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Drilling and Operating Oil & Gas and Geothermal Wells in H2S Environments


Quiz Questions

1.H2S is a colorless, acidic gas, almost as toxic as hydrogen cyanide and between 5 and 6 times more toxic than carbon monoxide. H2S gas may be present in crude oil and natural gas produced from oil or gas wells, and in hydrothermal fluids produced from geothermal wells.
True
False
2. Lower concentrations of H,S gas have a sweet taste, and the odor of rotten eggs can be detected.
True
False
3.Upon exposure to higher concentrations of H,S gas (1M ppm or above), the sense of smell is impaired in 2 to 15 minutes due to paralysis of the olfactory nerve (National Safety Council). In addition, death from exposure to still higher concentrations of H2S gas can occur from lung paralysis before any odor is detected.
True
False
4.A well site planned for an H2S environment should be larger than usual, i.e., larger reserve pits, turnaround room, etc. The extra room allows for a greater margin of safety in well site activities.
True
False
5.Ventilation across a drilling a rig site with an H2S environments is not important.
True
False
6.Livestock must be moved out of pastures in hazardous zones before a drill stem test is made. Animals are overcome quickly by poisonous gases.
True
False
7.Two or three, cleared, briefing areas should be designated that are at least 225feet from blowout prevention equipment so they offset prevailing winds perpendicularly (or at a 45" angle if wind direction tends to shift in the area). Self– contained breathing equipment for the crew and on–site personnel should be kept in each of the briefing areas so equipment would not have to be moved with shifts in the wind.

The briefing area most upwind is designated as the "Safe Briefing Area". In an emergency, personnel must assemble At this upwind area for instructions from their supervisor.

True
False
8.Depending on the environment, it is usually safer to burn H2S gas than to let it blow into the atmosphere. Primarily, burning H,S gas produces sulfur dioxide (SO, ). The heat carries the S02 and H2S gases high into the air, mixing them with a greater volume of air, thereby lowering the concentration of the H2S.
True
False
9.Two flare areas should be located 90 degrees from each other. The flare areas should be at least 150 feet from the rig and other installations to protect workers during testing and trouble periods, The ground should be cleared around flare areas to prevent brush and grass fires.
True
False
10.Flow lines and flare lines should be targeted with running tees and staked securely. Flow lines to flare areas should be as long (150 feet, minimum) and as straight as possible, free from 90 degree turns. After installation, flare lines should be tested with air, natural gas, or butane to ensure proper operation.
True
False