Electrical system and method for selective control of downhole devices
AssigneeHalliburton Energy Services, Inc.
InventorIbrahim El Mallawany
Life of this patent
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Abstract
A method of actuating a selected electrically powered device such as a solenoid operated valve (SOV) among a plurality of electrically powered devices coupled between a first conductor and second conductor includes applying a high voltage differential between the first conductor and the second conductor, the high voltage being at least as high as the breakover voltage of a switching thyristor coupled to the selected electrically powered devices. The method also includes applying a low voltage differential between the first conductor and the second conductor after applying the high voltage, the low voltage being lower than the breakover voltage of any switching thyristor coupled to the plurality of electrically powered devices.
Claims18
An electrical system for selective control of downhole devices, comprising:
- a first conductor;
- a second conductor;
- a first electrically powered downhole device coupled between the first conductor and the second conductor
- a first switching thyristor coupled between the first conductor and the second conductor in series with the first electrically powered downhole device;
- a second electrically powered device coupled between the first conductor and the second conductor parallel to the first electrically powered device;
- a second switching thyristor coupled to the second electrically powered device and comprising a lower breakover voltage than the first switching thyristor;
- and
- a voltage delay device coupled to the second switching thyristor and configured to prevent a voltage from being applied to the second switching thyristor for a first amount of time.
A method of selectively controlling a plurality of valves, comprising:
- applying a first voltage in a first direction at a start time to an electrical valve control system, the electrical valve control system comprising a plurality of electrically powered devices coupled between a first conductor and a second conductor;
- actuating a first electrically powered device of the plurality of electrically powered devices with the first voltage after a first voltage delay duration since the start time, wherein the first electrically powered device is coupled to a switching thyristor having a breakover voltage less than the first voltage;
- reducing the first voltage to a low voltage after actuation of the first electrically powered device and before a second voltage delay duration has elapsed since the start time;
- and
- wherein a second electrically powered device of the plurality of electrically powered devices will not actuate before the second voltage delay duration has elapsed, and the low voltage is lower than a breakover voltage of the second electrically powered device.
A method of actuating a selected electrically powered device among a plurality of electrically powered devices, each of the electrically powered devices coupled in series to a unique combination of a switching thyristor and a voltage delay device between a first conductor and second conductor, comprising:
- applying a high voltage differential between the first conductor and the second conductor, the high voltage being at least as high as the breakover voltage of a selected switching thyristor coupled to the selected electrically powered device;
- and
- reducing the high voltage differential to a low voltage differential between the first conductor and the second conductor when the selected electrically powered device is actuated, the low voltage being lower than the breakover voltage of the switching thyristors coupled to the plurality of electrically powered devices, wherein the selected electrically powered device is the first of the plurality of electrically powered devices to be actuated by the high voltage differential.
Dependencies are inferred from the claim text.