Horizontal hydraulic fracturing for oil is running into old-style oil wells and damaging them

A hydraulically fractured oil well near Stillwater, Oklahoma
(Photo by J. Pat Carter, Getty Images)

Supersized new oil wells are sometimes running into existing wells, a little-noticed consequence of the shale-oil boom that has triggered complaints and lawsuits, reports Erin Ailworth of The Wall Street Journal.

The emerging problem is known as a "frack hit," and it's popped up in Oklahoma, where a group of small oil and gas producers say more than 100 of their wells have been damaged by hydraulic-fracturing jobs done for larger companies, Ailworth reports.

"In hydraulic fracturing, or 'fracking,' firms pump sand and water deep underground at high pressure to break oil and gas from rock," Ailworth explains. "Some owners of older wells have filed reports with state regulators claiming their wells were flooded with water. In some cases, the wells became so full that the water rose to the surface and spilled over. Others have claimed that they had to shut in wells due to the damage. A few cases have ended up in court. While newer wells damaging older ones is a longstanding problem, the issue is gaining attention as shale companies employ new technologies to drill wells horizontally."

In Oklahoma, companies aren’t required to report frack hits unless there is a spill. "Regulators there have received fewer than 20 confirmed reports of such incidents in the last three years and are currently reviewing several more," Ailworth writes. "Oklahoma last month passed a bill that eases restrictions on where producers can drill horizontal wells more than a mile long. Vertical-well operators now worry their wells are more vulnerable than before."

Chad Warmington, president of the Oklahoma Oil & Gas Association, questioned allegations that hundreds of wells have been damaged. In some cases, he argued, frack hits can actually boost production from an affected well. "But given the potential for damage, the association supports making reporting frack hits mandatory, Mr. Warmington said, and would be open to having a mediation or arbitration process put in place. Some experts expect the situation will only get worse," Ailworth writes.

"We’ve got bigger fracks, so more chance of them reaching across, well-to-well," Jennifer Miskimins, an associate professor of petroleum engineering at the Colorado School of Mines, told Ailworth. "As we get closer and closer spacing, I think we’re going to see the occurrence go up."