The concept of mud volume increase due to adding calcium carbonate is as same as the mud volume increase by adding barite. The formula for calculating volume increment is just different only one factor which is 22.5 for calcium carbonate but 35 is used for barite case. Please follow the formula below for determining volume increase because of adding calcium carbonate.
Volume increase per 100 bbl of mud due to adding Calcium Carbonate = 100 x (W2 – W1) ÷ (22.5 – W2)
Where; W1 = current mud weight in ppg
W2 = new mud weight in ppg
Example: Determine the volume increase when increasing the density with calcium carbonate from 10.0 ppg (W1) to 13.0 ppg (W2):
Volume increase per 100 bbl of mud =100 x (13.0 – 10.0) ÷ (22.5 – 13.0)
Volume increase per 100 bbl of mud = 31.58 bbl
If you have total volume of 500 bbl of mud, the volume increase due to adding calcium carbonate will be equal to 157.9 bbl (31.58 x 500 ÷ 100).