Correctness of the Comprehensive Interpretation of Well Logs Regarding to Geological Conditions and Calculation Methods

A great amount of unknowns resulting from a complicated lithology and from many logs run in a borehole causes that a set of equations in the comprehensive interpretation is great and sometimes indeterminate. In real geological conditions we sometimes get solutions that are different from laboratory estimates of porosity or other parameters. Discrepancies between lab measurements and geological data on one side and results of the comprehensive interpretation of well logs on the other side were the direct reason to examine the method of optimization adopted for solution. The proposed mathematical solution in the form of combined Monte Carlo and Gradient methods works as a tool assuring interpreter that the solution is correct. The general results obtained from Interlog-GeoWin were compared to ULTRA and Petrolog systems and the agreement was satisfied.