The image above represents a gas recovery factor.

To compute for the gas recovery factor, three essential parameters are needed and these parameters are **initial pressure(P _{i}), initial compressibility factor (Z_{i}) **and

**P/Z Ratio (**

^{P}/_{Z}).The formula for calculating the gas recovery factor:

RF_{G} = 1 – ^{P}/_{Z}.^{Pi} / _{Zi}

Where;

RF_{G} = Gas Recovery Factor (P, Z)

P_{i} = Initial Pressure

Z_{i} = Initial Compressibility Factor

^{P}/_{Z} = P/Z Ratio

Let’s solve an example;

Find the gas recovery factor when the initial pressure is 12, the initial compressibility factor is 7 and the P/Z ratio is 36.

This implies that;

P_{i} = Initial Pressure = 12

Z_{i} = Initial Compressibility Factor = 7

^{P}/_{Z} = P/Z Ratio = 36

RF_{G} = 1 – ^{P} / _{Z}.^{Pi} / _{Zi}

RF_{G} = 1 – 36[^{12} / _{7}]

RF_{G} = 1 – 36[1.714]

RF_{G} = 1 – 61.714

RF_{G} = -60.714

Therefore, the **gas recovery factor **is **-60.714.**