology and Mineral Resource, Map India Conference, 2003.
Proeh T. S., ‘’Pore Pressures, Fracture Gradients, and Drilling Economics,” SPE/IADC Drilling Conference, Dallas, Texas, 1994.
Purcell P. G., “The Geology and Petroleum Potential of the Ogaden Basin, Ethiopia,”, Unpublished Report, 1979.
Shalaby M. R., Abdullah W. H., and Abu S., “Burial History, Basin Modelling and Organic Geochemistry in the Western Desert,” Egypt, Geological Society of Malaysia Bulletin, 2008.
Sweeney J. J. and Burnham A. K., “Evaluation of a Simple Model of Vitrinite Reflectance Based on Chemical Kinetics,” Assoc Am Pet Geol Bull., 1990, 74(10), 1559-1570.
Tissot B. P., Pelet R., and Ungerer P. H., “Thermal History of Sedimentary Basins, Maturation Indices and Kinetics of Oil and Gas Generation,” AAPG Bulletin, 1987, 71, 1445-1466.
Van Krevelen D. W., “Graphical-statistical Method for the Study of Structure and Reaction Processes of Hydrocarbons and Coal,” Fuel, 1950, 29, 228-269.
Wolela A., “Fossil Fuel Energy Resources of Ethiopia,” Bulletin of the Chemical Society of Ethiopia, 2007, 22, 67-84.
Wolela A., Alula H. G., and Belay W., “Sedimentology, Depositional Environments and Hydrocarbon Potential of the Yayu Basin,” Ministry Of Mines and Energy, Report, Petroleum Operations Department, 2002.
Worku T. and Astin T. R., “The Karoo Sediments: Late Paleozoic to Early Jurassic of Ogaden Basin, Ethiopia,” Sedimentary Geology, 1992, 76, 7-21.
Journal of Petroleum Science and Technology
Volume 8, Issue 4
December 2018
Pages 58-75

Files

Share

How to cite

Statistics