GB961901A - Position selector device for wells - Google Patents

Abstract

961,901. Locating magnetic bodies. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N. V. June 20, 1962 [June 22, 1961], No. 23770/62. Heading G1N. [Also in Divisions E1 and G4] A position-selector device 34 adapted to pass through a well pipe (not shown) comprises a body 37, 38, 39 latching means 71 carried within the body, a counter mechanism 43 connected to actuate the latching means at a preselected positon in the pipe, and magnetic-type counter-actuating means 40, 41 carried by the body and adapted for stepwise actuation of the counter mechanism in response to movement past marker means spaced along the pipe and having a magnetic permeability different from that of the rest of the pipe. The device is assembled with a well tool or instrument 32 and motor swab elements 33, 33a, parts of the assembly being connected by flexible joints 35, 35a, 36, 36a. The assembly is pumped down the well pipe which includes marker means comprising non-magnetic sleeves and has an enlargement beneath each sleeve. The counter actuating means comprises a core 40 and coil 41 connected to actuate the counter 43 which is pre-set to cause a relay 44 to pass current from a battery 45 to an explosive charge 47 when the device has passed the number of sleeves corresponding to the preselected positon and enlargement. Detonation of the charge moves a piston 51 to the position shown in Fig. 4 forcing a valve 53 so that the well fluid within the pipe passes through a port 55, groove 54, and duct 60 to a space 61 beneath a piston 57. The resultant upward movement of the piston 57 moves a blocking member 70 upwardly, the rate of movement increasing after a port 66 communicates with a passage 63. After the blocking member moves, the latching dog 71 pivots outwardly to engage the preselected enlargement in the pipe. The pumping pressure on the assembly is reversed so that the parts of a joint 76, 77 separate to permit the swab elements end parts 37, 38 of the device to be pumped from the well. In a modification the blocking member and its piston are moved directly by the force of the explosion of the charge with or without assistance from the pressure of the well fluid. The device may be operated in a well pipe in which the upper sleeve is dispensed with, and the pipe at the lowest enlargement may be shaped to prevent further downward movement of the device.