Weight up is the critical operation while drilling so we need to know how to weight up with weighting agent such as barite, calcium carbonate, hematite, etc. I have separate about mud calculation into several sub topic so you can follow each topic easily. This time I will demonstrate how to calculate how many sacks of barite needed to increase mud weight in ppg with barite. (average specific gravity of barite – 4.2)
The formula for weight up with barite is listed below:
Sacks of Barite per 100 bbl of mud = 1470 x (W2 – W1) ÷ (35 – W2)
Where; W1 = current mud weight
W2 = new mud weight
Example: Determine the number of sacks of barite required to increase the density of
100 bbl of 10.0 ppg (W1) mud to 13.0 ppg (W2):
Sacks of Barite per 100 bbl of mud = 1470 x (13.0 – 10.0) ÷ (35 – 13.0)
Sacks of Barite per 100 bbl of mud = 200.5 sacks
If you have total volume of 500 bbl of mud, the barite required to increase mud weight from 10.0 ppg to 13.0 ppg is 1,002.5 sacks (200.5×500/100).
Please find the Excel sheet used for weighting up with Barite.
Ref: 
Formulas and Calculations for Drilling, Production and Workover, Second Edition
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July 23rd, 2009 at 9:08 am
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