A method of determining osmotic pressure for low-clay shale with different salt ions considering effect of dynamic permeability on flow

Fluid penetration from water-based drilling fluids into shale formations results in swelling and subsequent borehole instability. Generally, inorganic or organic salts are used to generate necessary chemical osmotic pressure to inhibit shale hydration and swelling. However, the relationship between salt ions and shale osmotic pressure is not clear. In this study, a dynamic model is proposed to determine osmotic pressure of Longmaxi shale,...