Effect of clay mineralogy and pore fluid chemistry on fluid flow in fault zones

• Applicant: Dr. Julia Behnsen
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: from 2009 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 84562314

Understanding the role of faults in controlling subsurface fluid flow is of critical importance for a number of geological applications. Retardation of fluid flow can lead to the development of excess pore fluid pressures which will control fault mechanics and the nucleation of earthquakes. The secure positioning of deep waste repositories and the recovery of hydrocarbons from structurally complex reservoirs also depends on detailed understanding of subsurface fluid flow. Previous studies have suggested that fault rocks that contain clays have significant physicochemical interactions with pore fluids (in particular water) that can affect their permeability and strength at upper crustal levels. The aim of this project is to measure the potential effect of clay mineralogy and pore water chemistry at elevated pressures and temperatures on the permeability of fault rocks. This study will combine a systematic experimental investigation into the effect of mineralogy and pore fluid chemistry on the fluid flow properties of non-swelling clays under high pressure and elevated temperatures with microstructural observations and mineralogical characterization of naturally-occurring clay-bearing fault rocks. The results will be used to develop and enhance models of fluid flow through fault zones.

• DFG Programme: Research Fellowships
• International Connection: United Kingdom
• Host: Professor Dr. Daniel Faulkner