Advanced petrophysical characterization of the Marcellus Shale

Abstract

To better understand the petrophysical characters of the Marcellus Shale and to identify pore system that contributes to the gas production, we conducted a series of petrophysical measurements. A positive correlation between porosity and total organic carbon (TOC) was observed in samples from the lowermost Marcellus Shale, whereas a different relationship was observed in samples from the lower parts of Marcellus Shale. These two geological units showed a difference in pore size distribution, which was obtained from mercury intrusion capillary pressure (MICP) test. In addition to this, detailed scanning electron microscope (SEM) observations of samples from the lower and lowermost parts of the Marcellus Shale reveal that the petrophysical properties and pore systems in these parts differ. In both parts, an abundant existence of nano pores is supported from N₂ adsorption test and these pores would play an important role in the gas production.