SPE Health, Safety, and Environment 3 — Questions and Answers
Question 1: What is the minimum required oxygen concentration for normal work in a confined space according to OSHA standards?
- 16.5%
- 18.5% (19.5% per OSHA) (Correct answer)
- 21.0%
- 23.5%
Correct answer: 18.5% (19.5% per OSHA)
OSHA requires a minimum oxygen concentration of 19.5% for permit-required confined space entry to be considered safe.
Question 2: During a blowout, the first line of defense to control wellbore pressure is the:
- Diverter system
- Blowout preventer (BOP) stack
- Mud weight (drilling fluid density) (Correct answer)
- Choke manifold
Correct answer: Mud weight (drilling fluid density)
Primary well control relies on maintaining sufficient drilling fluid density to exert hydrostatic pressure that exceeds formation pressure.
Question 3: Which class of fire extinguisher is appropriate for electrical equipment fires?
- Class A
- Class B
- Class C (Correct answer)
- Class D
Correct answer: Class C
Class C extinguishers use non-conductive agents suitable for energized electrical equipment fires.
Question 4: An environmental impact assessment (EIA) for a new drilling project is primarily used to:
- Calculate project profitability
- Identify and mitigate potential environmental consequences before project approval (Correct answer)
- Determine royalty payment schedules
- Certify equipment pressure ratings
Correct answer: Identify and mitigate potential environmental consequences before project approval
An EIA evaluates potential environmental impacts and proposes mitigation measures before regulatory approval is granted.
Question 5: The Safety Case regime, widely adopted offshore, requires operators to demonstrate that:
- All risks have been reduced to zero
- Major accident hazard risks are reduced to ALARP and a safety management system is in place (Correct answer)
- Only financial losses from incidents are covered by insurance
- Equipment is replaced on a fixed 5-year schedule
Correct answer: Major accident hazard risks are reduced to ALARP and a safety management system is in place
A Safety Case requires demonstration that major hazard risks are ALARP and that an effective SMS governs ongoing operations.
Question 6: What type of gas monitoring alarm typically triggers evacuation at 10% of the Lower Explosive Limit (LEL)?
- Toxic gas alarm
- Fire alarm
- Combustible gas detector alarm (Correct answer)
- Oxygen depletion alarm
Correct answer: Combustible gas detector alarm
Combustible gas detectors are set to alarm at 10–20% LEL to warn personnel before a flammable atmosphere can form.
Question 7: Under the US Clean Water Act, what is the maximum oil sheen permissible from an offshore discharge?
- Any sheen is prohibited (Correct answer)
- A light iridescent sheen is permitted if no free oil is visible
- Up to 15 mg/L oil in produced water is allowed
- No federal standard applies offshore
Correct answer: Any sheen is prohibited
The Clean Water Act prohibits discharge of oil in quantities that cause a film, sheen, or discoloration on the water surface.
SPE Health, Safety, and Environment 3
What is the minimum required oxygen concentration for normal work in a confined space according to OSHA standards?