Question

q1

a) True or False with decreasing reservoir pressure:

- oil viscosity decreases

- oil formation volume factor increases

- solution gas increases

b) why do we need to correct the gas permeability for Klinkenberg gas slippage?

Answer 1

Answer - 1

(a)

part-1

True

If a crude oil is undersaturated at the original reservoir pressure, viscosity will decrease slightly as the reservoir pressure decreases

part -2

True

As the pressure is reduced below the initial reservoir pressure, the oil volume increases due to the oil expansion.This behavior results in an increase in the oil formation volume factor.

Part-3
True

with decreasing reservoir pressure solution gas increases

ANSWER -(b)

This is because gas does not adhere to the pore walls as liquid does, and the slippage of gases along the pore walls gives rise to an apparent dependence of permeability on pressure.Therefore, to get the permeability equivalent to the brine permeability at formation condition Klinkenberg calibration is necessary.