Vamegh Rasouli embraces the term “unconventional” when it comes to North Dakota and the economic promise that it holds.
For most, the word suggests a deviation from the norm, a flirtation with the unknown. For Rasouli, that’s the whole idea.
You see, Rasouli, the Continental Resources Distinguished Professor of Petroleum Engineering and chair of the department at the University of North Dakota, arguably has one of the most important jobs in the state. That is, he’s figuring out how oil companies can extract more oil from deep within the rocky layers of North Dakota’s subsurface — and do it more cheaply.
This is especially important in a cyclical industry, such as oil and gas production, in which prices can fluctuate, greatly impacting companies’ bottom lines and their appetites for further development. This has a ripple effect — good or bad — on the economic well-being of states like North Dakota, which contains the second-largest source of oil in the United States.
The problem is that North Dakota’s oil reserves, though abundant, are of the unconventional variety. There’s that word again.
You’ve heard the idiom squeezing blood from a turnip. Rasouli explains that coaxing oil from the nanoscale pores in shale rock, 10,000 feet under the surface of North Dakota’s western oil fields, is almost as difficult.
“This rock is similar to a very tight sponge with many invisible holes,” Rasouli said. “It does not provide an easy path for the oil to move inside the rock and toward the well bore (passage to the surface). The oil reserves in such tight rocks are known as unconventional reservoirs for which special treatment and technology are required to produce oil.
“The permeability (ability to move fluids inside rock) of unconventional oil and gas-bearing rocks is lower than concrete.”
When times are good, oil companies have ridden the successes derived from hydraulic fracturing, creating a long breach into the shale rock, to expose and extract more oil.
“In low oil-price markets, operators are unwilling to drill new wells due to high costs; therefore, operation of new hydraulic fractures is not possible,” Rasouli said.
That’s why, with the current state of the oil economy, companies have turned to so-called smart technology to drive costs down and make production more feasible even when per-barrel prices dip.
Supported by a $60,000 research grant from UND’s Post-doctoral Funding Program, Rasouli is studying the effectiveness of a concept known as re-fracturing. This is a technique used in conjunction with hydraulic fracturing. It’s a second process that enables further enhancement of an existing fracture at greatly reduced cost, Rasouli explains.
“The re-fracturing technology is very new and needs extensive studies and investigation,” Rasouli said. “This is the main objective of my research project.”
Rasouli is collaborating with the UND Institute for Energy Studies, which is providing some technical input for the project as well as co-advisors for graduate-level students involved in the research. Other partners include local oil industry contractors that are allowing access to field data and other information important for the research.
“While the U.S. (and especially North Dakota) is leading the production of oil from unconventional oil plays,” Rasouli says, “this technology will certainly be used in other fields and other countries, such as China, Algeria and Argentina, which have just started to develop unconventional reservoirs.”
Rasouli has been a consulting engineer for Houston-based Schlumberger Service Company in the past and is now serving as an instructor for that company’s NExT (Network of Excellence in Training) program. The NExT program delivers short courses worldwide in subjects that include petroleum geomechanics, drilling, hydraulic fracturing, pore pressure estimation, and sand control.
By David Dodds