
In this paper investigation was conducted to examine the effect of substrate characteristics medium (heavier hydrocarbon mixture in a reservoir) on the improvement of Microbial Entrained Oil Recovery (MEOR) in Niger Delta Area of Nigeria. The effect of substrate concentrate (heavier hydrocarbon) was demonstrated upon the action of the following microorganism, pseudomonas sp streptococcus sp, escheerichia coli, chromobacterium, bacillus sp. flavobacterium and micrococcus. Results obtained illustrates high growth rate in order of magnitude pseudomonas > bacillus sp. > eschevichia coli > flavobacterium > streptococcus > micrococcus > chromobiacterium. The rate of gas, water lighter hydrocarbon, biomass production from the degradation of the heavier hydrocarbon can be attributed to the effectiveness of the microbial activity in each reactor as well as the physicochemical properties of the substance favour the process. The experimental results obtained showed that the increase in gas, water, lighter hydrocarbon and biomass concentration with increase in period of exposure. The mathematical model developed in this paper was used in the simulation of the microbial growth and substrate kinetics. As the rate of production of products increases with microbial the rate of substrate concentration (heavier hydrocarbon) decreases. The research demonstrate the useful of various microorganism in improving microbial entrained oil Recovery (MEOR) in Niger Delta area of Nigeria using a favourable environment and physicochemical conditions.