Gas Flow Rate into the Wellbore formula |
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| \( Q \;=\; \dfrac{ 0.007 \cdot k \cdot \partial p \cdot L }{ \eta \cdot ln \left( \dfrac{ R_d }{ R_w } \right) \cdot 1440 }\) | ||
| Symbol | English | Metric |
| \( Ri \) = Flow Rate | \(bbl \;/\; min \) | - |
| \( k \) = Permeability | \(mD\) | - |
| \( \partial p \) = Pressure Differential (psi) | \(lbf \;/\; in^2\) | - |
| \( L \) = Length of Section Open to Wellbore | \(ft\) | - |
| \( \eta \) (Greek symbol eta) = Initial Gas Viscosity | \(cP\) | - |
| \( ln \) = Natural Logarithm | - | |
| \( R_d \) = Drainage Radius | \(ft\) | - |
| \( R_w \) = Wellbore Radius | \(in\) | - |
Gas flow rate into a wellbore during drilling depends on several factors, such as the reservoir pressure, permeability, porosity, gas composition, and the specific drilling conditions (underbalanced or overbalanced drilling). There’s no universal value for this, it’s highly situational and determined by the reservoir’s characteristics and the drilling operation itself.
