Hydrocarbon-Source Correlation in the Obayied Sub-Basin, North Western Desert, Egypt: Controls on Generation of Natural Gas and Light Crude Hydrocarbon Blends

Abstract

Obayied sub-basin provides one-third of the annual natural gas production in the Egyptian Western Desert. The origin of the Obayied hydrocarbons are however poorly constrained. In this study, the molecular biomarkers of the Obayied hydrocarbon blend were studied to infer on their origin and generation mechanism. The API values are in the range of (41.3°–53.7°) reflecting post-mature hydrocarbons. The molecular biomarkers suggest a generation of Obayied crude from clay-rich fluvio-deltaic source rocks. Age- and maturity-relevant biomarkers (e. g., Ts/Tm trisnorhopanes and methylphenanthrene indices) reflect a successive expulsion of the Obayied crudes from mature Jurassic rocks (>1%Ro). Biological markers correlate perfectly with those of the Jurassic Khatatba shale and coal extracts attesting. Additionally, the Obayied gases are wet, thermogenic and have been derived from a mature type III kerogen (1.3%Ro–2%Ro). The studied gases display compositional characteristics of mixed coal- and oil-type gases, and were therefore derived via primary cracking of the Khatatba coal as well as secondary cracking of the light liquid crudes. The present study clarifies the controls on the geochemical processes responsible for the accumulation of liquid and gas hydrocarbon mix in the deep as well as shallow inverted rift basins of the north Western Desert, Egypt.

References

[1] Abdel-AzizM, MoustafaA R, SaidS E D. Impact of Basin Inversion on Hydrocarbon Habitat in the Qarun Concession, Western Desert, Egypt. Proc. 14th EGPC Exp. Prod. Conf., Cairo, Egypt, 1998 139-155

[2] Abd El-GawadE A, MousaD A, LotfyM A, et al. . Origin of Bahariya Oil in Salam Oil Field, Western Desert-Egypt. Egyptian Journal of Petroleum, 2018, 27(4): 605-620

[3] AhmedM A, HassanM M A. Thermal Maturation Assessment of Multiple Organic-Rich Intervals in the Khatatba Formation and Its Influences on Hydrocarbon Potentiality, North East Abu Gharadig Concession, Elucidated by 1D Basin Modeling Approach. NRIAG Journal of Astronomy and Geophysics, 2019, 8(1): 55-72

[4] AllenP, AllenJ R. Basin Analysis: Principles and Application to Petroleum Play Assessment, 2013 Chichester Wiley-Blackwell 640

[5] AlsharhanA S, Abd El-GawadE A. Geochemical Characterization of Potential Jurassic/Cretaceous Source Rocks in the Shushan Basin, Northern Western Desert, Egypt. Journal of Petroleum Geology, 2008, 31(2): 191-212

[6] AyyadM H, DarwishM. Syrian Arc Structures: A Unifying Model of Inverted Basins and Hydrocarbon Occurrences in North Egypt. Proc. 13th EGPC Exp. Prod. Conf., Cairo, Egypt, 1996 40-59

[7] BernardB B, BrooksJ M, SackettW M. Light Hydrocarbons in Recent Texas Continental Shelf and Slope Sediments. Journal of Geophysical Research: Oceans, 1978, 83(C8): 4053-4061

[8] BernerU, FaberE. Empirical Carbon Isotope/Maturity Relationships for Gases from Algal Kerogens and Terrigenous Organic Matter, Based on Dry, Open-System Pyrolysis. Organic Geochemistry, 1996, 24(10): 947-955

[9] BorehamC J, CrickI H, PowellT G. Alternative Calibration of the Methylphenanthrene Index Against Vitrinite Reflectance: Application to Maturity Measurements on Oils and Sediments. Organic Geochemistry, 1988, 12(3): 289-294

[10] BosworthW, TariG. Hydrocarbon Accumulation in Basins with Multiple Phases of Extension and Inversion: Examples from the Western Desert (Egypt) and the Western Black Sea. Solid Earth, 2021, 12(1): 59-77

