Not all formations in a reservoir are permeable and/or contain clean hydrocarbon resources. The net-to-gross ratio (NtG) of a reservoir is a measure of the quality and economic viability of a reservoir. In order to determine the NtG a series of cut-offs are applied to several calculated reservoir properties, such as the volume of shale present in the reservoir and the formation porosity, permeability and water saturation.
Download Chapter Three of our well log analysis eGuide to learn how to:
1. Calculate Vshale from Gamma Ray logs
2. Calculate Vshale from combined Density-Neutron logs
3. Determine formation Permeability from a Porosity log
Use this chapter as a stand-alone quick reference, or combine it with the other chapters in this eGuide for a comprehensive guide to well log analysis.