Patent ID: 7669651

Claim:
A system for monitoring pumping conditions in a petroleum well, said system comprising in combination: at least one signaling device interposed at an intermediate position in coextensive strings of sucker rod and tubing; the signaling device including a trigger element, mounted in the sucker rod string and movable therewith throughout its reciprocation span; a piston element encompassing the trigger element and spaced therefrom; a cylinder about the piston element and attached between tubing sections, the cylinder retaining the piston element in sliding relation; a resilient sleeve coupled to the interior of the piston and dimensioned to resiliently and peripherally engage the trigger element as the trigger element reciprocates with the sucker rod, the length of the sleeve being short relative to the reciprocation span of the sucker rod; a compression spring engaging the bottom end of the piston and coupled fixedly to the cylinder at its lower end; the piston being driven down against the compression spring by the trigger element and released when the trigger element slides through the sleeve; wherein the sensor element also includes an impact element configured to generate a signal transmissible in fluid to the wellhead when impacted by the piston, the signal differing when the signaling device is in the presence of fluid relative to when there is no fluid.