DISSOLUTION-INDUCED PREFERENTIAL FLOW IN A LIMESTONE FRACTURE

Flow in a rock fracture is surprisingly sensitive to the evolution of flow paths that develop as a result of dissolution. Net dissolution may either increase or decrease permeability uniformly within the fracture, or may form a preferential flow path through which most of the injected fluid flows, depending on the prevailing ambient mechanical and chemical conditions. A flow-through test was completed on an artificial fracture in limestone at room temperature under ambient confining stress of 3.5 MPa. Based on the X-ray Computed Tomography characterizations, a flow path-dependent flow model was developed to simulate the evolution of flow paths within the fracture and its influence on the overall flow behaviors of the injected fluid in the fracture.