To form an oil reservoir, cap rocks must be _______________.
A) porous
B) permeable
C) impermeable
D) thin

Question

Quizplus · Accepted Answer

Cap rocks must be impermeable, meaning they do not allow fluid to flow through them. This prevents the oil and gas from escaping the reservoir and being lost. Porous and permeable rocks are important for the formation of the reservoir itself, but not for the cap rock. Thin cap rocks may be effective in some cases, but impermeability is the most important characteristic.

To Form an Oil Reservoir, Cap Rocks Must Be _______________