The Pennsylvania Department of Environment Protection (DEP) has written each company drilling into the Marcellus Shale to remind them of proper well construction and emergency notification procedures. Marcellus Shale is a sedimentary rock formation containing largely untapped natural gas reserves. The letters stem from a June 3 natural-gas well blowout in Clearfield County, Pa.

Among other things, the letter stated that:

  • A snubbing unit, which prevents pipes from ejecting uncontrollably from a well, may be used to clean out the composite frac plugs and sand during post-fracturing (post-frac) if coil tubing is not an option.
  • A minimum of two pressure barriers should be in place during all post-frac cleanout operations.
  • Any blowout preventer equipment should be tested immediately after its installation and before its use. Records of these tests should be kept on file at the well site or with the well-site supervisor.
  • A sign with DEP's 24-hour emergency telephone number and local emergency response numbers, including 911 and the county communications center, should be posted prominently at each well site.
  • At least one well-site supervisor who has a current well-control certification from a recognized institution should be on location during post-frac cleanout operations. These certifications should be in well-site supervisors' possession at all times.
  • A remote-controlled, independently powered blowout-preventer unit, which allows workers to control what is happening on the rig at a safe distance from the well, must be operational during all post-frac cleanout operations.

The DEP has promulgated these requirements pursuant to its authority under section 209 of the Pennsylvania Oil and Gas Act.