DIAGENETIC CLAY PRECIPITATION IN SHALES: A PROPOSED MODEL FOR SEAL PERMEABILITY AND BIODEGRADATION OF RESERVOIRED HYDROCARBONS

摘要

A thermochemical model for the effect of clay diagenesis on shale/mudstone permeability based on precipitation of clay minerals in pore networks and exponential decreases in permeability (Bjorkum and Nadeau, 1998) have been confirmed by subsurface studies (Nadeau et al., in press). These results have important implication for modeling fluid flow at the basin and field scale, including: 1. overpressure development; 2. hydrocarbon migration; 3. fluid flow through oil columns, shale top seals, and possible controls on biodegradation processes.