Caelus plans fracking technology with a twist
When Caelus Energy begins development of its Nuna project on the North Slope it will employ technologies borrowed from the Lower 48 shale oil industry, but with a twist.
The company plans to use large-scale hydraulic fracturing on its oil production wells, though not to the degree used in the North Dakota Bakken and the Texas Eagleford shale producing regions.
The new twist is that injection wells will be fractured, too. Nuna will be producing from a tight-rock formation known as the Torok which has not previously supported commercial production, state officials have said.
Fracturing with high-pressure liquids will break open the tight rock to let oil flow, but the fracture on the injection wells will allow fluids to be injected and to circulate, to push oil in the reservoir.
Fluid injection, mostly water, is commonly used on the North Slope to push oil in the porous underground reservoirs toward production wells. The fracturing will enable the process to work in the tighter rock, however.
Caelus’ experiments with the process and how well it works will be published, with technical information made available to the public under an agreement between the company and the state Division of Oil and Gas. That will allow other companies to benefit from Caelus’ experience with the process.
The provision is part of Caelus’ agreement with the state for a temporary reduction of state royalty from 12.5 percent to 5 percent.
Pioneer Natural Resources, Caelus’ predecessor at Nuna and the nearby Oooguruk field, which Caelus also purchased last year when it bought Nuna, tested the large-scale fracturing early last year on four new Oooguruk production wells.
“We were very pleased with the results,” in production, compared to what the wells would have produced without the fracturing, said Caelus spokesman Casey Sullivan.
About 2 million pounds of proppant material were used in the fracturing jobs, about a third of what is often used in very large Lower 48 fracturing, he said.
While the Oooguruk fractures were done in a different producing reservoir than those to be done at Nuna, the Nuiqsut formation, Pioneer also tested the procedure on one of the two evaluation wells drilled at Nuna where production tests were done.
That test showed the procedure also worked in the Torok formation.
State officials said new technologies that can be applied to the Torok are important because the formation is widespread across the west-central North Slope, and with a great deal of potential recoverable oil.