Initial volume required to achieve a volume with calcium carbonate

Input(s)

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

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

$V_{f}$: Final Volume (ppg)

Output(s)

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

Formula(s)

$$ V_{i}=V_{f} * \frac{22.5-W_{2}}{22.5-W_{1}} $$

Reference(s)

Formulas and Calculations for Drilling, Production and Workover, Second Edition, Lapeyrouse, Page: 83.