CPA Petroleum Industry Fundamentals 2 — Questions and Answers
Question 1: Which type of hydrocarbon trap is formed when impermeable rock layers bend upward to create a dome-shaped structure?
- Fault trap
- Stratigraphic trap
- Anticline trap (Correct answer)
- Salt dome trap
Correct answer: Anticline trap
An anticline trap forms when rock layers fold upward into a dome, with the impermeable cap rock preventing hydrocarbons from escaping upward.
Question 2: What is the primary purpose of a Christmas tree on an oil well?
- To decorate the wellsite during holidays
- To control and regulate flow from the well (Correct answer)
- To support the drilling derrick
- To separate oil from water
Correct answer: To control and regulate flow from the well
A Christmas tree is an assembly of valves, gauges, and fittings installed at the wellhead to control and regulate the flow of oil and gas from the well.
Question 3: In petroleum geology, what does the term 'source rock' refer to?
- Hard rock used to anchor drilling equipment
- Rock from which drilling cuttings originate
- Organic-rich rock where hydrocarbons are generated (Correct answer)
- The bedrock beneath a reservoir
Correct answer: Organic-rich rock where hydrocarbons are generated
Source rock is organic-rich sedimentary rock where heat and pressure convert organic material (kerogen) into oil and gas over millions of years.
Question 4: What is 'secondary recovery' in oil production?
- Drilling a second well on the same lease
- Recovering oil from a second reservoir
- Injecting water or gas to maintain reservoir pressure (Correct answer)
- Processing crude oil a second time at the refinery
Correct answer: Injecting water or gas to maintain reservoir pressure
Secondary recovery involves injecting water or gas into a reservoir to maintain pressure and displace additional oil toward production wells after primary recovery declines.
Question 5: Which unit is most commonly used to measure crude oil volume in international trade?
- Cubic meter
- Barrel (Correct answer)
- Gallon
- Metric ton
Correct answer: Barrel
The barrel (bbl), equal to 42 US gallons or approximately 159 liters, is the standard unit for measuring crude oil volume in international trade.
Question 6: What is the function of a 'packer' in a wellbore?
- To pack drilling mud into the formation
- To seal the annular space between tubing and casing (Correct answer)
- To compress gas for pipeline transport
- To pack cuttings out of the well
Correct answer: To seal the annular space between tubing and casing
A packer is a downhole device that seals the annular space between the production tubing and the casing to isolate different zones and direct fluids into the tubing.
Question 7: What distinguishes 'tight oil' from conventional crude oil?
- Tight oil has a higher API gravity
- Tight oil is trapped in low-permeability formations requiring hydraulic fracturing (Correct answer)
- Tight oil is found at shallower depths
- Tight oil contains more sulfur compounds
Correct answer: Tight oil is trapped in low-permeability formations requiring hydraulic fracturing
Tight oil is trapped in low-permeability rock such as shale or tight sandstone and requires hydraulic fracturing and/or horizontal drilling to produce economically.
CPA Petroleum Industry Fundamentals 2
Which type of hydrocarbon trap is formed when impermeable rock layers bend upward to create a dome-shaped structure?