Research led by the University of Alaska Fairbanks on viscous oil recovery using polymer injection at the Milne Point field on Alaska’s North Slope has resulted in a tripling of production from some Schrader Bluff formation wells.
As field operator Hilcorp Alaska implements polymer injection on more and more drilling pads, the University of Alaska Fairbanks Institute for Northern Engineering’s Petroleum Development Lab is moving on to tackle methods for recovery of the even heavier oil found in the shallower Ugnu formation.
In an Oct. 7 press release, the governor’s office said UAF engineers and Hilcorp have been successful in using polymer flood for enhanced oil recovery at Milne Point, using a mixture of polymer and seawater.
The initial research was supported by federal funds, but the state has now stepped in to support new research.
Initial projectThe polymer injection research, with funding from the U.S. Department of Energy beginning in 2018, was in conjunction with DOE, the National Energy Technology Laboratory and Milne Point operator Hilcorp Alaska. The objective was to demonstrate the value of polymer in enhanced oil recovery in the arctic environment.
At an Oct. 7 press conference at UAF, Gov. Mike Dunleavy said since DOE is not funding further heavy oil research, the state has committed $5 million in the FY 23 state budget for work to find a way to produce the heavier oil in the Ugnu formation.
Hilcorp using polymer injectionJill Fisk, a Hilcorp vice president and one of the company’s Prudhoe Bay managers, said with the success of the polymer injection project for viscous oil - such as that found in the Schrader Bluff formation in Hilcorp’s Milne Point field - the company has expanded use of the technology. It is now employed on seven Milne Point pads, with injection into more than 30 wells - and Hilcorp is continuing to expand the project.
Fisk said polymer flood can triple production: Milne Schrader Bluff wells without polymer injection averaged some 300 barrels per day and with polymer are averaging some 900 bpd.
She said the company demonstrated that polymer can be shipped in bulk to the North Slope, can be mixed with water in arctic conditions and requires less than 2 pounds of polymer per extra barrel, which, Fisk said, is the best result in the industry.
Ugnu is the next opportunity, with research and development expected to take years as wells are drilled and produced and improvements made in the process. Great partners, UAF and the state, are crucial to success, she said, with Ugnu opportunities existing in both Milne Point and Prudhoe Bay.
UAF’s roleAbhijit Dandekar, professor and chair of petroleum engineering at the UAF College of Engineering and Mining, summarized success of the work done to date by UAF.
He said funding available beginning in 2018 enabled UAF, working with the U.S. Department of Energy, the National Energy Technology Laboratory and Hilcorp Alaska, to demonstrate the value of polymer in enhanced oil recovery in the arctic environment.
With the polymer injection project completed, Dr. Yin Zhang will be the principal investigator in the next phase, using polymer alternating solvent, PAS to target even heavier oils, Dandekar said.
He said viscous oils are water or polymer solution floodable, while heavier Ugnu oil is not, requiring the use of a solvent first to reduce viscosity of the Ugnu oil, the goal of polymer alternating solvent, PAS.
Viscous and heavy oil represents about a third of known North Slope original oil in place, with cumulative production of those resources to date about 1%, Dandekar said.
In addition to the large resource and existing infrastructure, research now is important while lighter North Slope oils are being transported through the trans-Alaska oil pipeline, and available to act as a diluent for the heavy oils.
- KRISTEN NELSON