The presentation moves on to discuss basic log interpretation procedures. A background is given for the three basic logs that are required for interpretation. The first log indicates permeable zones and includes data for SP and GR, the second is the resistivity log that includes data for induction and laterolog, and the third is the porosity log that includes data for density, neutron, acoustic and other elements. The purpose of analyzing these logs is to determine the location of potential hydrocarbon producing zones and how much hydrocarbon, as either oil or natural gas, they contain. This section of the presentation also discusses the methods that can be used to locate these potential hydrocarbon producing zones, the methods used to obtain saturations and the methods used to obtain porosities. An idealized log set and instructions are provided to show how to read the three logs for permeability, resistivity and porosity.

This presentation transitions into a more detailed explanation of how to select productive zones. Using the idealized log set containing information on permeable zones, resistivity and porosity, the presentation describes how to identify the shale base line and then look at deviations from it on the spontaneous potential curve to locate permeable zones. It also describes how to search the resistivity curve for high resistivities which can indicate either hydrocarbons or low porosity. The presentation further...

Based on the idealized log set that was used throughout the later portion of the presentation, the rock resistivity (R0) is provided. Other constants are substituted into the equation including the porosity, cementation exponent, saturation exponent and water resistivity to solve for the water saturation. Finally, it discusses the different approaches needed to find the water saturation, and the equations used to do this, based on the information provided in the idealized log set. Two sample problems are provided for practice to determine if, based on conducting a resistivity analysis, it would be profitable to complete wells.
The overall purpose of this presentation is to walk through the process of resistivity analysis, log interpretation, productive zone selection and real world application of these techniques to determine the economics of completing wells. The initial equation and the math associated with it are detailed to define the resistivities through Archie's law. An idealized log set is provided to explain how to read the three basic logs in order to find productive zones. Finally, the steps provided through the presentation are used in a real world scenario that reflects the actual application of this process.