An ESEM investigation into the effect of microbial biofilms on the wettability of quartz

摘要

The wettability relationships between oil, brine, gas and rock are of critical importance in understanding reservoir dynamics. Chemical surfactants, scale inhibitors and microbes introduced during exploration and production are all known to effect reservoir wettabilty. However, little thought has been given to the possibility of microbial contamination of cores during core preservation, handling, storage or analysis, and the effect that this may have on measuring parameters such as wettability. In an attempt to understand how wettability analysis of sandstone cores may be altered by the presence of microbial contamination, this paper examines the effect on wettability of bacterial-fungal biofilms on quartz. Wettability data for quartz, and quartz colonized by bacterial-fungal biofilms, were collected using an environmental scanning electron microscope (ESEM). The results illustrate that the introduction of biofilm to such systems can change wettability from hydrophilic to hydrophobic. These findings have important implications within the oil industry.