Traditional methods of exploration have not always yielded acceptable results when prospecting for organic rich shales. Most of these methods utilize logs to determine petrophysical properties of these potential reservoirs. Unfortunately, most of these techniques fail to use all of the information possible from their expensive log data. Organic rich shales typically have complex lithologies and exotic minerals that make algorithm-based solutions virtually impossible. Standard porosity and water saturation equations do not work as intended. Furthermore, production controls on the reservoir are not limited to gas-in-place in the reservoirs.
Integration of all of the data in each log, along with all of the data from all wells in an area, is required to arrive at a complete solution. The use of neural networks and resistivity modeling to fill in the gaps in the logging suites used in different vintages of wells will be demonstrated. Unique methods of integrating core data to log data will also be shown. After analysis, many petrophysical properties of these unconventional reservoirs, such as porosity, TOC, lithology, water saturation and Young’s modulus, can be available.
A case study showing the use of these methods in the Barnett Shale of the Fort Worth Basin will be presented. A comparison of logs between the Barnett Shale in the Fort Worth and Permian Basins will also be shown.