Abstract: Utilizing Magnetic Resonance Imaging Logs, Open Hole Logs and Sidewall Core Analyses to Evaluate Shaly Sands for Water-Free Production

Dennis Taylor, John Morganti, Howard White, Bruce Noblett, Craig Phillips

NMR logging using the new "C" series Magnetic Resonance Imaging Logging (MRIL)^TM is rapidly enhancing formation evaluation throughout the industry. By measuring irreducible water saturations, permeability, and effective porosities, MRIL data can help petrophysicists evaluate low resistivity pays. In these instances, conventional open hole logs may not define all of the pay intervals. MRIL can also minimize unnecessary completions in zones of potentially high water-cut. This case study will briefly discuss MRIL tool theory and log presentation used with the conventional logs and sidewall cores. SEM analysis will show a good correlation of varying grain size sands with the T₂ distribution with the bulk volume irreducible from MRIL. Discussions of each well in the study area will show how water-free production zones were defined. Because the MRIL data was not recorded on one of the wells, the advanced petrophysical program HORIZON as used to predict the MRIL bulk volume irreducible and effective porosity to estimate productive zones. Discussion of additional formation characteristics, completion procedures, actual production and predicted producibility of the shaly sands will be presented.

- (MRIL)^TM is a trademark of NUMAR Corporation.

AAPG Search and Discovery Article #90960©1995 AAPG Southwest Section Meeting, Dallas, Texas