Energy and Environment Reporting for Texas

Industry Looks for Safer Ways to Drill with Acid

Trucks at a state-authorized disposal site in Frio County, Texas

Dave Fehling / StateImpact Texas

Trucks at a state-authorized disposal site in Frio County, Texas

Acids used for drilling oil and gas wells are safe according to the oil and gas industry, but companies have been looking for better alternatives to protect workers and the environment.

The concern over acids was highlighted this week in Pennsylvania, where there’s been a boom in drilling for natural gas. The state’s Department of Environmental Protection said it found that Halliburton Energy Services had for years failed to handle hydrochloric acid as a hazardous waste when it trucked it to an unauthorized disposal site. The state said the “acidic waste” had come from “various gas well sites.”

In an agreement with the state announced Tuesday, Halliburton agreed to pay a $1.8 million fine. The state said despite the violations, there was no harm done to people or the environment.

“Difficult to Handle Safely”

Hydrochloric and other acids are commonly used in drilling operations to dissolve rock as a well is drilled. Depending on how the acids are used, some processes are called acidizing when done at low pressure, while using acids at high pressure can be called acid fracturing.

The industry has said using acid is a decades-old technique that is “safe and well-understood.” Nonetheless, a review by StateImpact Texas of industry reports as well as interviews with industry experts show that for years there’s been interest in finding alternatives.

Reports and articles by industry researchers said hydrochloric acid was among acids that were “difficult to handle safely” and that the prospect of stricter government regulation, particularly in Europe, had increased the need for drilling chemicals that offered “reduced environmental and safety risks.”

There seemed to be a promising option, at least for some deeper wells with higher temperatures (wells at depths of 10,000 feet in some shale formations in South and East Texas can exceed 300 F). Mixtures involving less corrosive acids called chelants that worked in these hot wells were “much less toxic to mammal as well as to aquatic organisms.”

Safer but Expensive

But there was the matter of money: the alternative chemicals were “ten times as expensive,” according to one industry researcher. He didn’t want to be quoted by name, but told StateImpact Texas that some drilling services companies were “trying hard to find the most environmentally safe and cost effective” alternatives to the relatively cheap — but less safe — hydrochloric acid.

At the University of Texas, Tad Patzek, chairman of the Department of Petroleum Engineering, said that when it comes to using acids at drill sites, the biggest concern is worker safety.

“Human injuries, that would be the main danger of such a job,” Patzek told StateImpact Texas.

He downplayed environmental risks, at least when talking about what the acids might do after they’re injected into a well.

“These acids react immediately with the rock that surrounds them and are spent within minutes. So I think what the public needs to understand is whatever you do, that acid will be completely exhausted, used up by the minerals within the rock in minutes.” said Patzek. “So no, I don’t lose any sleep over acids working their way through the formation down there.”


  • EyesOfTX

    Yet another non-story on this subject.
    Yes, the industry is looking for safer ways and products to use in conducting its business. Guess what? That has always been the case in this industry since its inception more than 160 years ago. Do NPR reporters simply bring no historical base of knowledge to their jobs?
    As I asked in a comment to the last non-story you filed on this subject: If acid jobs are a problem in this state, where are the real, tangible stories and complaints about it? I mean, of course, from someone other than the anti-fossil fuel activists this reporter apparently obtains his story lines from.
    Still waiting to see a shred of real information indicating there is a real problem – or a real ‘news’ story – related to any of this.

    • CometX_in_NY

      It may not be news to you but it sure is news to me. I own a farm in Pennsylvania. There is an EXCO drilling pad 500 yards from my farm house, so I thought that I’m up to date on fracking technology issues. This article is news to me because I’ve never heard of HCl acid being used in drilling, and I am dumbfounded that EXCO might haul in trucks full of the stuff. Their well goes right through my water table…

    • Mr Mish

      Everyone asleep knows that that fracking industry is perfectly safe. Contamined drinking water is purely in people’s imaginations. It never happened, according to authorities. Explosive water – not proven yet. There’s no aquifer contamination. Earthquakes are not caused by disposing spent fracking fluid into wells – doesn’t matter that this never happened before fracking began. The fracking industry does not control politicians. What’s the matter with you un-American jerks?

  • Mr Mish

    Everything the fracking industry does is safe. The Railroad Commission assures us.

  • TomTX

    Hydrochloric acid really isn’t a long-term concern. Yes, it’s a strong acid that can burn you when it is highly concentrated. At moderate concentrations – it’s what is in your stomach right now. It reacts easily with lots of rock and soil – and when it does, the reaction products are just chlorides, as you find in table salt (admittedly more likely calcium chloride than sodium chloride)

About StateImpact

StateImpact seeks to inform and engage local communities with broadcast and online news focused on how state government decisions affect your lives.
Learn More »