Scientist Seeks Ways To Squeeze More Oil Out Of Existing Wells
Lewis Brown continues to devote much of his more than 40 years in petroleum microbiology figuring out how to squeeze more petroleum out of abandoned or soon-to-be-abandoned oil fields.
The Mississippi State researcher already has extended the life of one field by 17 years. That may sound far-fetched for those unfamiliar with his ongoing research that involves the forced growth of oil-chasing microbes used to redirect injected water that, in turn, sweeps once-inaccessible oil from old wells into production.
Brown said two-thirds of all U.S. oil remains in the ground because it's not economically feasible to remove with existing technology. "We've now developed a method to get some of that oil out of the ground," he added.
The veteran microbiology professor long ago proved his method in a Northwest Alabama field experience sponsored by the U.S. Department of Energy, along with a Jackson-based oil company. The demonstration reinforced what he had discovered in laboratory experiments.
Before Brown began his Alabama experiment, analysts had predicted those wells would stop producing in 1998. After Brown had applied his method, follow-up analysis indicated the wells could still produce--and might continue to do so until 2015.
To date, the Alabama project has recovered more than 400,000 additional barrels. "This process has us talking about potentially recovering much of the now unrecoverable oil," Brown said. "This will help give us more time to develop replacements for our major energy source."
It's no surprise petroleum industry insiders from around the world have been contacting Brown about his research. Through private and public funding, more than $7 million has been devoted to Brown's research related to his oil recovery method. He currently is negotiating with companies from the Middle East to Great Britain interested in applying his process.
Historically, few in the industry had expertise related to microbiology, Brown explained. While much field research had focused since the 1940s on "microbial enhanced oil recovery" --known commonly by the acronym MEOR--few in the industry accepted the associated methodology for fear of plugging the wells. The few trials that were conducted didn't last long enough to determine any long-term effects associated with the process, he explained.
The difference between Brown's method, called microbial permeability profile modification, and most MEOR methods is that Brown only injects plant nutrients. Most MEOR processes involve injecting microorganisms.
By feeding only indigenous microbes in the oil-bearing formations, Brown avoids problems that can plug the wells. While limiting the amount of environmentally friendly nutrients limits their growth, it successfully alters the paths of injected water used to sweep the hiding oil from previously untouched areas.
In addition to being environmentally friendly, the process is cost-effective, Brown observed. In a recent field trial, the additional cost of the process was just $1.32 per barrel of new oil.
Though there are limits to the depths at which microbes can be expected to grow, Brown has been able to isolate microbes at depths of more than 14,000 feet, and some can even grow at temperatures above 100 degrees Celsius.
"This certainly extends the number of oil fields where this methodology could be applied," Brown said proudly.
While Brown continues to work with petroleum industry leaders in removing additional oil from the ground, he has launched a second project in Wyoming to revive depleted natural gas wells located in coal beds. As with the liquid product, he's using indigenous microflora in these wells to produce more methane.
Brown's methods for recovering the oil have earned him accolades from within the petroleum industry and from the federal government. As then-U.S. Secretary of Energy, Bill Richardson (now New Mexico's governor) wrote several years ago to thank him for his contributions after the field process proved successful. Also, the method earned a 1999 "Best of the Gulf Coast" certificate in the advanced recovery project category from the magazine Hart's Oil and Gas World.
Adapted from materials provided by Mississippi State University.