H₂S EMERGENCY CONDITION

When an H₂S Emergency (>50 ppm) condition has been called by the offshore installation manager, implement the following procedure:

1. All rig floor personnel put on BAs and remain on the rig floor unless otherwise instructed by the offshore installation manager.
2. All drilling/coring operations stop and the driller makes the string back up (if open), picks up off bottom, and maintains circulation.
3. The offshore installation manager notifies the ship's officers and operations manager of the situation.
4. The ship's officers sound the alarm using coded bell signals and verbally announce to all personnel via the public address system that an H₂S EMERGENCY exists and to report to a safe-briefing area.
5. The ship's officers shut down the ventilation systems.
6. The ship's officers notify any nearby vessels to go upwind and maintain a radio and visual watch.
7. At the safe briefing the ship's officers (or designees) take roll and account for all ship personnel.
8. The ship's emergency response team, using BAs, make maximum effort to determine the source of the H₂S and suppress the H₂S as quickly as possible.
9. All personnel not assigned to emergency duties or working on the rig floor report to the upwind safe-briefing area for further instructions.
10. Drilling/coring operations remain suspended until the source of H₂S is located and the atmospheric level falls to a level <10 ppm.
11. The buddy system is utilized for all personnel remaining in the potential danger area.
12. The hole may be terminated, depending on the source of the H₂S, by the offshore installation manager.
13. The operations manager notifies the appropriate personnel on shore as soon as possible of the situation and the actions taken.
14. The driller is notified if the exhaust fans in the laboratory stack are turned on to exhaust H₂S because the exhaust fans discharge air above the rig floor.

The primary safe-briefing areas are the port and starboard lifeboat stations located forward on the fo'c'sle deck. The port and starboard lifeboat stations are the safe-briefing areas because when the drillship is in dynamic-positioning (DP) mode, the bow of the ship is nearly always oriented into the prevailing wind.

The routes to the safe-briefing area are determined by the master and reviewed in safety meetings held with personnel working in each area of the ship. The best route from each location on the ship is dictated by rig floor activity, weather, and sea conditions.

All personnel not assigned emergency duties who are aft (i.e., back by the helideck) of the rig floor proceed forward to the safe-briefing stations along the mezzanine or main deck on the windward side of the ship. Personnel must avoid entering areas designated as potential H₂S danger areas as they proceed forward to the safe-briefing areas.

If, for some reason, the stern of the ship is oriented into the wind, the master announces to all ship personnel that the safe-briefing area is the helideck. The location of the designated safe-briefing area is posted by the master or mates next to the ship's station bills (where lifeboat assignments are posted) on each deck.