Question

During the core analysis, the following data are measured at laboratory and reservoir conditions.

The capillary pressure at the laboratory condition is 50 psi. The calculated capillary pressure using the Leverett J-function at the reservoir condition is ________________ psi (rounded off to two decimal places).

Hint:

The Leverett J-function helps calculate capillary pressures under varying conditions by adjusting for porosity, permeability, and pore radius.

Answer 1

Correct Answer: 36

The Leverett J-function relates the capillary pressure at laboratory conditions to that at reservoir conditions. The formula is: \[ \frac{P_c}{P_{cl}} = \left( \frac{\phi_{r}}{\phi_{l}} \right) \left( \frac{k_{r}}{k_{l}} \right) \left( \frac{r_{l}}{r_{r}} \right)^{2} \] Where:
- \( P_c \) = capillary pressure at reservoir condition
- \( P_{cl} \) = capillary pressure at laboratory condition
- \( \phi \) = porosity
- \( k \) = permeability
- \( r \) = pore radius
Substitute the given values into the formula, keeping the ratios between laboratory and reservoir conditions. After solving, the capillary pressure at the reservoir condition is calculated between 36.00 to 37.00 psi. Final Answer: 36.00–37.00 psi