Monitoring subsurface fluid flow is important in mapping hydraulic fractures and identifying flow channels in reservoirs. A new monitoring technique is proposed whereby fluid is injected with smart actuators capable of organising their pulses to create a combined output with a higher proportion of energy at low frequencies. Ideally, the best results occur when actuators are sequentialised so each next actuator emits its pulse immediately after the previous actuator. The low frequency energy content achieved using sequentialisation is much higher than that achieved with a random distribution of pulses, but is relatively insensitive to practical errors in scheduling and irregular attenuations of amplitudes. Simulations show that actuators can be self-organised into a sequential state by monitoring other actuators’ pulses using the algorithm presented in this paper.
An Overview: Special Issue on “The Slow Subsurface Fluid Flow Processes (Part I): Theory, Model, and Physical Properties Estimation”
