GATE Petroleum Engineering Practice Quiz

Question 1

A dry core plug has a bulk volume of 30 cm^3 and a grain volume of 18 cm^3 measured by helium expansion. What is the porosity of the core plug?

Accepted Answer

40%

Question 2

Which porosity measurement method is most suitable for determining grain volume of a tight sandstone core because the gas penetrates very small connected pores effectively?

Accepted Answer

Helium porosimetry

Question 3

Two core plugs have identical porosity, mineralogy, and fluid saturation. Plug A has larger, better-connected pore throats than Plug B. Which statement is correct?

Accepted Answer

Plug A is likely to have higher permeability

Question 4

In an unsteady-state pressure-pulse decay permeability test on a very tight core, why is this method preferred over a conventional steady-state flow test?

Accepted Answer

Because measurable steady flow rates are too small in very tight rocks, while pressure transient response can still be analyzed

Question 5

Why is a Klinkenberg correction applied to gas permeability measurements on core samples?

Accepted Answer

To correct for gas slippage at low mean pressures and estimate liquid-equivalent permeability

GATE Petroleum Engineering

Quizzes

Porosity and Permeability Measurement Fundamentals | GATE Petroleum Engineering

Drilling Fluid Properties Fundamentals | GATE Petroleum Engineering