A method of monitoring acoustic energy using distributed acoustic sensing. The method involves supplying a fluid flow at different pressures and sensing fluid flow characteristics in at least one location at each pressure. The data may be processed to provide a fluid resistance value related to a particular fluid flow at each location, collectively forming a fluid resistance index (FRI). The method may include following the initial fluid flow with a process flow, which may then be followed by another fluid flow. The flow characteristics of the latter fluid flow may be measured and compared with the initial fluid flow, providing a measure of the success of the process flow. In application, this method may be used to enhance downhole operations, including acid stimulation treatments.