Current Research on the Mt. Simon Geology; Refining the Lower Mt. Simon Depositional Interpretation By: Jared T. Freiburg Illinois State Geological Survey freiburg@illinois.edu 5/17/2016 2.5 cm
Collaborators Nathan Webb (ISGS) Hannes Leetaru (ISGS) Arjan Reesink (U of I) Chris Patterson (ISGS) Markus Peltz (Greifswald, Germany) Georg Grathoff (Greifswald, Germany) Jim Best (U of I) Charles Monson (ISGS) Robert Ritzi (Wright State) Nils Clausen (U of I) Matt Krueger (U of I)
Outline Brief overview of the Mt. Simon geology with the assumption everyone knows some basics What we know, stratigraphic separation Diagenetic controls on reservoir properties compaction and cementation Refined Lower Mt. Simon depositional interpretation depositional environments controls and reservoir compartmentalization internal baffles, pore network modeling, and relative permeability
Mt. Simon Thickness In Illinois Depocenter of the Mt. Simon is in Northern and East-central Illinois Does not correlate with the depocenter of the Illinois Basin (visible with Precambrian topography) Illinois Basin Decatur Project Modified from Freiburg et al., 2014
Introduction At the Illinois Basin Decatur Project (IBDP) site the Mt. Simon Sandstone is divided into three sections (Upper, Middle, and Lower) based on unconformities and major depositional changes Five corresponding units (A through E) within sections are based on lithologic changes and reservoir properties A unit referred to as the Argenta underlies the M.t Simon and overlies the basement 1500 ft E D C B A Upper Middle Lower Argenta PC
Basic Stratigraphy and Structure The Argenta has variable thickness in wells and is unconformably separated from the overlying Mt. Simon Mt. Simon Units maintain similar thickess across wells. However, Unit surface topography follows Precambrian basement topography Suggests variable Precambrian topography during Argenta deposition and structural activity post Mt. Simon deposition Haven t been able to determine depth of Precambrian hill crest from seismic Eau Claire Formation MtS Unit E MtS Unit D MtS Unit C MtS Unit B MtS Unit A Argenta Precambrian Basement CCS1 VW1 CCS2 VW2
Unit Reservoir Property Heterogeneity Red indicates greater than 10% porosity
Anomalous porosity in the Lower Mt. Simon is controlled by the overall lack of cementation Why the diagenetic segregation?
Geochemical Separation! Genetically different fluids? Labotka et al., 2015
Future Work Clay minerals appear to be the single most important control on porosity preservation in the Lower Mt. Simon Diagenetic clays will be separated from Mt. Simon units and age dated (K-Ar) Why is this important?
Refined Interpretation of the Lower Mt. Simon Depositional Environment
Coastal Deposits
Lagoonal Deposits
Fluvial Deposits
Plains Deposits
Desert (Dune) Deposits
Lower Mt. Simon Depositional Heterogeneity
Precambrian topographic control on facies in the Lower Mt. Simon is likely until burial of crest. Testing this hypothesis with FMI directional data Why is this important?
Time Lapse Reservoir Saturation Logs
Baffles and Seals Mt. Simon Mudstone FIB-SEM-BSE Porosity = 0.02%
Relative Permeability 100000.0 10000.0 CO2/Brine Capillary Pressure (psi) 1000.0 100.0 10.0 1.0 0.1 0 0.2 0.4 0.6 0.8 1 Wetting Phase Saturation(-)
Conclusions Precambrian structure is visible through the Mt. Simon (more to follow) Compaction is normal throughout the Mt. Simon with anomalous porosity controlled by the overall lack of cements. Diagenetic history is diverse and compartmentalized as suggested from fluid geochemistry. Lower Mt. Simon is highly heterogeneous with base-level, climatic, basement topographic controls Pore network models of internal baffles suggest no long-term CO2 breakthrough
Acknowledgements The Midwest Geological Sequestration Consortium is funded by the U.S. Department of Energy through the National Energy Technology Laboratory (NETL) via the Regional Carbon Sequestration Partnership Program (contract number DE-FC26-05NT42588) and by a cost share agreement with the Illinois Department of Commerce and Economic Opportunity, Office of Coal Development through the Illinois Clean Coal Institute. The Midwest Geological Sequestration Consortium (MGSC) is a collaboration led by the geological surveys of Illinois, Indiana, and Kentucky. Landmark Graphics software via their University Donation Program and cost share plus Petrel software via Schlumberger Carbon Services.
Acknowledgements Some of this work is supported as part of the Center of Geological Storage of CO 2,an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science.