Abstract
An analytical procedure involving Rock-Eval pyrolysis of whole-rocks was adopted on fresh outcrop samples covering the three lithostratigraphic units in the Afikpo Basin of the Lower Benue Trough. Three petroleum systems are present in the Cretaceous delta frame: the Asu-River Group, the Eze-Aku Group and proto-Niger Delta sequences. The Afikpo Basin has been correlated to three petroleum systems in the Lower Congo Basin, Niger Delta and the Anambra Basin.
The organic geochemistry of the shales, carbonaceous mudstones and coal beds show relatively moderate to high total organic carbon contents. The best potential hydrocarbon source rocks are the Eze-Aku Group and proto-Niger Delta shales, carbonaceous mudstones and coal beds where maturation was attained. The high total organic contents, thermal maturity and terrigenous characters of the Asu-River Group, Eze-Aku Group and proto-Niger Delta sediments, suggest the presence of a large amount of natural gas with a small quantity of oil accumulation. Variations in source rock facies were observed from one lithostratigraphic unit to another, and initial HI values as a function of TOC were proposed for each lithostratigraphic unit. The results also show that TOC, HI, OI, S2 and T max vary from older to younger rocks. The T max values discriminate the rocks into immature and mature source rocks. Source rocks with high T max suggest high geothermal gradient/or recycled organic matter. Also high T max and S2 yield indicate late and post maturity. Recycled organic matter is characterized by low T max. The principal source rocks for gas in the Afikpo Basin are the Eze-Aku Group and proto-Niger Delta beds deltaic systems, consisting mainly of III to IV kerogens with a subordinate amount of type II organic matter. Based on the obtained results, it is concluded that the Cretaceous shales, carbonaceous mudstones and coals in the Afikpo Basin of the Lower Benue Trough are capable of generating and expelling hydrocarbons in the case of sufficient maturity.
Similar content being viewed by others
References
Agagu K.O. and Ekweozor C.M. (1982) Source rock characteristics of Senonian Shales in the Anambra Syncline, southern Nigeria [J]. Nigerian J. Min & Geol. 19, 52–61.
Agagu O.K. (1978) The Geology and Petroleum Potentials of Santonain to Maastrichtian Sediments in the Anambra Basin, Eastern Nigeria [D]. pp.250. Unpublished Ph.D. thesis, University of Ibadan, Nigeria.
Akande S.O., Ogunmoyero I.B., Peterson H.I., and Nytoft H.P. (2007) Source rock evaluation of coals from the Lower Maasstrichtain Mamu Formation, SE Nigeria [J]. Journal of Petroleum Geology. 30, 303–324.
Albrecht P. (1969) Constituent organiques des roches sedimentaires, Elude de la diagene dans une serie sedimentary epaisse: Univ. Strasboug Thesis.
Avbovbo A.A. (1978) Geochemical gradients in the southern Nigeria Basin [J]. Bull. Canadian Petroleum Geology. 26, 268–274.
Baskin D.K. (1997) Atomic H/C ratio of Kerogen as an estimate of thermal maturity and organic matter conversion [J]. APPG Bull. 81, 1437–1450.
Bernasconi S. and Riva A. (1993) Organic geochemistry and depositional environment of a hydrocarbon source rock: The Middle Triassic Grenzbitumenzone Formation, Southern Alps, Italy/Switzerland. In Generation, Accumulation and Production of Europe’s Hydroocarbons III (ed. Spencer A.M.) [M]. pp.179–190. European Ass. of Petrol. Geologists (Berlin), Special Publ. 3.
Benkhelil J. (1982) Benue Trough and the Benue Chain [J]. Geol. Mag. 119, 155–168.
Benkhelil J. (1989) The origin and evolution of the Cretaceous Benue Trough, Nigeria [J]. Journal Afric. Earth Sci. 8, 251–282.
Burke K.C., Dessauvagie T.F.J., and Whiteman A.J. (1971) Opening of the Gulf of Guinea and geological History of the Benue Depression and Niger. Delta [J]. Nat. Phy. Sci. 233, 51–55.
Burke K.C, Dessauvagie T.F.J, and Whiteman A.J. (1972) Geological history of the Benue valley and adjacent areas. In J. African Geology (eds. Dessauvagie T.F.J. and Whiteman A.J.) [M]. pp.187–206. Ibadan. Uni. Ibadan.
Dow W. (1977) Kerogen studies and geological interpretation [J]. J. Geochem. Exploration. 7, 79–98.
Espitalie J., Madec M., Tissot B., Mennig J.J., and Leplat P. (1977) Source Rock Characterization Methods for Petroleum Exploration [C]. pp.439–443.Proceedings Offshore Technology Conference.
