Calculate Water Requirement and Cement Yield as per Cement Slurry

This topic will teach you how to determine water requirement (gal/sack) and yield of cement (gallon/sack) as per cement slurry program.


The cement formula given from town is listed below:


Cement formula:

Class G cement

35% Silica sand (35% by weight of cement)

0.2 gps of chemical A

0.6 gps of chemical B

Required cement density = 15.5 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


Determine requirement (gal/sack), yield of cement


We still use the same concept as previous calculation:


Volume = Weight x Absolute Volume



Volume in gal/sack

Weight in lb/sack

Absolute volume in gal/lb


We can create table showing 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 0.2 ÷ 0.0974 = 2.053 0.0974 2.053 x 0.0974 = 0.2
Chemical B 0.6 ÷ 0.103 = 5.825 0.103 5.825 x 0.103 = 0.6
Water 8.33 x k 1/8.33 k
Total 94+32.9+1.0267+5.825+(8.33k) 3.591+1.5+0.2+0.6+k

where; k is the variable that must be solved.

Total weight per sack of cement =94+32.9+1.0267+5.825+8.33k = 133.7517 + 8.33k

Total volume of cement slurry per sack of cement = 3.591+1.5+0.2+0.6+k = 5.891 + k

Cement Density = Total weight per sack of cement ÷ Total volume of cement slurry

15.5 = (133.7517 + 8.33k) ÷ (5.891 + k)

Solve for k: k = 5.92

After k is solved, you will get water requirement and cement yield.

The water requirement is 5.92 gal/sack.

Yield of cement = 5.891 + 5.92 = 11.811 gal/sack

Ps: I did not give you the product name in this topic or anything related to any cementing companies because I want you to understand the calculation concept. If you understand the concept, everything will be good.

Ref books: Cementing Technology Books

Drilling Formula BookFormulas and Calculations for Drilling, Production and Workover, Second Edition

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6 Responses to Calculate Water Requirement and Cement Yield as per Cement Slurry

  1. Himesh says:

    how to calculated absolute volume?

  2. mohammadreza says:

    You have a mistake.Absolute volume is in gal/lb, but in top of the table it is in gal/sack

  3. shubham says:

    You have written Absolute Volume (.0103) of chemical B in table, which is not so what you have listed above (.103). Why?

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