Petrophysics

Gas in place analysis

A detailed field, lab, and model based approach to improving understanding of gas in place calculations and how gas is stored in nano-sized pore space. This work supported a correction to the free gas component of the GIP calculation, specifically accounting for the volume of gas occupied by the adsorbed gas phase (detailed by Ambrose et al., 2012; SPE 131772). Additional work in collaboration with Randy Blood, Ashley Douds, and Merril Stypula is being compiled and prepared for AAPG 2020 and URTeC 2020.

Automated target selection

An automated approach for selecting the optimum target within the Marcellus interval was developed. This process was evaluated for accuracy relative to manual target selections. The automated target was the mathematically optimum target within the interval based on select petrophysical curves in combination with pre-analysis filtering. In some cases it was found that the mathematically optimum target was not coincident with the operationally preferred target. The method was also useful for understanding how the optimum target changed both stratigraphically and geographically.

Cross-correlation for automated top selection

Automated top selection was initially built in support of a larger project. The initial workflow utilized cross-correlation to identify the most similar gamma ray signature in a nearby offset log. Log stretch and compaction allowed for accounting of thickness changes of the strata from one log to the next. This process proved successful for its required purpose, but ultimately was not fully needed. Future plans included the inclusion of additional log curves, and K-nearest-neighbor for automatic identification of the nearest offset logs.