Publications

Microbial Enhanced Oil Recovery (MEOR) is a tertiary technology used to increase oil recovery by injecting microbes into the reservoir. One MEOR Indonesian research project was conducted on X field, Kepulauan Seribu. In this research, bacteria used were indigenous, i.e. originated from the crude oil and brine water sample of the reservoir. Based on previous research, Bacillus sp.1 and Bacillus sp.2 were the most potential isolates for this investigation since they had the best ability in decreasing natures of viscous oil. This research has focused on investigation of optimized conditions of this indigenous bacterial EOR system for recovery enhancement purposes. The bacteria, after being activated and adapted, were subjected to various bacterial inoculum ratios, nitrogen sources, and carbon sources. These were the main component for EOR system that required to be optimized. The examination and analysis of bacterial growth, oil physical characteristics, and oil hydrocarbon composition (by GC/MS test) from each component above would lead to the integrated optimized condition of bacterial system. During the study, improvement in oil physical characteristics and composition were: viscosity decreased from 5 to 13%, IFT decreased from 13 to 23%, and by GC/MS analysis on oil composition, the crude oil was slightly degraded by bacteria. Summarized from the results, optimum conditions for this system were 1:1 inoculum ratio (mix inoculum), molasses as much as 3% v/v (carbon source), and ammonium nitrate as much as 0,1% w/v (nitrogen source). These results will be used as reference for further applications in pilot and field scale.Keywords: indigenous, MEOR, bacteria, optimization, carbon, nitrogen, inoculum ratio, bacterial EOR system