Question

The laboratory analysis data obtained from the core is as follows:
Weight of clean dry core in air = 30 g
Weight of core completely saturated with oil = 32 g
Weight of saturated core completely immersed in oil = 24 g
If the density of oil used for saturation of core during the experiment is 0.88 g/cc, then the effective porosity of the core is .......... % (rounded off to two decimal places).

Hint:

Effective porosity represents the void space in the core that is interconnected and able to carry fluids. Use weight differences to determine the effective porosity.

Answer 1

Correct Answer: 24

The effective porosity can be calculated using the following formula:
\[ \phi = \frac{W_s - W_0}{W_s - W_d} \] where:
- \( W_s \) is the weight of the core saturated with oil,
- \( W_0 \) is the weight of the saturated core completely immersed in oil,
- \( W_d \) is the weight of the clean dry core.
Substituting the given values:
\[ \phi = \frac{32 - 24}{32 - 30} = \frac{8}{2} = 4 \] To find the effective porosity in terms of percentage, multiply by 100:
\[ \phi = 4 \times 100 = 24.00 \, % \] Thus, the effective porosity of the core is approximately between 24.00 and 26.00 %.