Borehole Stability in Shales

摘要: Downhole mud/shale interaction can only be properly understood if rock mechanical, shale hydration, and fluid transport phenomena are taken into account. This paper presents a review of Koninklijke Shell E P Laboratorium's research on borehole stability in shales. Mechanisms relevant to stability, including pore pressure penetration (the gradual increase resulting from high mud weight), capillary threshold pressures, compressive tensile failure, postfailure stabilization, hydration stress, inhibition, osmotic discussed. The authors attempt integrate these mechanisms comprehensive model for behavior.