Montana Tech engineers explore EOR options

By Emily Aasand | June 24, 2014

Members of the Montana Tech Petroleum Engineering Department are conducting a pilot project to assess Enhanced Oil Recovery options for the Elm Coulee oil field in Eastern Montana. 

Conventional horizontal drilling and production methods in Montana’s Bakken oil field extract 9 to 15 percent of available oil, the remainder goes untouched.

Funded by the Montana Department of Natural Resources and Conservation, through the Montana Board of Oil and Gas Conservation, the plan involves restoring underground pressure in and around depleted wells to the level that existed when the wells were first drilled. The pilot project will inject either CO2 or natural gas into the shale surrounding the original wells to try to get the unrecovered oil to break free from the rock.

The research team consists of four members, Leo Heath, John Evans, David Reichhardt and Burt Todd.

“We’re trying to take some conventional technologies, apply them to these unconventional reservoirs and see if we can’t improve recovery factors,” said Burt Todd, assistant professor of Petroleum Engineering.

The team has a five-year grant and they’re two and a half years into the research effort.

“There are some phases to this,” said Todd. “Until now, we’ve developed a data base that stores well information for all of Elm Coulee. We’ve built some reservoir simulation models to see what happens when you inject carbon dioxide and what happens when you inject produced natural gas. We’re trying various recovering strategies in the simulation world to see which ones have the most promise.”

Todd and his team are very optimistic that carbon dioxide or produced natural gas will be effective in increased recovery.

“In the Bakken, water flooding probably won’t work because the rock is too tight and the water viscosity is too high, so we’re injecting enhanced oil recovery fluids like carbon dioxide or natural gas,” said Todd. “This method acts a lot like water flooding except that we’re using a much lower viscosity fluid.”

The University of North Dakota’s Energy and Environmental Research Center has done similar work with enhanced oil recovery, but unlike UND, the Montana Tech Petroleum Engineering Department is solely focusing on the Bakken in Eastern Montana.

“The Bakken behaves differently on the North Dakota side than it does on the Montana side,” said Todd. “The general thinking is that the Bakken on the North Dakota side is more fractured. The Montana side in very general terms is not very fractured. You have some good wells, but it tends to be a little thinner.”

According to Todd, the hope is that the less fractured, thinner Elm Coulee might perform better under enhanced oil recovery.

Although the team is still in the research phase, they hope to propose a pilot project by the end of the year.

“We have some good relationships with several of the operators out there who are really interested in our work,” said Todd. “We feel like people have been interested in our work and that there’s a lot of different people waiting to see how this comes out.”