Injectivity Index

on . Posted in Drilling Engineering

Injectivity index, abbreviated as II, is used to evaluate the performance of a well when injecting fluids, such as drilling mud or other injection fluids, into the reservoir.  It quantifies the ease with which a well can accept injected fluid and is a critical measure for understanding the efficiency of fluid injection operations. 

Injectivity Index Formula

  • When referring to liquid volumes at stock tank conditions, use the units of Stock Tank Barrels (STB).

\( II \;=\; \dfrac{ q }{ p_{wf} - p  }\)     (Injectivity Index)

\( q \;=\;  II \cdot ( p_{wf} - p)  \)

\( p_{wf} \;=\; \dfrac{ q }{ II } + p \)

\( p \;=\;   p_{wf} - \dfrac{ q }{ II } \)

Symbol English Metric
\( II \) = Injectivity Index \(bbl \;/\; day \;/\; psi\) -
\( q \) = Injection Well Flow Rate \(bbl \;/\; day\) -
\( p_{wf} \) = Well Flow Pressure (psi) \(lbf \;/\; in^2\) -
\( p \) = Reservoir Pressure (psi) \(lbf \;/\; in^2\) -

 

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Tags: Drilling