Making old oil fields new: The Enhanced Oil Recovery Institute
The Osage Field near Newcastle had seen better days when the Sunshine Valley Petroleum Company bought it in 2012. The aging oil field is one of the continually producing fields in Wyoming. Of the some 600 operating oil wells, 200 were producing – and each of those was only managing a meager barrel a day, barely enough to be economical. An oil mining company had recently tried and failed to make the field profitable.
“We got it for a good price because it wasn’t economic to begin with,” said Marron Bingle-Davis, a geologist for the Sunshine Valley subsidiary Osage Partners, LLC. “It’s been hobbling along for a time.”
Sunshine Valley nonetheless saw promise in Osage. (The company operates the field through its subsidiary (Osage Partners, LLC.) The field produced approximately 30 million barrels of oil since its first wells were drilled around 1920. The company estimated that roughly three quarters, or some 95 million barrels of oil, remained locked beneath the surface.
But to access it they would need to try something new. Traditional extraction methods had pumped nearly all they could from the ground. And so Sunshine Valley developed a plan using new technology to access what traditional methods could not.
Still there was a problem. Sunshine Valley operates 2,000 wells across Wyoming and employs around 50 people. ExxonMobil it is not. The company cannot afford the expensive research needed to effectively deploy the new technology that would make Osage profitable.
Enter the Enhanced Oil Recovery Institute (EORI) at the University of Wyoming. EORI was created by the state Legislature in 2004 to help small operators increase production at the state’s mature oil fields. Prying the unrecovered oil from those fields represents a potentially hefty prize. Wyoming has an estimated 15 to 20 billion barrels of untapped oil reserves. EORI’s goal is to recover 1 to 2 billion of those in the coming decades. Put differently, Wyoming’s mature oil fields generally recover 30 to 60 percent of the oil they are estimated to contain.
EORI’s mission is to do the research that will help get the remaining oil out of the ground.
“We do a lot of a research and technical work that they cannot do because it is pricey,” said Laura Dalles, outreach coordinator at EORI, speaking of the state’s smaller producers. “Then we help them take it to the field.”
Oil production can be thought of in three stages. The first stage, generally speaking, involves drilling a well and relying on the pressure within the earth to bring the oil to the surface. The secondary stage mainly involves injecting water into wells to stimulate production. And the third stage involves injecting steam, carbon dioxides, soaps and polymers into a reservoir, essentially cleaning the oil from the rock.
“Oil could stick on rock, like dirty dishes. We have to wash it off like the dishes,” explained Sheena Xie, EORI lab manager.
EORI focuses on the second and third stages.
Many times, the scope of the work in Wyoming’s mature fields is not large enough to justify the investment in a consultant who can help companies’ maximize production, said Vicki Stamp, a reservoir engineer at True Oil who has worked with EORI for years.
By comparison, EORI’s research is a relative bargain. Companies provide the institute with rock samples from the formations they are looking to drill. EORI in turn provides them with information about the rock formation’s characteristics and a series of recommendations on how to recover the remaining oil. That might include everything from an expanded waterflooding plan to fine tuning the chemicals in the waterflood to boost production.
That research helps extend the life of the field, Stamp said.
“Many of these fields were drilled and developed 20, 30, 40, 50 years ago,” Stamp said. “The low hanging fruit has been produced. To get at this additional barrel requires some additional work. It does provide a more hopeful outlook for these fields.”
Her colleague Shane True, a geologist at the Casper-based oil company, described the impact of EORI’s work like this: “Without this research we’d have to plug these fields. We’d have to reassign or let go our staff working in northeast Wyoming.”
In the case of Osage, a century of waterflooding was damaging the rock formation and hindering production. Before Sunshine Valley restarted the waterflood it needed to know the geological characteristics of the formation. EORI did that research for the company. Sunshine Valley is now working with Tiorco, a Denver-based enhanced oil recovery company, and EORI to fine tune the chemicals used in the water flood. Those chemicals include soaps, gels and clay stabilizers to make sure the rock doesn’t swell with water The hope is to recover somewhere between 10 to 15 percent of the 95 million barrels remaining in the field.
Bingle-Davis, the Osage geologists, called EORI’s contribution “essential.”
“These analyses would otherwise not be available to us as a small operator,” Bingle-Davis said. “Essentially we can design the best waterflood possible to recover the most amount of oil without making major mistakes that might hinder the recovery process.”