Deformation and Alteration of Shale Smear, Black Diamond Mine, California
- Type of resource
- Date created
- August 01, 2001
The Stanford Shale Smear Project was an industrial affiliates project within the Stanford Structural Geology and Geomechanics Program in the Geological and Environmental Sciences Department in the School of Earth Sciences at Stanford University. The project was directed by Professor Atilla Aydin.
- Eichhubl, Peter (Author)
Entrainment of shale along faults or shale smear represents a significant mechanism providing fault seal in hydrocarbon reservoirs. This ongoing project is designed to asses the combined structural and diagenetic effects on permeability reduction of shale smear with the objective of establishing predictive tools for fault seal behavior as a function of the depositional, structural, and diagenetic evolution of petroliferous basins. For a shale smear exposed in an underground mine, preliminary mercury injection analyses indicate a reduction in shale smear permeability by 1-2 orders of magnitude compared to reference samples of undeformed shale taken 2 m away from the fault. Permeability reduction in shale smear correlates with a distinct fabric reorganization which is attributed to the combination of mechanical clay-particle reorientation and possible diagenetic clay neoformation. An observed reduction in smectite content and a corresponding increase in kaolinite component of shale smear is indicative of interaction of organic-rich shale with infiltrated meteoric fluids and suggests that water-mineral reactions are an integral component of shale smear formation. Continued investigations are proposed to refine sampling at this underground site for a quantitative assessment of compositional and rock physical heterogeneity and to extend sampling to faults in different depositional and burial diagenetic environments.
- Preferred Citation
- Eichhubl, Peter. (2001). Deformation and alteration of shale smear, Black Diamond Mine, California. Stanford Digital Repository. Available at: http://purl.stanford.edu/zt308ph9642
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