IT’S been a long road to commercial application, but some experts believe that the perennial weak sister of enhanced oil recovery (EOR), the cultivation of production-boosting micro-organisms in the reservoir, is starting to show some strength.
Microbial activity in oil reservoirs is common and a general understanding of the role of some microbial processes in oil reservoirs has been around for decades. For instance, types of micro-organisms degrade oil to produce CO2 and methane in the presence of water. Over geological time, such a process has resulted in Canada’s oil sands. Some microbial byproducts can lower oil viscosity. Microbial activity can also produce a biomass that plugs up unwanted flow paths in a reservoir. These processes can be used to boost oil production and are known as microbial enhanced oil recovery (MEOR). While microbial-related corrosion prevention is a proven technology, harnessing microbial activity for MEOR has historically been a rather hit-and-miss affair over much of the last quarter century.
Recent laboratory work has accessed the latest measurement and analytic technologies and tools to improve the accuracy of its findings and still came up with some promising results. Growing numbers of field trials, pilots and, indeed, commercial projects are starting to show relatively consistent incremental production with MEOR, especially when compared to the spotty record of the past. A recent flurry of Society of Petroleum Engineers (SPE) papers, besides attesting to these successes, signals a general upswing of interest in MEOR. Oil and gas majors and some large intermediates have been hiring microbiologists recently, says Gerrit Voordouw, a professor and Natural Sciences and Engineering Research Council of Canada industrial research chair in petroleum microbiology at the University of Calgary.
The research indicates that reservoirs should be screened for MEOR, and a range of factors weighed first before deciding to go ahead with it. Still, MEOR could potentially have broad application across the global petroleum sector, resulting in billions of barrels of incremental production.
For oil companies, one part of the allure of successful MEOR – when it actually happens – is that it entails either negligible or no capital investment. It can usually rely almost entirely on existing infrastructure.
CUSTOMIsED NUTRIENTS
Some big chemical companies also appear to be taking MEOR seriously. In September, after a year or two of generalised optimism in the MEOR sector amidst what one expert called a proliferation of green shoots, and just ahead of the winter drilling season, DuPont unveiled its MATRx technology.
According to an announcement from DuPont Sustainable Solutions, the low-capital EOR technology, designed for fields under waterflood, “is distinguished from other microbial enhanced oil recovery technologies with a unique inoculation step.”
DuPont’s MATRx system uses customised nutrients to feed favoured microbes in the reservoir. “The DuPont proprietary injection system protocol ensures that nutrient effects are propagated far beyond the wellbore to prevent wellbore fouling. By moving nutrient effects deep into the reservoir, MATRx can effectively release more trapped oil from deep within the reservoir formation,” according to a DuPont press release.
The targeted proliferation of selected downhole microbes is central to the MATRx concept and DuPont’s MEOR process was operating commercially in Canada for several months prior to its October unveiling. It is perhaps not so surprising that big outfits like DuPont are rolling out new products for MEOR or that the sector has been buoyed up as of late. “Microbiology know-how for isolating and identifying has improved a lot. We can now do things much faster, as in genomics technologies, which are helping,” says John Fisher, business development manager at DuPont Canada and a co-author of several papers on MEOR.
As these technologies mature, companies, it seems, are warming up to the prospect of a giant bioreactor in the ground, which yields incremental crude oil when the appropriate microbial treatments and technologies are applied.