[11] ChenZ L, LiS J, WangZ. A Study on Maturity Indicators of Some Aromatics in Low-Mid Maturity Thermal Evolution Zones. Acta Sedimentologica Sinica, 1997, 15(2): 192-197 (in Chinese with English Abstract)

[12] ChungH M, GormlyJ R, SquiresR M. Origin of Gaseous Hydrocarbons in Subsurface Environments: Theoretical Considerations of Carbon Isotope Distribution. Chemical Geology, 1988, 71(1/2/3): 97-104

[13] DaiJ X. Identification of Various Alkane Gases. Science China Earth Sciences, 1992, 35(10): 1246-1257

[14] DemaisonG, HuizingaB J. Generic Classification of Petroleum Systems. AAPG Bulletin, 1991, 75(10): 1626-1643

[15] DolsonC J, ShaanV M, MatboulyS, et al. . The Petroleum Potential of Egypt. AAPG Bulletin, 1999, 83(12): 1-37

[16] DowW G. Application of Oil-Correlation and Source-Rock Data to Exploration in the Williston Basin. AAPG Bulletin, 1974, 58: 1253-1262

[17] Egyptian General Petroleum Corporation (EGPC). Western Desert, Oil and Gas Fields, a Comprehensive Overview. Proc. 11th EGPC Exp. Prod. Conf., Cairo, Egypt, 1992 431

[18] Egyptian General Petroleum Corporation (EGPC). Petroleum Sector Companies’ Performance for the Financial Year of 2017/2018, 2018 Internal Report, Unpublished

[19] El DiastyW S. Khatatba Formation as an Active Source Rock for Hydrocarbons in the Northeast Abu Gharadig Basin, North Western Desert, Egypt. Arabian Journal of Geosciences, 2015, 8(4): 1903-1920

[20] El DiastyW S, MoldowanJ M. Application of Biological Markers in the Recognition of the Geochemical Characteristics of some Crude Oils from Abu Gharadig Basin, North Western Desert—Egypt. Marine and Petroleum Geology, 2012, 35(1): 28-40

[21] El MatbolyE, LeilaM, PetersK, El DiastyW. Oil Biomarker Signature and Hydrocarbon Prospectivity of Paleozoic versus Mesozoic Source Rocks in the Faghur-Sallum Basins, Egypt’s Western Desert. Journal of Petroleum Science and Engineering, 2022, 217: 110872

[22] El NadyM M, RamadanF S, EysaE A, et al. . The Potentiality of Hydrocarbon Generation of the Jurassic Source Rocks in Salam-3x Well, North Western Desert, Egypt. Egyptian Journal of Petroleum, 2016, 25(1): 97-105

[23] EspitaliéJ, UngererP, IrwinI, et al. . Primary Cracking of Kerogens. Experimenting and Modelling C₁, C₂–C₅, C₆–C₁₅ and C₁₅ Classes of Hydrocarbons Formed. Organic Geochemistry, 1988, 13(4/5/6): 893-899

[24] GarfunkelZ. Origin of the Eastern Mediterranean Basin: A Reevaluation. Tectonophysics, 2004, 391(1/2/3/4): 11-34

[25] GranthamP J. The Occurence of Unusual C₂₇ and C₂₉ Sterane Predominances in Two Types of Oman Crude Oil. Organic Geochemistry, 1986, 9(1): 1-10

[26] GuiraudR. Mesozoic Rifting and Basin Inversion along the Northern African Tethyan Margin: An Overview. In: Macgregor, S. D., Moody, J. T. R., Clark Lowes, D. D., eds., Petroleum Geology of North Africa. Geological Society of London, Special Publication, 1998, 132(1): 217-229

[27] GuiraudR, BosworthW. Phanerozoic Geodynamic Evolution of Northeastern Africa and the Northwestern Arabian Platform. Tectonophysics, 1999, 315(1/2/3/4): 73-104

