Isolation, screening and field applications of clostridial isolates to be used in Microbial Enhanced Oil Recovery (MEOR)

Scope and method of study. This project concerns the isolation and screening of bacterial isolates of the genus Clostridium and their application in the field for Microbial Enhanced Oil Recovery (MEOR). Preliminary screens included growth in the presence of 860 mM sodium chloride as well as the production of metabolic end-products capable of causing a release of oil from a reservoir. Secondary screens deleted pathogenic clostridia and those that produced hydrogen sulfide. In addition, the effect of various cores on the fermentation pattern were also investigated. This involved growth of isolate SEG-3 in the presence of powdered sandstone and limestone cores. Once a number of isolates were obtained, field studies were initiated in Kansas, Oklahoma and Texas. Viable spores and a suitable nutrient were injected into producing oil wells and the fermentations monitored.; Findings and conclusions. A number of isolates were obtained that were capable of producing desired end-products in the presence of 860 mM sodium chloride. Field studies indicate that spores can be injected into a reservoir at pressures up to 1,200 psia and survive. Complete fermentations occur in the reservoir and a biogenic gas can, to an extent, repressurize a portion of the reservoir. No detrimental effects on the oil wells were detected and although indications are that oil production can be increased no conclusions could be made.