Preliminary analyses of core from the Marcellus Shale Energy and Environment Laboratory

Abstract

Natural gas production from the Marcellus shale is influenced by factors at many scales. At each scale, detailed characterization can provide insights that improve our understanding of how to best utilize these resources. Here we present a preliminary multiscale examination of core obtained from the Marcellus Shale Energy and Environment Laboratory (MSEEL) in Morgantown West Virginia, coupling well-log interpretations, millimeter to micron scale computed tomography (CT) scanning and physical laboratory measurements, geochemical sampling, and high-resolution isotope analysis.

Within 24 hours of extraction from the MSEEL 3H well, 112 feet of vertical core was CT scanned at the National Energy Technology Laboratory to examine the millimeter scale variations in structure. This data was coupled with P-wave velocity, X-ray fluorescence, magnetic susceptibility, and gamma density data obtained at 2 centimeter resolution along the length of the core using a Geotek Multi-Sensor core logger. Variation in natural constituents and locations of natural vertical fractures were examined to correlate with the field deployed well-logs.

These high resolution measurements were used to organize sampling protocols of preserved side-walls for in-situ isotope analysis and geochemical sampling. Measurement of metal isotope variability within the core will allow for improved understanding of the shale depositional environment and the range in variability expected for naturally-occurring geochemical tracers. Metal isotope signatures for Sr, Li, B and U are being evaluated in the homogenized samples through chemical extraction and analysis using multicollector ICP-MS techniques. Chemical variations in the shale due to variations in depositional environments may impact the pore scale reactions in the matrix. Geochemical analysis of the homogenized core samples, compared with results from analysis of drill cuttings, will provide additional insight into how drill cuttings may impact the environment. Preliminary results illustrate the heterogeneity of this formation, where small scale features influence the production processes and interactions during production. Work continues to link these laboratory observable properties to well-scale descriptions of the subsurface for upscaling and model development.

AAPG Datapages/Search and Discovery Article #90258 © 2016 AAPG Eastern Section Meeting, Lexington, Kentucky, September 25-27, 2016