Espitalie J., Deroo G., and Marqius F. (1985) La pyrolyse Rock-Eval et ses applications [J]. Revue de l’Insitute Francais du Petrole. 40, 563–579, 755–784.
Ekweozor C.M. and Okoye N.V. (1980) Petroleum source bed evaluation of Tertiary Niger Delta [J]. AAPG Bull. 64, 1251–1259.
Ekweozor C.M. and Gormly R. (1983) Petroleum geochemistry of Late Cretaceous and Early Tertiary Shales penetrated by the Akukwu-2 well in the Anambre basin, southern Nigeria [J]. J. Petroleum Geol. 6, 207–216.
Graham S.A. and Williams L.A. (1985) Tectonic depositional, and diagenetic history of Montercy formation (Miocene), Central San J oaquin Basin, Califonia [J]. AAPG. Bull. 69, 385–411.
Grant N.G. (1972) South Atlantic, Benue Trough and Gulf of Guinea Cretaceous Triple junction [J]. Bul. Geol. Soc. Am. 82, 2295–2298.
Guiraud M. (1993) Late Cretaceous Rifting-Early Cretaceous Rifting and Late Cretaceous transpressional inversion in the Upper Benue Basin (NE Nigeria). In Bulletin Des Centres De Recherches Expl-Prod Elf aquitaine. 17(2), 303–453.
Jovancicevic B., Wehner H., Scheerder G., Stojanovic K., Sainovic A., Cvetkovic O., Ercegovic M., and Vitorovic D. (2002) Search for source rocks of the crude oils of the Drmno depression (southern part of the Pannonian basin, Serbia) [J]. Journal of the Serbian Chemical Society. 67, 553–566.
Haack R.C., Sundararaman P., Diedjomahor J.O., Xiao H., Grant N.J., May E.D., and Kelsch K. (2000) Niger Delta petroleum systems, Nigeria. In Petroleum Systems of South Atlantic Margins (eds. Mello M.R. and Katz B.J.) [M]. AAPG Mem. 73, pp.213–231.
Milner C.W.D. (1982) Geochemical analyses of sedimentary organic matter and interpretation of maturation and source potential, SEPN shortcourse No. 7, p.217–252.
Mohriah W.U., Mello M.R., Bassetto M., Vieira I.S., and Koutsoukos E.A.M. (2000) Crustal Archecture, Sedimentation, and Petroleum systems in the Sergipe-Alagoas Basin, Northeastern Brazil. In Petroleum Systems of South Atlantic Margin (eds. Mello M.R. and Katz B.J.) [M]. APPG Memoir. 73, 273–300.
Murat R.C. (1972) Stratigraphy and Paleogeography of the Cretaceous and Lower Tertairy in Southern Nigeria. In African Geology (eds. Dessauvagie T.F.J. and Whiteman A.J.) [M]. pp.251–268. Univ. Ibadan Press.
Nwajide C.S. and Reijers T.J.A. (1996) The geology of the southern Anambra Basin. In Selected Chapters on Geology, Sedimentary Geology and Sequence Stratigraphy in Nigeria and Three case studies and Field Guide (ed. Reijers T.F.A.) [M]. pp.133–148. SPDC Shell Petroleum Development Company of Nigeria Corporate Reprographic Services, Warri.
Nwajide C.S. (2005) Anambra Basin of Nigeria: Synoptic Analysis as a Basis for evaluation its hydrocarbon prospectively. In Hydrocarbon Potentials of the Anambra Basin (ed. Okogbue C.O.) [M]. pp.1–46. Great AP Express Publishers LTD, Nigeria.
Nwachukwu S.O. (1985) Petroleum prospects of Benue Trough, Nigeria [J]. Bull. AAPG. 69, 601–609.
Obaje N.G. (2000) Biomarker Evaluation of the Oil-Generative Potential of organic matter in Cretaceous strata from the Benue Trough (Nigeria) [J]. NAPE Bull. 15(1), 29–46.
Odigi M.I. (2007) Facies Architecture and Sequence Stratigraphy of Cretaceous Formations, Southeastern Benue Trough, Nigeria [D]. pp.312. Unpublished Ph.D Thesis, Univ. Port Harcourt.
Odigi M.I. (in press) Ancient Conglomerate Basin-Fill Succession, Afikpo Basin, Southeastern Benue Trough, Nigeria.
Ofoegbu C.O., Ebeniro J., and Odigi M.I. (1989) On the tectonic evolution of theBenueTrough. In Benue Trough Structure & Evolution (ed. Ofoegbu C.O.) [M]. Friedr View & Sohn Earth Sci. 7, 203–216.
