An evaluation of the hydrocarbon potentials of the gboko formation, middle benue trough, nigeria

Abstract

A total of seventeen (17) rock samples   from the Albian Gboko Formation were collected from the quarry of Benue Cement Company for organic geochemical analysis, in order to evaluate its hydrocarbon potential . Total Organic Carbon (TOC) values for the samples ranges from 0.11-0.5wt%.  The rock-eval data recorded S_2, hydrogen index (HI), Oxygen index (OI), T_max, and production index (PI) of 0.04-0.11, 25-54, 50-400, 310-461⁰C, and 0.4-0.6, respectively. These implies that the samples has a fair to poor source rock quality with a type IV kerogen. Optical methods (R₀, TAI & VKF) conducted on three selected samples of shales reveal vitrinite reflectance (R₀) of 0.77%, 1.11% and 1.54%, while thermal alteration index (TAI) recorded 2.7, 3.3 and 3.7.  Kerogen fluorescence indicated weak to non fluorescence. These results infer that the sediments had evolved from oil to gas window due to severe thermal effects . This indicates their potential to generate hydrocarbon gas