Diagenetic analysis of the Nonesuch Shale for unconventional reservoir potential, Upper Peninsula, Michigan and Wisconsin, USA

Abstract

This study will examine the Nonesuch Shale in outcrop and core from Michigan and Wisconsin in order to place the unit within a petroleum system and determine its potential as an unconventional reservoir. We intend to investigate factors that control reservoir quality and its mechanical behavior. Biology is one variable involved in mudstone diagenesis and because the Nonesuch is of Precambrian age, this study will offer unique insight is to diagenesis in the presence of limited organic diversity. Facies, outcrop and core descriptions (Elmore et al. 1989; Stewart & Mauk 2017) will be updated from to better include aspects of the petroleum system such as storage potential and matrix flow capacity. Analysis will be conducted using XRD, thin sections, and SEM analysis. This work will allow comparisons to other siliceous, petroleum bearing shales in the USA. Thin section analysis will provide insight into grain associations, mineralogy and macro-diagenesis. We will also check for micro-porosity development in the thin sections using UV light techniques. Broken chip and Ar-milled samples will be examined in the SEM. This will tell us about the presence or absence of porosity, the associated cementation, pore geometry and morphology, and compaction history. Research on the organic matter will be incorporated from Imbus (1988; 1990), Colbert (2011), and Fourgani (2012). A paragenetic history will be constructed to allow some basic predictions regarding the timing oil and gas development compared to timing of diagenetic events in the Nonesuch Shale. Following analysis of the XRD, thin sections, SEM, and previously collected geochemical data (Imbus, 1990) findings will be compared to more organically diverse and siliceous shale formations such as the Woodford, Barnett, and Mowry.

AAPG Datapages/Search and Discovery Article #90351 © 2019 AAPG Foundation 2019 Grants-in-Aid Projects