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The hills have kaolinite: Geological Survey studys clay in western counties

Press Photo by April Baumgarten The North Dakota Geological Survey studied kaolinite clay samples this fall in the Dickinson area to see if it could be used for keeping hydraulic fractures open.

North Dakota officials are looking at local resources to keep fractures for oil wells open and meet a proppant shortage, officials said.

The North Dakota Geological Survey in Bismarck has completed collecting kaolinite samples from 10 counties in the west, including Stark, Dunn and Morton counties, according to its news publication.

"We looked at the ceramic proppant that was being used in the Williston Basin and saw it was coming in from out of state," state geologist Ed Murphy said, adding most of it comes from out of the country, including China and Russia.

Proppant is used to keep fractures open in hydraulic fracturing, or "fracking." Kaolinite sometimes has high aluminum properties, which is one of the main ingredients for proppant, Murphy said.

Kaolinite can be dazzling white, gold, purple or gray in color and can range from claystone to sandstone. Deposits are usually 10 feet to 40 feet thick and can be seen in hillsides.

"We have kaolinite in North Dakota," he said. "We went out this fall and ... we collected more samples than we thought. We got pretty good coverage."

Murphy and his team collected 231 clay samples from 61 sites as of January, which were sent to the North Dakota State University Center for Nanoscale Science and Engineering last week. He did not specify how many samples were sent in.

The samples come from two formations -- the Bear Den Member of the Golden Valley Formation, which is mostly concentrated across Mercer, Stark and Dunn counties, and the Rhame Bed of the Slope Formation, which starts in southern Golden Valley County, dips across Slope, Bowman, Adams and Grant counties, and climbs north into central Morton County.

The Geological Survey also did a study on sand to see if it could be used. It collected 125 samples and sent in 10 in the fall. The samples approached industry standards, but the quality was less than what was being used, Murphy said.

"Companies might be able to further process those sand deposits, which has additional costs," he said. "I would think in most cases it would be cheaper to bring in sand that fits those criteria from out of state."

If the study turns out positive results, it could mean a supply at home, which would close the gap between starting a fracture and getting the proppant, said Monte Besler, owner of Williston-based FRACN8R Consulting.

"We would have a supply which we wouldn't necessarily have to ship from wherever," he said. "It would be a huge economic boom for North Dakota (if it was proven)."

Murphy said the results should come back late spring. He speculated that the Bear Den will produce higher quality kaolinite, but the results will have the final say.