Fracture and Mechanical Stratigraphy of a Carbonate Sequence, Southern Ozark Dome, NW Arkansas
Earth and Atmospheric Sciences, University of Nebraska - Lincoln, Lincoln, NE, USA
Identifying natural fracture patterns and connectivity in an area gives key insights into potential migration pathways of subsurface fluids such as oil and natural gas as well as providing a detailed look into the local tectonic history.
The Ozark Dome is an ideal site due to its expected multiple fracturing events resulting from its multi-stage deformation history. Additionally, the stratigraphy of the area is similar to key onshore carbonate reservoirs currently being exploited, notably the Madison Formation, where fractures play a large role in reservoir permeability.
This study will develop a mechanical and fracture stratigraphy for a sequence of Pennsylvanian aged (320-298 Ma) carbonate rocks using field observations and digital mapping. Data to be collected includes fracture intensity, length, and abutting relationships; and rock hardness data collected from a Schmidt Hammer. Data analysis programs (such as stereonet programs and MOVE structural software) will aid in the interpretation of the mechanical and fracture stratigraphy data, elucidating the tectonic history of the field area during the Pennsylvanian. In addition, the completion of this study will contribute to developing a set of best practices for creating and interpreting mechanical and fracture stratigraphies that are applicable to other carbonate sequences worldwide.
Expected results include identifying evidence of several phases of deformation, creating detailed mechanical and fracture stratigraphies, and collecting detailed fracture observations from outcrop, allowing an understanding of the tectonic history of the area during the Pennsylvanian, and contributing to the growing understanding of the connectivity of natural fracture patterns in a carbonate sequence.
AAPG Search and Discovery Article #90199 © 2014 AAPG Foundation 2014 Grants-in-Aid Projects