Weighting up is the critical operation while drilling so we need to know how much weighting agent such as barite, calcium carbonate, hematite, etc required in order to get proper weight to prevent a well control situation. This mud calculation is separated into several sub topics so you can follow each one easily. For this article, it 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
500 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 = 201 sacks (round up)
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 1,003 sacks (201×500/100).
Ref books: Lapeyrouse, N.J., 2002. Formulas and calculations for drilling, production and workover, Boston: Gulf Professional publishing.
Bourgoyne, A.J.T., Chenevert , M.E. & Millheim, K.K., 1986. SPE Textbook Series, Volume 2: Applied Drilling Engineering, Society of Petroleum Engineers.
Mitchell, R.F., Miska, S. & Aadny, B.S., 2011. Fundamentals of drilling engineering, Richardson, TX: Society of Petroleum Engineers.