Offodile M.E. (1975) A review of the geology of the Benue Trough, Nigeria [J]. Journal African Earth Sciences. 3, 283–291.
Ojoh K.A. (1990) Cretaceous geodynamic evolution of the southern part of the Benue Trough (Nigeria) in the equatorial domain of the south Atlantic: Stratigraphy, Basin analysis, and paleo-oceanography [J]. Bull. Centres Resch. Explor-Prod. Elf-Aquitaine. 14(2), 419–442.
Olade M.A. (1975) Evolution of Nigeria’s Benue Trough (Aulacogen): A tectonic model [J]. Geol. Mag. 112, 575–583.
Petters S.W. (1980).Biostratigraphy of Upper Cretaceous foraminifera of the Benue Trough, Nigeria [J]. Journal Foram. Res. 10, 191–204.
Peters K.E. and Simoneit B.R.T. (1982) Rock-Eval pyrolysis of Quaternary sediments from Leg 64, Sites 479 and 480, Golf of California. In Initial Report of the Deep Sea Drilling Project (eds. Curray J.R. et al.) [M]. 64, 925–931.
Peters K.E. (1986) Guidelines for evaluating petroleum source rock using programmed pyrolysis [J]. AAPG Bull. 70, 318–329.
Peters K.E. and Cassa M.R. (1994) Applied source rock geochemistry. In The Petroleum System and Trap: AAPG Mem. (eds. Magoon L.B. and Dow W.G.) [M]. 60, 93–117.
Pratt L.M., Corner J.B., and Brassell S.C. (1992) Geochemistry of organic matter in sediments and sedimentary rocks [J]. SEPM Short Course. 37, 100.
Petters S.W and Ekweozor C.M. (1982) Petroleum geology of the Benue Trough and southeastern Chad basin, Nigeria [J]. AAPG Bull. 66, 1141–1149.
Peters K.E. and Moldowan J.M. (1993) Biomarker guide-Interpretating molecular fossils in petroleum and ancient sediments [M]. pp.363. Prentice-Hall, New Jersey.
Petersen H.I., Andsbjerg J., Bojesen-Koeford A., and Nytoft H.P. (2000) Coal-generated oil: Source rock evaluation and petroleum geochemistry of the Luhta oil field, Danish North Sea [J]. Journal of Petroleum Geology. 232, 55–90.
Penteado H.L.B. and Behar F. (2000) Geochemical characterization and compositional evolution of the Gormo Member source rocks in the Reconcavo Basin, Brazil. In Petroleum Systems of South Atlantic Margins (eds. Mello M.R. and Katz B.J.) [M]. AAPG Mem. 73, 179–194.
Reyment R.A. (1965) Aspects of the Geology of Nigeria Univ. [M]. pp.1–45.
Ibadan Press. Nigeria. Ronov A.B. (1958) Organic carbon in sedimentary rocks (in relation to presence of petroleum) [J]. Translations in Geochemistry. 5, 510–536.
Schoelkopf N.B. and Patterson B.A. (2000) Petroleum systems of offshore, Cabinda, Angola. In Petroleum Systems of South Atlantic Margin (eds. Mello M.R. and Katz B.J.) [M]. APPG Memoir. 73, 361–376.
Schoelkopf N.B. and Patterson B.A. (1997) Petroleum Systems of Cabinda, and Angola (abs) [C]. AAPG Symposium, Extended Abstract volume, Rio de Janeiro, Brazil.
Sidle W.C. and Richers D.M. (1985) Geochemical reconnaissance of Cretaceous inliers in North-central Oregon [J]. AAPG Bull. 69, 412–421.
Short K.C. and Stauble A.J. (1967) Outline of geology of the Niger Delta [J]. AAPG Bull. 54, 761–779.
Tissot B.P. and Welte D.H. (1984) Petroleum Formation and Occurrence [M]. pp.699. Springer-Verlag, New York.
Waples D.W. and Machihara T. (1991) Biomarkers for geological—A practical guide to the application of steranes and triteroanes in petroleum geology [J]. AAPG Methods in Exploration. 9, 91.
Whiteman A. (1982) Nigeria: Its Petroleum Geology, Resources and Potential [M]. Graham and Trotman Ltd., London. v. 1 & 2. 176.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Odigi, M.I., Amajor, L.C. Organic geochemical evaluation of the oil/gas-generative potential of organic matter in Cretaceous strata from the Lower Benue Trough, Nigeria. Chin. J. Geochem. 29, 233–241 (2010). https://doi.org/10.1007/s11631-010-0451-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11631-010-0451-9