Publications

Microbial Enhanced Oil Recovery (MEOR) is one of the tertiary methodologies used to increase oil recovery. In conventional MEOR technology, the utilized or tested bacteria are indigenous to the reservoir, they are taken from the crude oil and connate water samples. The processing of bacteria taken from the samples (isolation process), the testing and the selecting of indigenous bacteria require a long time. The required time can be reduced significantly if an already proven MEOR bacterium from another reservoir can be utilized. In this study, proven MEOR bacteria from the Handil reservoir in Kalimantan (Flavimonas oryzihabitans, Amphibacillus xylanus, Bacillus polymyxa, Bacillus macerans, and Clostridium sp.) were used as nonindigenous bacteria on crude oil from a reservoir on Java Island. This study shows that there were changes in oil physical characteristics and composition after the oil is treated by bacteria. The viscosity decreased in the range of 0.042 to 0.407 centipoise (cP) with the best result demonstrated by A. xylanus. The density decreased in the range of 0.007 to 0.112 g/mL with the best result demonstrated by F. oryzihabitants. The interfacial tension decreased in the range of 0.54 to 4.18 dyne/cm with the best result demonstrated by Clostridium sp. In addition, gas production varied from 0.7 to 1.05% with the highest impact shown by B. polymixa. The Gas Chromatography (GC) analysis on oil composition showed that the crude oil was slightly degraded by bacteria. It can be concluded that Handil Field bacteria used in this experiment have potential as to be applied as nonindigenous bacteria for X reservoir in Java Island.