Complex Evaluation Procedure of Gas Saturation Ratio and Lower Limit of Porosity, in the Reservoirs of the Orenburg Gas Condensate Field.

A method of interpretation of the results of core analysis for a pair of boreholes situated close to one another is presented. One of the boreholes was drilled with an anhydrous and another with a relay solution. This method permits a reliable evaluation of the value of the gas saturation coefficient of the reservoir rocks of the Orenburg gas-condensate deposit with respect to the balance of residual fluids, as well as to identify the permeable intervals (effective thicknesses) by the fact of penetration of the drilling fluid into the core. A complex interpretation of core and geophysical data has made it possible to select two types of reservoir and to evaluate the bottom limits of porosity of each of them.