# Productivity Index for a Gas Well

## Productivity Index for a Gas Well formula |
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\( J \;=\; \mu \; h \;/\; 1422 \; T \; [\; 0.5 \; ln \; ( 4 \; A \;/\; 1.781 \; k \; WB_r^2 ) + S \;] \) | ||

Symbol |
English |
Metric |

\( J \) = Productivity Index for a Gas Well | \(MSCF/day/psi^2/cP\) | - |

\( \mu \) (Greek symbol mu) = Permability | \(mD\) | - |

\( h \) = Thickness | \(ft\) | - |

\( T \) = Temperature | \(R\) | - |

\( ln \) = Natural Logarithm | \(dimensionless\) | - |

\( A \) = Drainage Area | \(ft^2\) | - |

\( k \) = Shape Factor | \(dimensionless\) | - |

\( WB_r \) = Wellbore Radius | \(ft\) | - |

\( S \) = Skin | \(dimensionless\) | - |