Source Rock Potential Through Geological Time
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The document discusses the factors influencing the potential of oil source rocks, emphasizing basin restriction, nutrient levels, sedimentation rates, and sea-level changes. It highlights the significance of climate and geological events, such as super-plumes, in the formation and preservation of organic matter. Additionally, it outlines examples of rich source rocks in various global regions, particularly in the context of North Africa and the Arabian Gulf.
Source Rock Potential Through Geological Time
- 1. Prof. Dr. Hassan Z. Harraz Geology Department, Faculty of Science, Tanta University hharraz2006@yahoo.com Spring 2019 a function of Basin Restriction, Nutrient Level , Sedimentation Rate & Sea-level Rise
- 2. Basin Restriction's Impact on Source Rocks Climate (Rain Shadow & Green House versus Ice House) Transgressions Super-plumes (Nutrients) Sweet Spots! Basin Phase (extension, compression, or barred) Middle East North Africa Precambrian Continents World Neoproterozoic Petroleum Systems Karelian Shungites World's Source Rocks Outline 2
- 3. Others 112B Bbls - 10% FSU 78B Bbls - 7% South America 62B Bbls - 5% North Africa 60B Bbls - 5% West Africa 46B Bbls - 4% Regional Distribution of Global Oil Reserves North Sea 14B Bbls - 1% North America 62B Bbls - 4% 3 Middle East 734B Bbls - 64%
- 4. Plate Extension, Convergence or Barred Climate (Rain Shadow) Low Sediment Marine Transgression Super Plume Nutrient Restricted Basin 4
- 5. Devonian Ohio Shale I 64 Kty (Kendall Photo) Enable higher concentrations organic carbon: Allocthonous Autothonous Preserved in: Black (Anoxic) Shale (Anoxic) Carbonates Basin Restriction & Anoxia 5
- 7. Transgressive Beat To Mesozoic & Tertiary Source Rocks 7
- 8. Climate and Source Rock Potential 8 Cyclic Changes in: Climate, Sea Position, Organic Productivity and Sequestration
- 9. Climate and Source Rock Potential 9 Cyclic Changes in: Climate, Sea Position, Organic Productivity and Sequestration
- 10. Very fast Seafloor spreading. Enhanced organic production of oceans from massive amounts of CO2 from oceanic lava flows. Produce oceanic anoxic events (OAEs) & super- greenhouse events in Mesozoic. Organic matter preserved by anoxia on sea floor with accumulation of organic rich sediments. Super-plume Forcing of Organic Production 10
- 11. Super Plumes & Time (Abbot & Isley 2002) Phanerozoic! Plumes : A Nutrient Beat! 11
- 12. Sweet Spot! i) Break Up Margin - Mesozoic of Northern Atlantic: Isolated linear belt of interior drainage, Restricted entrances to sea, Regional drainage away from margin , Arid tropics air system Wide envelope of surrounding continents, and Juxtaposed source, seal & reservoir, ii) Collision Margin Restricted Basin: Regional drainage into basin, Isolated linear belt of interior drainage, Restricted entrance to sea, Regional drainage away from margin , Arid tropics air system Wide envelope of surrounding continents, and Juxtaposed source, seal & reservoir, 12
- 13. 13 Break Up - Mesozoic of Northern Atlanticrestricted entrances to sea regional drainage away from margin arid tropics air system wide envelope of surrounding continents SWEET SPOT! juxtaposed source, seal & reservoir
- 14. Examples of Organic rich rocks at Break Up Margins: 14 Mesozoic of Northern Gulf of Mexico Mesozoic of North & South Atlantic Margins Mesozoic of Yemen Rift Belt Mesozoic & Tertiary of Eritrea East African Rift Dead Sea
- 15. 15 restricted entrance to sea isolated linear belt of interior drainage regional drainage into basin arid tropics air system wide envelope of surrounding continents SWEET SPOT! juxtaposed source seal & reservoir Arabian Gulf Collision Margin Restricted Basin
- 16. Examples of Organic rich rocks at Collision Margins 16 Current Arabian Gulf & underlying Late Mesozoic to Tertiary. Silurian of Michigan Basin & Western New York State. Devonian of Western Canada & NW USA . Permian of New Mexico & West Texas. Permian of Zechstein Basin. Mesozoic to Tertiary of Southern South America. Tertiary of Mediterranean. Mesozoic & Tertiary in final phases of Tethys Sea.
