Hydrochloric acid is commonly using in horizontal drilling because it’s relatively cheap, but companies are looking for safer alternatives to protect workers and the environment reported StateImpact Oklahoma.
Hydrochloric and other acids are commonly used in drilling operations to dissolve rock as a well is drilled. If the acid is used at low pressure the process is called acidizing. If used under high pressure, it is then called acid fracturing.
Industry researches say hydrochloric acid is difficult to handle safely, and the with stricter governmental regulations on the horizon, especially in Europe, the need for chemicals that have reduced environmental and safety risks has increased. One industry researcher, who doesn’t want to be named, says these alternatives are “ten times as expensive.”
Tad Patzek, chairman of the Department of Petroleum Engineering at the University of Texas says he doesn’t worry about environmental safety using hydrochloric acid.
“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.”
His concern is for worker safety.
“Human injuries, that would be the main danger of such a job,” Patzek told StateImpact Texas.