Kerogen Type and Hydrocarbon Generation Guide for the Petroleum Exploration: Insights from Middle East Basins

Kerogen plays a fundamental role in petroleum systems, serving as the provider of hydrocarbon generation. This study examines the relationship between kerogen type and hydrocarbon generation across major oil-producing regions in Iraq, the Arabian Gulf (comprising Kuwait, Saudi Arabia, the United Arab Emirates, and Qatar), and Iran. While previous studies have offered general classifications of kerogen types, few have conducted regional comparative analyses that correlate organic matter characteristics with productivity in such geologically rich settings. This review synthesizes published geochemical and geological data to analyze the quantity and type of hydrocarbons generated from different kerogen types (I, II, III) within key source rock formations. The targeted source rocks are Yamama/Najmah, Sargelu, Naokelekan, Najmah-Sargelu, Marrat, Ratawi, Tuwaiq Mountain (Hanifa), Qusaiba, Hanifa, Shilaif, Uwainat, Kazhdumi/ Pabdeh, Gurpi, and Ilam. Type I kerogen, derived from lacustrine algae, has the highest oil potential, while Type II, from marine plankton, is both oil- and gas-prone. Type III, sourced from terrestrial plant material, predominantly generates gas, and Type IV is inert and non-productive. Results highlight the predominance of Type II kerogen across all regions, with significant variation in Total Organic Carbon, Hydrogen Index, and thermal maturity influencing oil versus gas generation. This study focuses on a regional scale to fill a fundamental gap in the literature, demonstrating that kerogen classification, combined with depositional environments and thermal maturity, provides a valuable framework. This integrated approach enhances hydrocarbon potential prediction and supports exploration strategies.