Remotely operated downhole switching apparatus
AssigneeTRW Inc.
InventorRobert L. Hyde
Life of this patent
Estimating the term…
Abstract
A remotely operated downhole switching apparatus, particularly adapted to selectively connect a downhole device such as a sensor circuit to a cable which supplies power to a downhole motor includes a switch for connecting the downhole device to a neutral node of the motor, a latch coil responsive to a latching signal carried by the cable for closing the switch, and a delatch coil connected to the cable through a frequency responsive circuit which is responsive to a delatching signal carried by the cable for passing current through the delatch coil. A diode connected to the delatch coil prevents current flow through the delatch coil in a direction which causes the switch to close. An AC signal may be employed for closing the switch, and a voltage pulse may be employed for opening the switch.
Claims17
A downhole switching apparatus for controlling the connection of a downhole device to a cable which carries energizing current to a downhole motor, comprising switch means connected between the downhole device and the cable, the switch means having a closed position at which the downhole device is connected to the cable and having an open position at which the downhole device is disconnected from the cable, latching means responsive to a latching signal carried by the cable for closing the switch means, delatching means responsive to current flow of a predetermined direction therethrough for opening the switch means, frequency responsive means responsive to a delatching signal carried by the cable and capable of passing to the delatching means a current in said predetermined direction and a current in the opposite direction, and diode means connected in parallel with the delatching means for preventing current in said opposite direction from passing through the delatching means.
A downhole switching apparatus for controlling the connection of a downhole device to a cable which carries energizing current to a downhole motor, comprising switch means connected between the downhole device and the cable, the switch means having a closed position at which the downhole device is connected to the cable and having an open position at which the downhole device is disconnected from the cable, latching means responsive to a latching signal carried by the cable for closing the switch means, delatching means responsive to current flow of a predetermined direction therethrough for opening the switch means, frequency responsive means responsive to a delatching signal carried by the cable and capable of passing to the delatching means a current in said predetermined direction and a current in the opposite direction, and means connected to the delatching means for preventing current in said opposite direction from passing through the delatching means, wherein the latching means and the delatching means comprise a latch and a delatch coil, respectively, wherein the preventing means comprises a diode, wherein the delatching means further comprises a resistor connected in series with the delatch coil, and the diode is connected in parallel with the resistor and the delatch coil.
A downhole switching apparatus for controlling the connection of a downhole device to a cable which carries energizing current to a downhole motor, comprising switch means connected between the downhole device and the cable, the switch means having a closed position at which the downhole device is connected to the cable and having an open position at which the downhole device is disconnected from the cable, latching means responsive to a latching signal carried by the cable for closing the switch means, delatching means responsive to current flow of a predetermined direction therethrough for opening the switch means, frequency responsive means responsive to a delatching signal carried by the cable and capable of passing to the delatching means a current in said predetermined direction and a current in the opposite direction, and means connected to the delatching means for preventing current in said opposite direction from passing through the delatching means, wherein the latching means and the delatching means comprise a latch and a delatch coil, respectively, wherein the preventing means comprises a diode, and further comprising another diode connected to the latch coil for permitting current flow through the latch coil only in a predetermined direction.
A downhole switching apparatus for controlling the connection of a downhole device to a cable which carries energizing current to a downhole motor, comprising switch means connected between the downhole device and the cable, the switch means having a closed position at which the downhole device is connected to the cable and having an open position at which the downhole device is disconnected from the cable, latching means responsive to a latching signal carried by the cable for closing the switch means, delatching means responsive to current flow of a predetermined direction therethrough for opening the switch means, frequency responsive means responsive to a delatching signal carried by the cable and capable of passing to the delatching means a current in said predetermined direction and a current in the opposite direction, and means connected to the delatching means for preventing current in said opposite direction from passing through the delatching means, wherein the latching means and the delatching means comprise a latch and a delatch coil, respectively, wherein the preventing means comprises a diode, and further comprising another frequency responsive means connected to the latch coil for passing the latching signal to the latch coil and for blocking the delatching signal.
A downhole switching apparatus for controlling the connection of a downhole device to a cable which carries energizing current to a downhole motor, comprising switch means connected between the downhole device and the cable, the switch means having a closed position at which the downhole device is connected to the cable and having an open position at which the downhole device is disconnected from the cable, latching means responsive to a latching signal carried by the cable for closing the switch means, delatching means responsive to current flow of a predetermined direction therethrough for opening the switch means, frequency responsive means responsive to a delatching signal carried by the cable and capable of passing to the delatching means a current in said predetermined direction and a current in the opposite direction, and means connected to the delatching means for preventing current in said opposite direction from passing through the delatching means, wherein the latching means and the delatching means comprise a latch and a delatch coil, respectively, wherein the preventing means comprises a diode, wherein said switch means comprises a normally open magnetically operated switch and a permanent magnet for holding the switch in closed position once it is closed, and wherein said latch and delatch coils are arranged to produce magnetic fields for respectively closing and opening the switch.
A downhole switching apparatus for controlling the connection of a downhole device to a cable which carries energizing current to a downhole motor, comprising switch means connected between the downhole device and the cable, the switch means having a closed position at which the downhole device is connected to the cable and having an open position at which the downhole device is disconnected from the cable, latching means responsive to a latching signal carried by the cable for closing the switch means, delatching means responsive to current flow of a predetermined direction therethrough for opening the switch means, frequency responsive means responsive to a delatching signal carried by the cable and capable of passing to the delatching means a current in said predetermined direction and a current in the opposite direction, and means connected to the delatching means for preventing current in said opposite direction from passing through the delatching means, wherein said frequency responsive means comprises an inductor and a capacitor connected in series to form a series resonant circuit, the values of the inductor and the capacitor being selected to provide a resonant frequency such that the impedance of the series resonant circuit is high at the frequency of the downhole motor current and at the frequency of the latching signal, and is low at the frequency of the delatching signal.
Dependencies are inferred from the claim text.