Question

The average bulk density of a fully saturated sandstone reservoir with a fractional porosity of 0.23 is ________ g/cc. \text{[round off to 2 decimal places]}

Hint:

For calculating bulk density, use the weighted average formula considering the porosity and densities of the fluid and matrix.

Answer 1

Correct Answer: 2.24

The average bulk density \( \rho_b \) of a fully saturated sandstone is given by the formula: \[ \rho_b = \phi \times \rho_f + (1 - \phi) \times \rho_m \] where: - \( \phi = 0.23 \) is the fractional porosity,
- \( \rho_f = 1.05 \, \text{g/cc} \) is the fluid density,
- \( \rho_m = 2.63 \, \text{g/cc} \) is the matrix density for sandstone.
Substituting the values into the equation: \[ \rho_b = 0.23 \times 1.05 + (1 - 0.23) \times 2.63 \] \[ \rho_b = 0.2415 + 2.0261 = 2.2676 \, \text{g/cc} \] Rounding off to two decimal places, the average bulk density is: \[ \boxed{2.27 \, \text{g/cc}}. \]