Researchers Hope Bugs Speed Methane Take
BILLINGS, Mont. Researchers are studying whether microbes can be manipulated by science to expand the life of coal-bed methane wells in the Powder River Basin of Montana and Wyoming.
So far, results look "very promising," said Seth Snyder, a researcher at Argonne National Laboratory. Argonne, located 25 miles southwest of Chicago, is one of the U.S. Department of Energy's largest research centers.
Argonne and researchers at the Montana Bureau of Mines and Geology have been studying whether microscopic bacteria that naturally break down organic materials to create methane can be encouraged to produce the natural gas faster and for an extended period.
Snyder's team has done initial work on coal from the region and tested its chemical theories on microbes in sewage sludge.
"It definitely looks like they're accelerating methane production," he said.
Now it's time to try those theories on actual microbes or "bugs" from a coal-bed methane well.
John Wheaton, a hydrogeologist, and Jay Gunderson, a coal geologist, both with the Montana Bureau of Mines and Geology, recently collected microbe samples for Argonne from wells being drilled by Nance Petroleum Corp. on a ranch in northern Wyoming.
Grabbing microbe samples requires patience and timing. The Montana scientists studied well logs from area wells.
"We're trying to figure out when to expect the next coal beds based on what we already know about recent drilling in this area," Gunderson said.
Gunderson held a strainer under the rig's discharge pipe to catch drill cuttings and mud and examined the sample for coal.
Gunderson and Wheaton also checked piles of cuttings plopped in rows on the ground by the drillers. The piles are samples taken about every 10 feet and track the depth of the drill and what it is cutting. Shale layers are gray, while coal layers are black.
Pointing to the piles, Wheaton said, "The bugs in this would be damaged if not dead by now sitting out here in the air and sun, so that's why we have to make sure we get fresh samples right out of the line."
Because the microbes live in an anaerobic environment -- one without oxygen -- exposure to air kills them.
The microbes, Gunderson said, are tiny bacteria that chew up the coal or anything else with carbon in it and produce the methane. Making methane is "actually a complex reaction in multiple steps by a whole community of those little microbes," he said.
In all, the scientists collected 16 one-liter samples from two coal seams. The samples were shipped to Argonne last week.
Argonne is studying the biology and the water chemistry of the microbes and theories by Ratin Datta, the lab's chemical engineer, Snyder said. Understanding the chemistry and physical conditions of the microbial community is key to determining the right conditions to help the microbes become rapid producers of methane, he said.
Coal-bed methane in the Powder River Basin is found in coal seams and dates back 60 million years. Mining for the methane requires drilling a series of wells into coal seams and depressurizing the aquifer by pumping ground water to the surface. The life of a coal-bed methane well can vary, but some estimates are 20 years for wells in the Powder River Basin.
Argonne and other laboratories are trying to find ways to enhance the microbes. Based on the large volume of coal in the basin, enhancing microbes could extend methane production by several hundred years according to some estimates, Snyder said.
Argonne is working on proving its concept and is planning to file for a patent this year, Snyder said. This stage of the research is costing about $50,000. The next phase would cost several million dollars and involve working with partners, he said.
Source: Associated Press