A flow sensor is incorporated into a junk basket to sense a flow stoppage
due to a plugged screen or plugged cuttings ports in a mill. The sensor
triggers a signal to the surface to warn personnel that a problem exists
before the equipment is damaged. The sensor signal to the surface can
take a variety of forms including mud pulses, a detectable pressure
buildup at the surface, electromagnetic energy, electrical signal on hard
wire or radio signals in a wifi system to name a few options. Surface
personnel can interrupt the signal to take corrective action that
generally involves pulling out of the hole or reverse circulating to try
to clear the screen or mill cuttings inlets. Other variables can be
measured such as the volume or weight or rate of change of either and a
signal can be sent to the surface corresponding to one of those variables
to allow them to be detected at the surface in near real time.