Formation of Traveling Liquid Bridges between Matrix Blocks: Modeling and Simulation

It is widely accepted that under reservoir conditions there exists some degree of block to block interaction that may result in capillary continuity. The formation of liquid bridges causing capillary continuity between blocks will significantly affect ultimate recovery. In this work a mechanistic model with original thought from hydrology for a given steady feeding volumetric flow rate from an upper block (under both gravity and matrix capillary pressure effects) is developed which considers the formation, growth and detachment of pendant liquid droplets perpendicular to the horizontal fracture (assuming to be smooth and parallel walled) between blocks. The length of detached liquid droplet is observed to be weakly related to the flow rate but it increases as the fracture capillary pressure increases. By neglecting the impact of the flow rate, the simple relation is derived for determination of the length of detached pendant droplet which depends on the fracture capillary pressure, liquid density and the gravitational acceleration. Comparison between the horizontal fracture aperture size and the length of detached pendant liquid droplet is then used to evaluate the formation of traveling liquid bridge between upper and lower blocks.