Effective logging programs are available for wells drilled with non-conductive oil muds. The basic log in such a program is the simultaneously recorded Gamma Ray-Induction Survey. This log provides the primary means for correlation, depth control, and for determination of resistivity values for qualitative and quantitative interpretation.
The Sonic Log, used in conjunction with the resistivity values from the Induction Log, serves as an excellent detector of hydrocarbon-bearing zones.
Determination of porosity is best accomplished with the Formation Density Log. In addition to supplying reliable values of effective porosity, this is the most accurate logging means of determining the lithology of the sand-shale sequences, found in this area.
The use of Induction, Sonic, and Formation Density Logs provides data for complete interpretation of water saturation, effective porosity, and shale content.
Other wireline tools, such as Neutron, Dipmeter, Sidewall Coring, and Wireline Formation Testing, are effective in oil muds.
