A recently hydraulically fractured horizontal oil and gas well was drilled within about 400 feet underground, and possibly within 260 feet, of a nonproducing well discovered to be leaking Saturday. The inactive, 32-year-old vertical well showed no leaking or structural problems during a routine Bureau of Land Management inspection July 9.
Authorities are continuing to investigate the cause of the newly discovered leak at the Maralex Resources well on BLM-managed land on Jaw Ridge in Mesa County about seven miles southwest of De Beque. One possibility is that hydraulic fracturing of a horizontal well owned by another company, Black Hills Exploration & Production, may be responsible.
The BLM and Colorado Oil and Gas Conservation Commission are investigating the incident with the assistance of both companies. BLM spokesman Chris Joyner said the COGCC took soil and water samples Tuesday.
“We’re being told within a week we’ll know what the analysis shows,” he said.
“If it’s fracking fluids, then obviously that will give us an indication that it was related to the other site that was recently fracked,” Joyner said.
Joyner said the BLM is being told a citizen, possibly a hunter, discovered the leak Saturday. The leak was bubbling up from around the well, but Maralex opened the well to divert the leak to a holding pit, which caused the water and gas to come up only through the well and suggested the action relieved the pressure, he said.
Todd Hartman, spokesman for the Colorado Department of Natural Resources, said late Tuesday afternoon that it appeared the flow of fluids and gas had stopped altogether. An unknown amount of fluids initially migrated off the pad but didn’t reach surface water, Joyner said.
Maralex “acted quickly Saturday and got it going into a containment pit. That helped a lot,” he said.
A containment berm around the pad was built Tuesday.
Joyner said Maralex removed 160 barrels of fluids from the pit, which had been dry during this summer’s inspection. He said precipitation likely accounts for part of that amount.
The leaking well is 7,300 feet deep and about a mile southeast of a 6,000-foot-deep Black Hills well that Joyner was told was fracked within the last 10 days. He said the leak appears fairly fresh, or the volume would likely be much larger.
Maralex couldn’t be reached for comment. Black Hills spokesman Wes Ashton said his company’s horizontal well went underground within about 400 feet of the Maralex well. Joyner said that’s possible, but it could have come within 260 feet. Joyner didn’t know how close to the well it was allowed to be, and Ashton didn’t know how far the fractures from the Black Hills well were expected to extend.
Ashton said Black Hills has drilled four wells, all horizontal, in the De Beque area in the last three years.
“We’ve got a pretty good track record and history in the local area. … We’re just doing anything we can at this point to assist what’s going on and as far as the review.”
Horizontal drilling, which involves drilling down and then out 90 degrees sometimes for long distances, is becoming increasingly popular, in Colorado’s case mostly in northeastern Colorado where companies are pursuing oil development.
Path to surface
Bruce Baizel, energy program director with the Earthworks conservation group, said such drilling poses a challenge as the wells “wiggle and waggle” between pre-existing vertical wells, at closer and closer distances with less margin for error. Especially if the wells are older, perhaps with corroded pipe or with cement sealing around them that has weakened over time, there’s the potential for leaks when high-pressure fracking occurs, he said.
“You put pressure on it and boom, there goes your crumbling cement and you’ve got a path right to the surface,” he said.
Ashton said Black Hills does collision-avoidance studies, including resurveying of existing wells and planning of a well path to avoid existing well bores.
“This is an issue of concern to the industry and operators in the industry are presently working with regulatory agencies to address the issue and we’re actively participating in that process,” he said.