MANAGING POWER CONSUMPTION IN A DOWNHOLE ROBOT
In one implementation, a downhole robot includes a housing, electrically-powered equipment configured to perform operations of the downhole robot, a power source disposed inside the housing, the power source coupled by a current flow path to provide electrical current to power to the electrically-powered equipment, and a resettable latch disposed inside the housing. The resettable latch is configured to either interrupt flow of electrical along the current flow path or allow current to flow along the current flow path in response to a signal that wirelessly penetrates the housing.
1 . A downhole robot comprising:
a housing;
electrically-powered equipment configured to perform operations of the downhole robot;
a power source disposed inside the housing, the power source coupled by a current flow path to provide electrical current to power to the electrically-powered equipment; and
a resettable latch disposed inside the housing, wherein the resettable latch is configured to either interrupt flow of electrical along the current flow path or allow current to flow along the current flow path in response to a signal that wirelessly penetrates the housing.
2 . The downhole robot of claim 1 , wherein:
the resettable latch is magnetically-resettable or acoustically-resettable; and
the signal comprises a magnetic field or an acoustic pulse.
3 . The downhole robot of claim 1 , wherein the electrically-powered equipment includes at least one of:
a propulsion system; or
a communication system; or
a sensor system.
4 . The downhole robot of claim 1 , wherein the housing comprises a housing portion disposed in vicinity of the resettable latch, wherein the housing portion is formed from material that has a relatively lower permeability than a remainder of the housing.
5 . The downhole robot of claim 1 , wherein the downhole robot comprises:
a transistor switch, wherein the resettable latch is configured to latch the transistor switch in a conductive state in response to the signal that wirelessly penetrates the housing.
6 . The downhole robot of claim 5 , wherein the downhole robot comprises isolated gate drive circuitry coupled to drive the transistor switch.
7 . The downhole robot of claim 1 , wherein the resettable latch is configured to reversibly allow return current to flow through the resettable latch to the power source in response to the signal that wirelessly penetrates the housing.
8 . The downhole robot of claim 1 , wherein the resettable latch is powered by a second power source that differs from the power source.
9 . The downhole robot of claim 1 , wherein the current flow path passes through the resettable latch.
10 . The downhole robot of claim 1 , wherein:
the electrically-powered equipment comprises a first subsystem of the downhole robot; and
wherein the downhole robot further comprises:
a second electrically-powered subsystem configured to perform operations of the downhole robot, wherein the power source is coupled by a second current flow path to provide electrical current to power to the second electrically-powered subsystem, and
a second resettable latch disposed inside the housing and configured to reversibly allow current to flow along the second current flow path in response to a signal that wirelessly penetrates the housing.
11 . The downhole robot of claim 1 , wherein the housing is configured to withstand ten megapascals of differential pressure or more.
12 . A method performed by a downhole robot that comprises a power source disposed inside a housing of the downhole robot, the method comprising:
receiving, at a latch also disposed within the housing, a signal that wirelessly penetrates the housing; and
either forming or interrupting a current flow path that couples the power source and equipment of the downhole robot in response to the signal.
13 . The method of claim 12 , wherein receiving the signal comprises receiving a signal of sufficient strength to actuate a mechanical switch, wherein the current flow path is either formed or interrupted in response to the receipt of a magnetic or acoustic signal.
14 . The method of claim 12 , wherein receiving the signal comprises closing or opening a magnetically-actuatable reed switch of the latch.
15 . The method of claim 12 , wherein either forming or interrupting the current flow path comprises forming or interrupting a return current flow path.
16 . The method of claim 15 , wherein the return current flow path passes through the latch.
17 . The method of claim 12 , wherein forming or interrupting the current flow path comprising biasing a transistor switch coupled such that the current flow path flows through main terminals of the transistor switch.
18 . The method of claim 17 , wherein biasing the transistor switch comprises biasing the transistor switch using isolated gate drive circuitry that galvanically isolates a control terminal of the transistor switch from an input to the isolated gate drive circuitry.
19 . The method of claim 12 , wherein the equipment of the downhole robot includes at least one of:
a propulsion system; or
a communication system; or
a sensor system.
20 . The method of claim 12 , further comprising:
receiving, at a second latch also disposed within the housing, a signal that wirelessly penetrates the housing; and
either forming or interrupting a second current flow path that couples the power source and second equipment of the downhole robot in response to the signal.