Design, Construction, and Testing of a Large-Scale, Radial Fracture Flow Model

Materials and procedures used in previous laboratory studies of flow in fractures were reviewed. Based on this review, a 3-m-high by 1.5-m-diameter cylindrical radial flow model with a single horizontal fracture was designed and constructed out of concrete. The fracture was created by placing a sheet of geotextile between the top and bottom halves of the cylinder during pouring of the concrete. Twenty-eight piezometers were cast in-place in the fracture plane, and displacement transformers were installed both on the circumference of the cylinder and in the wellbore to measure fracture deformation. The model also incorporated features designed to allow withdrawal and injection tests to be conducted with different flow boundary conditions, applied loads, and wellbore diameters. This laboratory setup was used to investigate flow and deformation in the immediate vicinity of a vertical well intersecting a single rough, deformable, horizontal fracture at flow rates of practical interest to the geotechnical and petroleum industries.