
BROWN, LEWIS R., VADIE, ALEX A., Mississippi State University and STEPHENS, JAMES O., Hughes Eastern Corporation, Jackson, MS
This paper will report on a field demonstration of the ability of in-situ
indigenous microorganisms to reduce the flow of injection water in the
more permeable zones thereby diverting flow to other areas of the reservoir,
thus increasing the efficiency of the waterflooding operation. At the outset,
a well was drilled and a core was obtained therefrom for core flood experiments
to determine the schedule and amounts of nutrients to be employed in the
field. The field demonstration involves injecting nutrients (KNO3,
NaH2PO4, and molasses) into four injector wells (test)
and comparing the performance of the surrounding producer wells to the
producers surrounding four untreated injector wells (control).
After two years of treatment, three new wells were drilled within the
field and cores have shown the presence of injected nutrients (nitrate
and phosphate ions) indicating their wide distribution in the reservoir.
Electron microscopic examination of the cores has shown the presence of
large numbers of bacteria suggesting that they are being stimulated to
multiply by the added nutrients.
Two of the four test injectors wells are experiencing an increase in
injection pressure and a decrease in fluids pumped indicating resistance
probably caused by microbial growth in the reservoir. Based on improved
oil production and/or Water:Oil Ratios, 8 of the 15 producing wells in
the four test patterns are responding favorably while the producers in
the four control patterns have continued their natural decline in performance.