Microbial biomass, activity, and community structure of water and particulates retrieved by backflow from a waterflood injection well
Oil field injection water was allowed to back flow from two wells at the Packard drill site in Los Angeles, Calif., and was sampled at various times to obtain information about the biomass, potential activity, and community structure of the microbiota in the reservoir formation and in the injection water. Biomass was greatest in water samples than came from the zone near the injection site and dropped off sharply in subsequent samples, which were assumed to come from zones farther away from the well. Samples obtained from near the well also had visible exopolysaccharide blankets, as seen in scanning electron microscopic preparations. In one of the wells that was sampled, rates of glucose or acetate incorporation into microbial lipids correlated with biomass; but in the other well, activities correlated with the sampling time (volume of water that back flowed). Transmission electron micrographs showed a diverse, gram-negative bacterial population in a variety of physiological states. The analysis of the phospholipid ester-linked fatty acid profiles of the samples revealed consistently large proportions of 18:1 omega7c fatty acids, indicating the presence of many anaerobes, facultative organisms, or both. Proportions of cyclopropyl fatty acids and ratios of trans/cis monoenoic compounds increased with the volume of water that back flowed (analogous with the distance into the formation), while the ratio of unsaturated/saturated compounds decreased, possibly indicating higher levels of stress or starvation in the microbial communities farthest from the injection well. Greater than 90% of the total biomass was trapped on glass fiber filters, indicating that the microbiota were largely attached to particles or were clumped.
- Research Organization:
- Univ. of Calgary, Alberta (Canada)
- OSTI ID:
- 6882177
- Journal Information:
- Appl. Environ. Microbiol.; (United States), Vol. 54:6
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
MICROBIAL EOR
MICROORGANISMS
ECOLOGY
OIL WELLS
BIOMASS
CARBOXYLIC ACIDS
PLUGGING
WATERFLOODING
ENERGY SOURCES
ENHANCED RECOVERY
FLUID INJECTION
ORGANIC ACIDS
ORGANIC COMPOUNDS
RECOVERY
RENEWABLE ENERGY SOURCES
WELLS
020300* - Petroleum- Drilling & Production
550700 - Microbiology