R649-3-12. Drilling Practices for Hydrogen Sulfide H2S Areas and Formations

1. This rule shall apply to drilling, redrilling, deepening, or plugging back operations in areas where the formations to be penetrated are known to contain or are expected to contain H₂S in excess of 20 ppm and to areas where the presence or absence thereof is unknown.

2. A written contingency plan, providing details of actions to be taken to alert and protect operating personnel and members of the public in the event of an accidental release of H₂S gas shall be submitted to the division as part of the initial APD for a well or as a sundry notice.

3. All proposed drill site locations shall be planned to obtain the maximum safety benefits consistent with the rig configuration, terrain, prevailing winds, etc.

3.1. The drilling rig shall, where possible, be situated so that prevailing winds blow across the rig in a direction toward the reserve pit and away from escape routes.

3.2. On-site trailers shall be located to allow reasonably safe distances from both the well and the outlet of the flare line.

4. At least two cleared areas shall be designated as crew briefing or safety areas.

4.1. Both areas shall be located at least 200 feet from the well, with at least one area located generally upwind from the well.

5. Protective equipment shall be provided by the operator or its drilling contractor for operating personnel and shall include the following:

5.1. An adequate number of positive pressure type self-contained breathing apparatus to allow all personnel normally involved on a drilling location immediate access to such equipment, with a minimum of one working apparatus available for the immediate use of each rig hand in emergencies.

5.2. Chalk boards or note pads to be used for communication when wearing protective breathing apparatus.

5.3. First aid supplies.

5.4. One resuscitator complete with medical oxygen.

5.5. A litter or stretcher.

5.6. Harnesses and lifelines.

5.7. A telephone, radio, mobile phone, or other communication device that provides emergency two-way communication from a safe area near the well location.

6. Each drill site shall have an H₂S detection and monitoring system that activates audible and visible alarms when the concentration of H₂S reaches the threshold limit of 20 ppm in air. This equipment shall have a rapid response time and be capable of sensing a minimum of ten ppm H₂S in air, with at least three sensing points, located at the shale shaker, on the derrick floor, and in the cellar. Other sensing points shall be located at other critical areas where H₂S might accumulate. Portable H₂S detection equipment capable of sensing an H₂S concentration of 20 ppm shall be available for all working personnel and shall be equipped with an audible warning signal.

7. Equipment to indicate wind direction at all times shall be installed at prominent locations. At least two wind socks or streamers shall be located at separate elevations at the well location and shall be easily visible from all areas of the location. Windsocks or streamers shall be located in illuminated areas for night operations.

8. When H₂S is encountered during drilling, well marked, highly visible warning signs shall be displayed at the rig and along all access routes to the well location.

8.1. The signs shall warn of the presence of H₂S and shall prohibit approach to the well location when red flags are displayed.

8.2. Red flags shall be displayed when H₂S is present in concentrations greater than 20 ppm in air as measured on the equipment required under R649-3-12-6.

9. Unless adequate natural ventilation is present, portable fans or ventilation equipment shall be located in work areas to disperse H₂S when it is encountered.

10. A flare system shall be utilized to safely gather and burn H₂S bearing gas.

10.1. Flare lines shall be located as far from the operating site as feasible and shall be located in a manner to compensate for wind changes.

10.2. The outlets of all flare lines shall be located at least 150 feet from the well head unless otherwise approved by the division.

11. Sufficient quantities of additives shall be maintained on location to add to the mud system to scavenge or neutralize H₂S.