[28] GuiraudR, BosworthW. Senonian Basin Inversion and Rejuvenation of Rifting in Africa and Arabia: Synthesis and Implications to Plate-Scale Tectonics. Tectonophysics, 1997, 282(1/2/3/4/5): 39-82

[29] GuoX W, HeS. Aromatic Hydrocarbons as Indicators of Origin and Maturation for Light Oils from Panyu Lower Uplift in Pearl River Mouth Basin. Journal of Earth Science, 2009, 20(5): 824-835

[30] HassanM, LeilaM, AhmedM, et al. . Geochemical Characteristics of Natural Gases and Source Rocks in Obayied Sub-Basin, North Western Desert, Egypt: Implications for Gas-Source Correlation. Acta Geochimica, 2023, 42(2): 241-255

[31] HolbaA G, DzouL I, WoodG D, et al. . Application of Tetracyclic Polyprenoids as Indicators of Input from Fresh-Brackish Water Environments. Organic Geochemistry, 2003, 34(3): 441-469

[32] HuangW Y, MeinscheinW G. Sterols as Ecological Indicators. Geochimica et Cosmochimica Acta, 1979, 43(5): 739-745

[33] HughesW B, HolbaA G, DzouL I P. The Ratios of Dibenzothiophene to Phenanthrene and Pristane to Phytane as Indicators of Depositional Environment and Lithology of Petroleum Source Rocks. Geochimica et Cosmochimica Acta, 1995, 59(17): 3581-3598

[34] HuntJ M, HucA Y, WhelanJ K. Generation of Light Hydrocarbons in Sedimentary Rocks. Nature, 1980, 288: 688-690

[35] HuntJ M. Petroleum Geochemistry and Geology, 1996 2nd Edition San Francisco W. H. Freeman 743

[36] JarvieD M, ClaxtonB L, HenkF, et al. . Oil and Shale Gas from the Barnett Shale, Fort Worth Basin, Texas. AAPG National Convention, Denver, USA, 2001, 10(13): A100

[37] LeilaM, LévyD, BattaniA, et al. . Origin of Continuous Hydrogen Flux in Gas Manifestations at the Larderello Geothermal Field, Central Italy. Chemical Geology, 2021, 585: 120564

[38] LeilaM, MoscarielloA. Organic Geochemistry of Oil and Natural Gas in the West Dikirnis and el-Tamad Fields, Onshore Nile Delta, Egypt: Interpretation of Potential Source Rocks. Journal of Petroleum Geology, 2017, 40(1): 37-58

[39] LeilaM, AwadallaA, FaragA, et al. . Organic Geochemistry and Oil-Source Rock Correlation of the Cretaceous Succession in West Wadi El-Rayan (WWER) Concession: Implications for a New Cretaceous Petroleum System in the North Western Desert, Egypt. Journal of Petroleum Science and Engineering, 2022, 219: 111071

[40] LeilaM, LoiseauK, MorettiI. Controls on Generation and Accumulation of Blended Gases (CH₄/H₂/He) in the Neoproterozoic Amadeus Basin, Australia. Marine and Petroleum Geology, 2022, 140: 105643

[41] LeilaM, YasserA, El BastawesyM, et al. . Seismic Stratigraphy, Sedimentary Facies Analysis and Reservoir Characteristics of the Middle Jurassic Syn-Rift Sediments in Salam Oil Field, North Western Desert, Egypt. Marine and Petroleum Geology, 2022, 136: 105466

[42] LetouzeyJ. Cenozoic Paleo-Stress Pattern in the Alpine Foreland and Structural Interpretation in a Platform Basin. Tectonophysics, 1986, 132(1/2/3): 215-231

[43] LiuQ Y, WuX Q, WangX F, et al. . Carbon and Hydrogen Isotopes of Methane, Ethane, and Propane: A Review of Genetic Identification of Natural Gas. Earth-Science Reviews, 2019, 190: 247-272

