Carrizo Oil & Gas temporarily lost control of a Marcellus Shale gas well they were fracking in Wyoming County, PA on Wednesday. The company was in the 23rd stage Wednesday about 6:00 pm when wastewater and brine started to flow at a rate of about 800 gallons per minute—too fast to control. The concern was that natural gas (methane) would start pouring out of the hole too, so Carrizo and a specialty well control crew worked through the night and by early Thursday had the problem contained, and by Thursday afternoon they had the well capped. No methane was released into the atmosphere and the wastewater was contained.
During the episode three families that lived within 1,500 feet of the well were evacuated as a precaution. They returned on Thursday. Here’s the details about the accident as we know them: