Using Microbes to Enhance Oil Recovery
After decades of oil recovery from conventional oil reservoirs, using techniques like water flooding, steam injection, and horizontal drilling to recover oil, approximately 65% of all discovered oil still remains trapped in the ground — most of it unrecoverable using current techniques. As easily recoverable oil becomes scarcer, attention must focus on new technologies to access this vast resource. These technologies commonly fall under the term Enhanced Oil Recovery (EOR), and have included a wide range of experimental approaches, some with considerable success, such as C02 miscible flooding.
The oil and gas industry is vital to the Prairie region with its vast and rich oil reserves. However, much of the oil in the region occurs in unique geological formations which make long-term oil recovery difficult and costly. The Microbial Enhanced Oil Recovery (MEOR) research project led by Genome Prairie is using biotechnology and genomics to develop novel tools to increase productivity and oil recovery from existing oil wells. The project takes a genomic fingerprint of an oil well to create a tailor made nutritional formula that will stimulate the naturally present micro-organisms in the oil well to help release trapped, hard-to extract oil. The new technology will reduce the risk of lethal sour gas forming in these wells and provide more efficient extraction by reducing water usage.
Research ResultsResearch Results
The conventional approach to MEOR was previously an empirical process, using inexpensive nutrients pumped into a reservoir to stimulate growth of indigenous microorganisms. In theory, the rejuvenated microbial community produces metabolic by-products such as gases, acids, solvents, surfactants and polymers that aid in releasing trapped oil, and/or biomass and polymers that plug “thief zone” water channels. Subsequent water or gas floods into oil-bearing zones can then result in significant recovery of trapped oil. Unfortunately, conventional MEOR has been a hit-or-miss process, often with little success. In some cases, undesirable by-products such as hydrogen sulfide have caused irreversible reservoir damage and equipment corrosion. The problem has been that one cannot predict what metabolic response, if any, can be expected in an oil reservoir when nutrients are injected. Recognizing the deficiencies in conventional, empirical MEOR, this project provided an innovative and rigorous scientific approach to MEOR known as Deductive MEOR.
Notable OutcomesNotable Outcomes
Initial studies collected down-hole samples from an operational well using a technique that maintained the environmental conditions of the collection point.
Laboratory experiments confirmed that microbial growth under simulated down-hole conditions can be driven to eliminate the production of sour gas (hydrogen sulfide) and stimulate desirable metabolic activity.
Metagenomics—an emerging field in which DNA sequencing is used to identify individual microbes from a complex sample containing a community of microbes—was used to identify several new bacterial species and analyze their response to selected nutritional formulas.