Gas/mud ratio

Input(s)

$d_{b}$: Bit Diameter (in.)

R: Penetration Rate $(\mathrm{ft} / \mathrm{h})$

$S_{g}$: Gas Saturation (fraction)

Ø: Formation Porosity (per cent)

$p$: Pressure (psi)

z: Gas Compressibility Factor (dimensionless)

$t$: time (h)

$q_{m}$: Mud Circulation Rate (bbl/min)

Output(s)

$r_{m}$: Gas/Mud Ratio $(\mathrm{SCF} / \mathrm{bbl})$

Formula(s)

$$ r_{m}=\frac{d_{b}^{2} R Ø S_{g} p}{310 z T q_{m}} $$

Reference(s)

Watson, D., Brittenham, T., \& Moore, P. L. (2003). Advanced Well Control (Vol. 10). Society of Petroleum Engineers, Page: 19.