# Initial volume required to achieve a volume with hematite

## Input(s)

\(W_{1}\): Initial Mud wt. (ppg)

\(W_{2}\): Required mud wt. (ppg)

\(V_{f:} \quad\) Final Volume \((\mathrm{ppg})\)

## Output(s)

\(V_{i}\): Starting Volume (bbl)

## Formula(s)

\[
V_{i}=V_{f} * \frac{40-W_{2}}{40-W_{1}}
\]

## Reference(s)

Formulas and Calculations for Drilling, Production and Workover, Second Edition, Lapeyrouse, Page: 84.