Investigation of Marcellus Shale Reservoir Variability within Different Deposition Systems
Bank, Gregory C.; Reed, Jason S.
Many factors can influence the productivity of shale resource plays, especially reservoir quality. Shale gas reservoir quality variability is examined here to quantify observed differences within a gross depositional system framework.
Pairs of closely spaced vertical wells have been drilled in each of three major gross depositional systems within the Marcellus shale. Shelf, slope and basin deposystems have been interpreted and mapped using well logs and core. These depositional systems serve as a priori groups to investigate the ranges of reservoir quality variability stratigraphically and spatially. Qualitative log observations indicate that the ranges of raw curve values and reservoir quality metrics vary depending on where data set is positioned within the basin. The purpose of this study is to better quantify these differences.
Since risk and uncertainty correlate to variability, the output of this exercise could be used to populate quantitative risk models and perhaps help operators deliver more consistent results. For example, if it can be demonstrated that certain stratigraphic intervals have less variance than others, then perhaps targeting those sections could yield more predictable well results.
AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013