Hydrogen Sulfide: Responsibilities and Duties of Personnel

Depending on the rig’s emergency plan for an H₂S release, crew personnel should follow their predetermined instructions. For example, in the event of a blowout or H₂S encounter, the driller, derrickman and motorman will put on gas masks. One floorman will notify the toolpusher and company officials. The other floorman will retire to the predetermined muster site, a safe distance from the well on the windward side. The men equipped with gas masks will close all blowout preventers or valves on the casing head.

It is the responsibility of all people on the rig to familiarize themselves with the procedures outlined in the Operators’ Contingency Plan.
Each individual will be responsible for assigned safety equipment.
Crew members should help anyone who may be injured or overcome by toxic gases. Always put on self-contained breathing apparatus (SCBA) before going to assist anyone affected by H₂S. Speed is important. Be prepared to act quickly.
When the alarm is sounded, go to the designated Safe Briefing Area.
Report any indications of H₂S to those in the area and to your supervisor.

Respiratory Protection

All personnel whose presence is required on a drilling location where H₂S is suspected, will have certified breathing apparatus available to them. Each person must determine his own duration for air consumption from the air pack. Many factors can greatly reduce the rated duration. The person’s size, physical condition, breathing habits, etc., must be considered.

Special Problems in Respirator Use

Facial hair between the respirator face‑piece sealing surface and the skin will prevent an effective seal.
Contact lenses should not be worn while wearing a respirator in a contaminated atmosphere.
Corrective glasses with temple bars or straps that interfere with the respirator face seal may not be used because they will permit excessive contaminant penetration.
While wearing an SCBA, an employee’s breathing is more difficult, sight is somewhat restricted, movement and voice communication may be restricted or lacking. Training and familiarization drills will help minimize most of these discomforts.

Safety Reminders

The best line of defense against H₂S is to follow good drilling practices and good well control procedures.
Use detection equipment when working in an area where there is a possibility of H₂ This equipment must be maintained and calibrated as per the manufacturer’s specifications.
H₂S is heavier than air; therefore avoid low-lying areas.
Smoking is prohibited in close proximity to the source of the explosive gas. Smoking will be allowed only in designated areas upwind and away from the rig and equipment.
H₂S and SO₂ are heavier than air and will settle to the ground or water surface in calm wind conditions. Do not jump in the water!
Employees required to wear respirators may not wear beards, sideburns or caps or glasses, which project under the rim of the face piece. Such obstructions in the face‑to mask seal permit air to leak out of the mask. Air leakage causes rapid depletion of the air supply.
When under H₂S conditions, an employee must go immediately to an area having respirable air if his breathing apparatus fails to provide proper protection.
All employees should report any breathing equipment malfunctions to their supervisors.
All individuals must know how to operate all lifesaving and other H₂S emergency equipment on location.
Plan a minimum of two escape routes from where you are working.
Select a partner and use the “Buddy System”.
Continue to monitor wind direction throughout your work tour by observing windsocks, flags and sea conditions.
Observe “Condition” signs and observe audio/visual alarms for changes.
Breathing apparatus and other safety gear should be positioned upwind of the wellbore and should be capable of being moved in case wind direction shifts.
Recharge breathing apparatus after use in emergency drills. Get back to ready status conditions.
Never attempt to rescue someone without first putting on an SCBA.