International Journal of Scientific & Engineering Research Volume 13, Issue 9, September-2022 1 ISSN 2229-5518 IJSER © 2022 http://www.ijser.org The Role of Clay Minerals in Hydrocarbon Generation, Migration and Accumulation. Ikoro D.O., Okeke O.C., Abubarkar M.T., Ogbonna T.L. And Ezebunanwa A. Geology Department, School of Physical Sciences, Federal University of Technology Owerri, Imo State, Nigeria. Corresponding author: toshiba2k8@gmail.com ABSTRACT This study focuses on the understanding of the role of clay minerals in hydrocarbon generation, migration and accumulation. Clay minerals are involved in the formation of kerogen, catalytic cracking of kerogen into petroleum, migration of crude oil, and the continued change to hydrocarbon composition in petroleum reservoirs. In kerogen formation, clay minerals act as catalysts and sorbents to immobilize organic matter through ligand exchange, hydrophobic interactions and cation bridges by the mechanisms of Maillard reactions, polyphenol theory, selective preservation and adsorptive protection. Clay minerals also serve as catalysts in acid- catalyzed cracking of kerogen into petroleum hydrocarbon through Lewis and Bronsted acid sites on the clay surfaces. The amount and type of clay mineral affect the composition of the petroleum. Bronsted acidity of clay minerals is affected by the presence and state of interlayer water, and displacement of this water is a probable driver in crude oil migration from source rocks. During crude oil migration and accumulation in reservoirs, the composition of petroleum is continually modified by interaction with clay minerals. Clay minerals remain the most difficult of all earth materials to study and characterize. Their sheet structure results in features that can only be resolved at the sub-micron scale. They are also subtly variable in chemical composition (Fe, Mg, K, Al, et cetera) and can be confused with each other and other silicates. The recent innovative analytical tools and modern analysis techniques, example., micro- and nano-X-ray Computed Tomography (XCT), QEMSCAN (Automated Mineralogy and Petrography), FIB/SEM (Focused Ion Beam/Scanning Electron Microscope), EDS (Energy-dispersive X-ray spectroscopy), etc., have the capability of quantitative and qualitative characterizing nano-pore features and mineralogy of fine grained shale rocks, which create new era of studying clay minerals for facilitating unconventional (shale) reservoir exploration. Even though there have been reports about the application of clay minerals in the oil and gas exploration, surprisingly little work has been documented. Keyword: clay mineral, organic matter, generation, vitrinite, kerogen, montmorillonite. INTRODUCTION Petroleum crude oil, or crude oil, is a naturally occurring oily, flammable liquid usually found in geologic formations deep beneath the surface of the earth. Crude oil consists mainly of hydrocarbons and polar organic compounds (resins, asphaltenes, etc.). The typical types of crude oil are light and heavy crude oil. Light crude oil contains more saturated hydrocarbons and less aromatic hydrocarbon, for example, naphtheno-paraffinic oil contains more than 50% saturated hydrocarbons and less than 40% paraffinic hydrocarbons, while heavy crude oil is referred to as any type of crude oil that does not flow easily. It is closely related to natural bitumen, which is distinguished by a high proportion of C15+ (Perrodon, 1983). Petroleum has played a IJSER