Hilcorp Energy Co. continues to investigate the cause of a Dec. 21 freshwater spill that occurred on a drilling site in rural El Paso County east of Colorado Springs.
The spill involved two tanks that held a total of 75,000 barrels, or about 3.15 million gallons, of water, said Diana May, the county’s liaison to the Colorado Oil and Gas Conservation Commission. Hilcorp stated previously that the spill released about 1.8 million gallons of water.
May said no one was hurt in the spill and there was no damage to property. Still, she said, “we are obviously concerned with any failure of any system at any oil site.”
The two storage tanks were built in close proximity to each other, with the first located on higher ground. Investigators have determined that water rushing from the first tank caused the walls of the second tank to collapse, adding to the spill. But it’s not yet known why the first water tank failed, May said.
“The release of groundwater was, as best we can determine at this time, a sudden release,” wrote Justin Furnace, spokesman for Hilcorp, in an e-mail to The Gazette.
Hilcorp does not own the two freshwater tanks, Furnace wrote. He did not answer who does own the tanks, who supplies the water stored in the tanks or other questions asked by The Gazette.
The tanks used to store fresh water are called “muscle tanks,” May said. The walls are made of interlocking plastic about a foot thick, she said, and the tanks have a plastic liner similar to an above ground swimming pool. The water held in such tanks is is used in hydraulic fracturing, or fracking, a controversial process used to retrieve petroleum products. Fracking forces a mixture of water, sand and chemicals into a well under high pressure to unlock oil and gas deposits trapped in tight rock formations. Hilcorp and Ultra Resources, which is drilling two wells in eastern El Paso County, are targeting the Niobrara shale formation roughly a mile beneath the surface.
Hilcorp began drilling at the site, known as the Myers site, in late November; it had drilled a total of 6,300 vertical feet and nearly 3,000 feet horizontally at the time of the spill. May said Hilcorp likely won’t begin fracking at the site until late January.
Houston-based Hilcorp has collected base-line samples from the spill site to test for any possible contamination, May said. But she said she did not expect samples to show any contamination because the spilled water had yet to be mixed with any chemicals, the drilling rig was removed and the drilling hole was plugged. Also, the water stored in the type of tank that failed is always pre-fracking water, May said.
“Any processed water, or water used from drilling, is put in a closed metal container,” she said.
Contact Ned Hunter: 636-0275.