- 17. Example of Barred Basin Mesozoic - Arabian Gulf 17 Upper Jurassic Saudi Arabia Kuwait, Iran & UAE restricted entrance to sea structural & depositional barrier over Hercynian horst blocks arid tropical air system wide shadow from adjacent continents SWEET SPOT! juxtaposed source seal & reservoir
- 18. Most are carbonate plays beneath evaporite seals in restricted basins juxtaposing source, seal and reservoirs 18 Location of Oil & Gas Fields of Arabian Gulf - Reservoirs are Younger to East 18
- 19. Restricted Basins Isolated by Build Up Barriers Organic Rich Fill Arabian Gulf Jurassic 19After Fox & Albrandt,200219
- 20. Regional Upper Cretaceous (Senonian) Petroleum Source in argillaceous limestones of North Africa Lower Paleozoic of North Africa proven and prolific plays eg: Tanezzuft Shale of Libya North African Source Rocks 20
- 21. Two major source rocks distribution around Mediterranean Modified from varies sources 21
- 22. Precambrian Continents Precambrian play of North Africa “is still immature & deserves more investigation” quote from Jonathon Craig – ENI. Large autochthonous accumulations of organic matter Rare in Precambrian rocks. Occurs in Paleoproterozoic sedimentary rocks as coal-like material. Derived from Precambrian oil? Potential matches younger oil plays? Precambrian Oil? 22
- 23. World Neoproterozoic Petroleum Systems Proven South Punjab (Bikner-Nagaur) Basin, Pakistan - India South Oman Salt Basin Taoudenni Basin Mauritania, Mali, Algeria Sirte, Cyrenaica Basin, Libya Murzuq Basin SW Libya Ahnet Basin Algeria Tindouf Basin Morocco, Algeria Potential Potwar Basin Kufra Basin SW Libya Argentina Bolivia, & Paraguay USA Nonesuch Michigan Amadeus, Officer & McArthur Basin Volga Ural Province Lena-Tunguske Province, Siberia After Jonathon Craig - ENI 23
- 24. World Record Holder Karelian Shungites 24 Precambrian Shunga Event ~2.0 Ga Paleoproterozoic ~ 2.0 Ga, Shunga-NW Russia. 600 m thick Upper Zaonezhskaya Formation. Rich in organic carbon: Corg up to 98%; averages 25% over 9000 km2 along narrow rifted margin. Include coal-like seams of layered shungite , cross- cutting diapirs & veins of remobilized liquid petroleum. Plume caused magmatism &/or volcanism Interlayered with mafic volcanic rocks.
- 25. Karelian Shungites V.A. Melezhik et al. 1999 25
- 26. Now for a few barrels of oil! 26
- 27. World wide stratigraphic distribution of major source rocks Stratigraphic distribution of the major reservoir rocks world wide (Modified from Ulmashek and Klemme, 1990) World's Source Rocks & Reservoirs 27
- 28. World's Source Rocks 28 World source rock potential through geological time is a function of: Basin Restriction, Nutrient Level , Sedimentation Rate, and Sea-level Rise. Contain higher concentrations of allocthonous vs. autothonous organic carbon preserved in: i) Black (Anoxic) Shale ii) (Anoxic) Carbonates Have irregular temporal beat driven by: i) Climatic response: Rain shadow East coast/west coast ocean circulation Monsoons ii) World wide transgressions & restricted basins iii) Sporadic super-plumes iv) Basin restriction: Continental plate configuration: Initial extension Final collision Structural barriers and/or buildup barriers.
- 29. 29 World's Source Rocks …(cont.) Most of world's largest oil fields restricted to Southern Tethyan Margin Principal Oil Provinces matching this paradigm: Mesozoic Lee Shore of Pangea: Eastern Arabian Shelf Giant Fields Southern Mediterranean Margin Early Silurian section of northern Gondwanaland (ice cap melt, & transgression) Tanezzuft Shale of Libya