Fracturing, sealing and fluid flow in reservoirs and fault zones (co-organized)
|Co-Convener: Francois Renard|
Fracturing and fluid-rock interaction occur by a variety of different processes, at different temporal and spatial scales. For example, flow of fluids, chemical and mechanical compaction, or mineral precipitation can lead to high stress gradients in rocks so that hydrofractures develop, which in turn may lead to enhancement of the flow and changes in stress. Stress drops due to hydrofracturing may lead to sudden precipitation events that then may seal hydrofractures (forming veins) and slow down fluid flow. Sealing can also occur in pores, for example in areas surrounding stylolites, where material is derived from dissolution on the stylolite. The actual sealing process depends on crystal growth processes in veins and in pores. In contrast to the relatively fast hydrofracturing the crystal growth processes may be slow, driven by diffusion of matter through a permeable host rock or along grain boundaries. Mixing of different fluids or spatial variations in the chemical potential may lead to local disequilibrium and precipitation of material in veins or in pores, which in turn changes the permeability and possibly the physical properties of the rock. This is of key interest to understand reservoirs in sedimentary basins. Quite similar processes involving the behavior of hydrothermal fluids in oceanic or continental crusts are of special interest to understand the way fluids could migrate within the crustal-scale reservoirs and even reach the mantle through fault systems. In this session we invite contributions that investigate the dynamics of fractures, fracture-sealing, pore-sealing, and fluid flow, focusing on the physical, chemical and mechanical coupling between the various processes. We invite field-, numerical- and experimental studies that aim to describe and quantify the fluid-flow mechanisms whatever the temporal and spatial scales.