Washington, April 12 : A scientist from US has found a way in petroleum microbiology to figure out how to squeeze more petroleum out of abandoned or soon-to-be-abandoned oil fields.
Putting more than 40 years into research work, Lewis Brown, a microbiologist at the Mississippi State University, has already managed to extend the life of one field by 17 years.
That it has been possible because Brown's research 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.
According to Brown, 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 said.
Brown had already proved his method long ago 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," said Brown. "This will help give us more time to develop replacements for our major energy source," he added.
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 dollars 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," said Brown.