Laboratory Study on Adaptability of Anaerobic Bacteria to Different Salinities for the Purpose of Microbial Enhanced Oil Recovery at the Nord Sea

Abstract

This research is based on the study of microbial enhanced oil
recovery (MEOR) and the possibilities of its use in the Danish section
of the Nord Sea. The study applies experimental procedure to
investigate if anaerobic bacteria can survive under reservoir
conditions and produce products important in oil recovery. A
laboratory experiment was set up to simulate the salinity conditions
at the Nord Sea. Result showed that it was possible to increase the
adaptability limit of the considered bacteria growth to salinities up
to 140 g/l. Salinity of 20 g/l and 140 g/l has the highest and lowest
total gas production of 3970 ml and 110 ml respectively. A decline in
pH with time was observed across all salinity. The highest pH was
measured at 140 g/l also pH showed a direct correlation with
salinity. Electrical conductivity increases as pH increases, it also
increased with increasing salinity. The highest gas production was
after 24 hours and gas production across all salinities decreased
with increasing time. The highest gas production was between the pH
of 5 to 7. Gases produced during this experiment includes, carbon
dioxide, methane, nitrogen, traces of hydrogen sulphide, and two
other unknown gases which we were unable to detect. A linear model
was used to plot the relationship between various measured
parameters.