VALIDATION EXPERIMENTS IN LABORATORY ON HIGH VISCOSITY FLUID INJECTION TEST TO CHARACTERIZE FRACTURE PROPERTIES

We proposed high-viscosity fluid injection tests to evaluate flow dimension and porosity in fractures. Experiments were conducted to evaluate the method by injecting high-viscosity methylcellulose solution at a constant rate into stainless steel tubing and model fractures. In stainless steel tube experiments, injection pressure increased linearly with time and the pressure gradient was dependent on tube diameter. In model fractures, injection pressure increased logarithmically with time and the pressure gradient was controlled by fracture width. Changes of tube diameter and fracture width could be estimated from the derivative of the pressure. High-viscosity fluid injection tests were able to identify the flow dimension (e. g. one- and two-dimensional flow) and quantify features controlling porosity, such as tube diameter and fracture width. Our results confirm the applicability of high-viscosity fluid injection tests to determine fracture properties in laboratory experiments.