Permeability and porosity of alluvial fan deposits vary greatly as a function of depositional process and differential response to diagenesis. In general, streamflow deposits have greater permeability and porosity than debris and mudflow deposits. Finer grained but better sorted distal fan deposits are highly permeable and porous. Because of increased sorting, mid- and distal parts of the fan probably have better and more predictable reservoir quality than proximal parts. Little is known of directional permeability within alluvial fan reservoirs, but paleochannels can be expected to act as preferred pathways of flow. | Permeability and porosity of alluvial fan deposits vary greatly as a function of depositional process and differential response to diagenesis. In general, streamflow deposits have greater permeability and porosity than debris and mudflow deposits. Finer grained but better sorted distal fan deposits are highly permeable and porous. Because of increased sorting, mid- and distal parts of the fan probably have better and more predictable reservoir quality than proximal parts. Little is known of directional permeability within alluvial fan reservoirs, but paleochannels can be expected to act as preferred pathways of flow. |