CPG CPG Basin Analysis & Structural Geology 2

Question 1

Strike-slip (wrench) faults most commonly create hydrocarbon traps through which structural mechanism?

Accepted Answer

Flower structures and en-echelon folds

Answer

Strike-slip faults generate positive and negative flower structures and en-echelon folds along fault bends and stepovers that can form effective traps.

Question 2

Subsidence analysis (backstripping) in basin analysis is primarily used to:

Accepted Answer

Separate tectonic subsidence from sediment loading effects

Answer

Backstripping removes the effect of sediment loading to isolate tectonic subsidence, which reveals the basin's driving mechanism and thermal history.

Question 3

Which kerogen type is most prone to generating oil rather than gas?

Accepted Answer

Type II (algal/marine, liptinite-rich)

Answer

Type II kerogen, derived from marine algae and plankton, has a high hydrogen index and generates primarily oil at peak maturity.

Question 4

Structural closure in a four-way dip closure trap is defined as:

Accepted Answer

The area enclosed by the lowest closing contour around a structural high

Answer

Structural closure is the area enclosed by the lowest structural contour that completely surrounds the closure, limiting the trap's capacity to hold hydrocarbons.

Question 5

In the context of secondary migration, hydrocarbons move from source rock to trap primarily via:

Accepted Answer

Buoyancy-driven flow along carrier beds and faults

Answer

Secondary migration occurs as hydrocarbons, being less dense than water, rise buoyantly through permeable carrier beds and along faults until they are trapped.

(CPG) Certified Petroleum Geologist Practice Test

(CPG) Certified Petroleum Geologist Practice Test

CPG CPG Basin Analysis & Structural Geology 2