CPA Petroleum Industry Fundamentals 3 — Questions and Answers
Question 1: What does API gravity measure in crude oil?
- The amount of natural gas dissolved in the oil
- The viscosity of the oil at standard temperature
- The density of oil relative to water (Correct answer)
- The sulfur content of the crude
Correct answer: The density of oil relative to water
API gravity is an inverse measure of crude oil density relative to water; higher API gravity indicates lighter (less dense) crude, which generally commands a higher price.
Question 2: In offshore drilling, what is the purpose of a 'blowout preventer' (BOP)?
- To prevent the drill bit from overheating
- To control unexpected pressure surges and prevent well blowouts (Correct answer)
- To stop wind from affecting the drilling platform
- To regulate mud flow into the formation
Correct answer: To control unexpected pressure surges and prevent well blowouts
A BOP is a large valve assembly installed at the wellhead to seal the wellbore and prevent uncontrolled release of oil, gas, or drilling fluids during a kick or blowout.
Question 3: What is 'natural gas liquids' (NGL)?
- Liquefied natural gas stored at cryogenic temperatures
- Hydrocarbon components heavier than methane extracted from natural gas (Correct answer)
- Condensate water produced with natural gas
- A byproduct of crude oil refining
Correct answer: Hydrocarbon components heavier than methane extracted from natural gas
NGLs are hydrocarbon components such as ethane, propane, butane, and natural gasoline that are heavier than methane and can be separated from the natural gas stream.
Question 4: Which drilling fluid property describes its resistance to flow?
- Density
- Viscosity (Correct answer)
- pH
- Filtration rate
Correct answer: Viscosity
Viscosity measures the resistance of drilling fluid to flow; it must be properly controlled to carry cuttings to the surface while allowing separation at the surface.
Question 5: What is the main purpose of casing in a wellbore?
- To reduce drilling costs
- To stabilize the wellbore and isolate geological formations (Correct answer)
- To increase the rate of penetration
- To guide the drill string direction
Correct answer: To stabilize the wellbore and isolate geological formations
Casing is steel pipe cemented into the wellbore to prevent the hole from collapsing, isolate different pressure zones, and protect groundwater from contamination.
Question 6: What does the term 'upstream' refer to in the petroleum industry?
- Pipeline transport from refineries to consumers
- Refining and processing of crude oil
- Exploration and production of oil and gas (Correct answer)
- Marketing and retail distribution
Correct answer: Exploration and production of oil and gas
Upstream refers to the exploration and production (E&P) segment, which includes finding oil and gas reserves and extracting them from the ground.
Question 7: What is 'reservoir pressure' in the context of oil production?
- The weight of the drilling mud column
- The natural pressure within a hydrocarbon-bearing formation (Correct answer)
- The pressure applied by surface pumps
- The pressure in the pipeline network
Correct answer: The natural pressure within a hydrocarbon-bearing formation
Reservoir pressure is the natural pressure existing within a petroleum-bearing formation that drives hydrocarbons toward the wellbore during production.
CPA Petroleum Industry Fundamentals 3
What does API gravity measure in crude oil?