Date(s) - 03/10/2020
11:30 am - 1:00 pm
Dilation and Slip Tendency Analysis:
Connections to Stress State, Failure Mode, and Fracture-Controlled Fluid Flow
Kevin J. Smart and David A. Ferrill
Southwest Research Institute, San Antonio, Texas
Mechanical stratigraphy and stress state are key controls on the development of geologic structures. For example, faults can have complicated shapes caused by variations in failure modes as well as by linkage of fault segments, and fractures will develop in some beds but not others. Early formed structures can also undergo later reactivation under widely varying stress conditions. Understanding the present-day conduit or barrier behavior of faults and fractures requires analysis in the in-situ stress state but is aided by analyzing the structural history under evolving tectonic regimes. In this presentation, we explore the related concepts of failure mode and resolved stress analysis. We provide examples of a range of geologic structures – normal faults, thrust faults, tectonic stylolites, and extension fractures – that formed and then evolved under changing stress conditions during the Laramide, and Basin and Range tectonism in west Texas. We discuss the utility of using relative dilation tendency versus slip tendency as a predictor of deformation behavior, and suggest this parameter space as a new tool for evaluating conduit versus seal behavior of geologic structures.
Kevin J. Smart
Southwest Research Institute
Kevin Smart received his B.S. degree in geology from Allegheny College in 1989, his M.S. degree in geology from the University of New Orleans in 1992, and his Ph.D. in geology from the University of Tennessee in 1996. Dr. Smart is a structural geologist with extensive expertise in computational solid mechanics. His experience spans structural geology and geomechanics, nonlinear finite element and discrete element analyses, field mapping, strain and microstructural analyses, and geologic fracture analysis.
Dr. Smart joined Southwest Research Institute in 2003 and is currently the manager of the Earth Science section in the Space Science & Engineering Division. In this capacity, he works with department staff to develop projects for a range of clients, with emphasis on oil and gas exploration and production, groundwater resource analysis, and natural hazard assessment. In addition, Dr. Smart is part of a team conducting an integrated program of structural geology and geomechanics research for the oil and gas industry, including site-specific studies in Texas, New Mexico, Colorado, California, and Canada. His work in this area includes using ABAQUS® geomechanical models to predict fracture distributions in hydrocarbon reservoirs, analyzing the effect of complex stress fields on borehole stability, and simulating hydraulic fracturing in mechanically stratified geologic systems with particular emphasis on unconventional resource plays (e.g., Permian Basin, Eagle Ford Shale, Monterey Formation). In addition, he has analyzed the effects of energy extraction on geological fault stability and supported design of large-scale laboratory experiments of rock mechanical processes. Together with other division staff, he has conducted NASA-sponsored field-analog and numerical modeling (PFC®) research to better understand the development of pit crater chains, landslides, and wrinkle ridges on Mars.