To determine the total number of sacks of tail cement required, you generally need the following information:
Volume of the wellbore or casing annulus - You need to calculate the volume that needs to be filled with cement.
Yield of the cement - This is usually given in cubic feet per sack (or barrels per sack). It represents how much volume each sack of cement will cover.
Safety factor - Often a safety factor (commonly 1.1 to 1.3) is applied to account for potential losses or overage during the job.
Total Number of Sacks of Tail Cement Required Formula |
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| \( N \;=\; \dfrac{ V_c }{ Y_c } \cdot SF \) |
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| Symbol | English | Metric |
| \( N \) = Total Number of Sacks of Tail Cement Required | \(dimensionless\) | - |
| \( V_c \) = Total Volume to be Cemented | \(ft^3\) | - |
| \( Y_c \) = Cement Yield (Usually Given by the Cement Manufacturer) | \(ft^3\;/\;sack\) | - |
| \( SF \) = Safety Factor | \(dimensionless\) | |
Total Number of Sacks of Tail Cement Required Formula |
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\( N \;=\; N_a + N_c \) (Total Number of Sacks of Tail Cement Required) \( N_a \;=\; N - N_c \) \( N_c \;=\; N - N_a \) |
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| Symbol | English | Metric |
| \( N \) = Total Number of Sacks of Tail Cement Required | \(dimensionless\) | - |
| \( N_a \) = Sacks Required by Annulus | \(dimensionless\) | - |
| \( N_c \) = Sacks Required by Casing | \(dimensionless\) | - |
