Abstract: A plunger has a transmitter that produces signals as the plunger moves in a well. The signals are pulses that are produced at a constant interval. The plunger signals are detected and used to determine the location, direction of travel and speed of the plunger in the well. In addition, the location or height of the liquid level is detected as is the arrival of the plunger at the well bottom.

Abstract: A stress and torque reducing tool has a plunger that reciprocates inside of a body. The tool is connected between the pump and the sucker rod string and reduces stress transmitted therebetween. The body has upper and lower fluid ports to allow the ingress and egress of well fluids from the body as the plunger reciprocates. If the tool fails, it typically does so by the body breaking into two parts, namely the upper body and lower body, at the upper fluid ports. The upper end of the plunger is provided with a fishing neck. Thus, upon failure of the body at the upper fluid ports, the fishing neck is exposed and can receive a fishing tool for retrieval of the tool and the pump.