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.