[44] MackenzieA S, QuigleyT M. Principles of Geochemical Prospect Appraisal. AAPG Bulletin, 1988, 72(4): 399-415

[45] MangoF D. The Origin of Light Hydrocarbons in Petroleum: Ring Preference in the Closure of Carbocyclic Rings. Geochimica et Cosmochimica Acta, 1994, 58(2): 895-901

[46] MetwalliF I, PigottJ D. Analysis of Petroleum System Criticals of the Matruh-Shushan Basin, Western Desert, Egypt. Petroleum Geoscience, 2005, 11(2): 157-178

[47] MilkovA V, EtiopeG. Revised Genetic Diagrams for Natural Gases Based on a Global Dataset of >20 000 Samples. Organic Geochemistry, 2018, 125: 109-120

[48] MoldowanJ M, DahlJ, HuizingaB J, et al. . The Molecular Fossil Record of Oleanane and Its Relation to Angiosperms. Science, 1994, 265(5173): 768-771

[49] MoldowanJ M, SeifertW K, GallegosE J. Relationship between Petroleum Composition and Depositional Environment of Petroleum Source Rocks. AAPG Bulletin, 1985, 69(8): 1255-1268

[50] PetersK E, MoldowanJ M. Effects of Source, Thermal Maturity, and Biodegradation on the Distribution and Isomerization of Homohopanes in Petroleum. Organic Geochemistry, 1991, 17(1): 47-61

[51] PetersK E, MoldowanJ. The Biomarker Guide. Interpreting Molecular Fossils in Petroleum and Ancient Sediments, 1993 Englewood Cliffs, NJ Prentice-Hall 363

[52] PetersK E, WaltersC C, MoldowanJ M. The Biomarker Guide, 2005 2nd Ed. New York Cambridge University Press 1155

[53] PrinzhoferA, BattaniA. Gas Isotopes Tracing: an Important Tool for Hydrocarbons Exploration. Oil & Gas Science and Technology, 2003, 58(2): 299-311

[54] RadkeM, LeythaeuserD, TeichmüllerM. Relationship between Rank and Composition of Aromatic Hydrocarbons for Coals of Different Origins. Organic Geochemistry, 1984, 6: 423-430

[55] RadkeM, WelteD H. ColomboU, HobsonG D. The Methylphenanthrene Index (MPI): A Maturity Parameter Based on Aromatic Hydrocarbons. Advances in Organic Geochemistry, 1983 Chichester Wiley Press 504-512

[56] RadkeM, WelteD H, WillschH. Geochemical Study on a Well in the Western Canada Basin: Relation of the Aromatic Distribution Pattern to Maturity of Organic Matter. Geochimica et Cosmochimica Acta, 1982, 46(1): 1-10

[57] RadwanA A, NabawyB S, ShihataM, et al. . Seismic Interpretation, Reservoir Characterization, Gas Origin and Entrapment of the Miocene-Pliocene Mangaa C Sandstone, Karewa Gas Field, North Taranaki Basin, New Zealand. Marine and Petroleum Geology, 2022, 135: 105420

[58] SassenR, JoyeS, SweetS T, et al. . Thermogenic Gas Hydrates and Hydrocarbon Gases in Complex Chemosynthetic Communities, Gulf of Mexico Continental Slope. Organic Geochemistry, 1999, 30(7): 485-497

[59] Schlumberger. Geology of Egypt, Well Evaluation Conference, 1984 Cairo Schlumberger 1-64

[60] Schlumberger. Geology of Egypt Well Evaluation Conference, 1995 Cairo Schlumberger 58-66

[61] SchoellM. Genetic Characterization of Natural Gases. AAPG Bulletin, 1983, 67: 2225-2238

[62] SchoellM. Multiple Origins of Methane in the Earth. Chemical Geology, 1988, 71(1/2/3): 1-10

[63] SeifertW K, MoldowanJ M. Applications of Steranes, Terpanes and Monoaromatics to the Maturation, Migration and Source of Crude Oils. Geochimica et Cosmochimica Acta, 1978, 42(1): 77-95

