Types of Lateral Variability in a Marcellus Shale Prospect

Gregory C. Bank
Seneca Resources Corp., Pittsburgh, PA, [email protected]

Lateral continuity of reservoir properties by zone is often assumed when designing multi-stage completions in horizontal gas shale wells. Such reservoir properties include porosity, saturations, in situ stresses, mineralogy and produced gas composition. Extensive geophysical log data from two closely-spaced vertical wells are binned into vertical flow units. Resulting data are compared in order to understand the degree of lateral variability an adjacent horizontal wellbore will sample.

Results from the vertical wells are compared to cased-hole logs run in an offset horizontal well. While several reservoir properties appear to be statistically similar within flow units along a horizontal wellbore, others vary abruptly on opposing sides of a structure or change gradually over the course of a wellbore.

The importance of understanding lateral variability is highlighted via comparison of geologic data to stage-level completion data in two additional horizontal wells.

AAPG Search and Discovery Article #90154©2012 AAPG Eastern Section Meeting, Cleveland, Ohio, 22-26 September 2012