This topic will teach you how to determine total bulk cement and water for required cement volume.
Let’s learn from the example.
The calculated cement volume is 150 bbl. (Learn about cement volume calculation -> Calculate Cement (Oil Well Cement) Volume Required
The cement formula given from town is listed below:
Cement formula:
Class G cement
35% Silica sand
0.2 gps of chemical A
0.6 gps of chemical B
0.9 gps of chemical C
Required cement density = 15.9 ppg
The absolute volume of each material is listed below:
Class G cement = 0.0382 gal/lb
Silica sand = 0.0456 gal/lb
Chemical A = 0.0974 gal/lb
Chemical B = 0.103 gal/lb
Chemical C = 0.112 gal/lb
Determine total bulk cement and water requirement for 150 bbl of cement.
We still use the same concept as previous calculation:
Volume = Weight x Absolute Volume
Where:
Volume in gal/sack
Weight in lb/sack
Absolute volume in gal/sack
Firstly, we need to know how much volume of water per sack of cement.
The table below shows each component of cement slurry as shown below:
Weight (lb/sack) | Absolute volume(gal/lb) | Volume (Gal/sack) | |
1 sack of class G cement | 94 | 0.0382 | 94 x 0.0382 = 3.591 |
35% Silica sand | 0.35 x 94 = 32.9 | 0.0456 | 32.9 x 0.0456 = 1.5 |
Chemical A | 0.1 ÷ 0.0974 = 1.0267 | 0.0974 | 0.2 |
Chemical B | 0.6 ÷ 0.103 = 5.825 | 0.0103 | 0.6 |
Chemical C | 0.9 ÷ 0.112 = 8.036 | 0.112 | 0.9 |
Water | 8.33 x k | 1/8.33 | k |
Total | 94+32.9+1.0267+5.825 +8.036 + (8.33k) | 3.591+1.5+0.2 +0.6+ 0.9 + k |
k is a variable for water requirement.
Total weight per sack of cement =94+32.9+1.0267+5.825+8.036+8.33k = 141.7877 + 8.33k
Total volume of cement slurry per sack of cement= 3.591+1.5+0.2+0.6+ 0.9 + k = 6.791 + k
Cement Density = Total weight per sack of cement ÷ Total volume of cement slurry
15.9 = (141.7877 + 8.33k) ÷ (6.791 + k)
Solve for k: k = 4.466
The water requirement is 4.466 gal/sack.
Yield of cement = 6.791+4.466 = 11.257 gal/sack
Total cement volume is 150 bbl.
Convert bbl into gal by multiplied by 42 (1 bbl = 42 gallon)
150 bbl = 150 x 42 = 6,300 gallon
Determine total sacks of cement requires with this following equation.
Total sack of cement = Total Volume of Cement ÷ Yield of Cement
Where;
Total sack of cement is in sack.
Total volume of cement is gallon.
Yield of cement is gal/sack.
Total sack of cement = 6300 ÷ 11.257 = 560 sacks.
Determine total of water by this relationship.
Total water = water requirement x Total sack of cement
Where;
Total water in gallon
Water requirement in gps (gallon per sack)
Total of cement is sack
Total water = 4.466 x 560 = 2501 gal.
You can convert to bbl by divided by 42.
Total water = 2501 ÷ 42 = 59.5 bbl.
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.