[64] SeifertW K, MoldowanJ M. The Effect of Biodegradation on Steranes and Terpanes in Crude Oils. Geochimica et Cosmochimica Acta, 1979, 43(1): 111-126

[65] ShalabyM R, HakimiM H, AbdullahW H. Geochemical Characteristics and Hydrocarbon Generation Modeling of the Jurassic Source Rocks in the Shoushan Basin, North Western Desert, Egypt. Marine and Petroleum Geology, 2011, 28(9): 1611-1624

[66] ShalabyM R, HakimiM H, AbdullahW H. Petroleum System Analysis of the Khatatba Formation in the Shoushan Basin, North Western Desert, Egypt. Arabian Journal of Geosciences, 2014, 7(10): 4303-4320

[67] ShanmugamG. Significance of Coniferous Rain Forests and Related Organicmatter in Generating Commerical Quantities of Oil, Gippsland Basin, Australia. AAPG Bulletin, 1985, 69(8): 1241-1254

[68] SoferZ. Stable Carbon Isotope Compositions of Crude Oils: Application to Source Depositional Environments and Petroleum Alteration. AAPG Bulletin, 1984, 68(1): 31-49

[69] StahlJ W. TissotB, BiennerF. Carbon Isotope Ratios of German Natural Gases in Comparison with Isotopic Data of Gaseous Hydrocarbons from Other Parts of the World. Advances in Organic Geochemistry, 1973 Paris Editions Technip Pub. 453-462

[70] StampfliG M, BorelG D, CavazzaW, et al. . Palaeotectonic and Palaeogeographic Evolution of the Western Tethys and PeriTethyan Domain (IGCP Project 369). Episodes, 2001, 24(4): 222-228

[71] ThompsonK F M. Classification and Thermal History of Petroleum Based on Light Hydrocarbons. Geochimica et Cosmochimica Acta, 1983, 47(2): 303-316

[72] ThompsonK F M. Fractionated Aromatic Petroleums and the Generation of Gas-Condensates. Organic Geochemistry, 1987, 11(6): 573-590

[73] TissotB P, WelteD H. Petroleum Formation and Occurrence, 1984 2nd Ed. New York Springer-Verlag 699

[74] TorfsteinA, SteinbergJ. The Oligo–Miocene Closure of the Tethys Ocean and Evolution of the Proto-Mediterranean Sea. Scientific Reports, 2020, 10: 13817

[75] WaplesD, MachiharaT. Biomarkers for Geologists. A Practical Guide to the Application of Steranes and Triterpanes in Petroleum Geology. AAPG Methods in Exploration, 1991, 9: 91

[76] WeverH E. Petroleum and Source Rock Characterization Based on C₇ Star Plot Results: Examples from Egypt. AAPG Bulletin, 2000, 84(7): 1041-1054

[77] WhiticarM J. Carbon and Hydrogen Isotope Systematics of Bacterial Formation and Oxidation of Methane. Chemical Geology, 1999, 161(1/2/3): 291-314

[78] WhiticarM J, FaberE, SchoellM. Biogenic Methane Formation in Marine and Freshwater Environments: CO₂ Reduction vs. Acetate Fermentation—Isotope Evidence. Geochimica et Cosmochimica Acta, 1986, 50(5): 693-709

[79] WilliamsJ. Characterization of Oil Types in Williston Basin. AAPG Bulletin, 1974, 58(7): 1243-1252

[80] YasserA, LeilaM, El BastawesyM, et al. . Reservoir Heterogeneity Analysis and Flow Unit Characteristics of the Upper Cretaceous Bahariya Formation in Salam Field, North Western Desert, Egypt. Arabian Journal of Geosciences, 2021, 14(16): 1635

[81] YounesM A A. Alamein Basin Hydrocarbon Potential of the Jurassic–Cretaceous Source Rocks, North Western Desert, Egypt. Oil Gas European Magazine, 2002, 28(3): 22-28

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