M3Engi, by oil level do you mean fluid level over pump?
If so, you can roughly calculate the fluid level over pump by doubling the pump intake pressure.
Though, if you wanted to get to a more accurate value, you can take the pump intake pressure value and subtract the casing pressure. Then plug that value into the following equation:
Head (Feet) = (2.309xPSI)/Specific Gravity of the Fluid
This method ignores the weight of the column of gas.