MAGNETIC THRUST LOAD SUPPORT FOR DOWNHOLE-TYPE SYSTEM
A downhole-type system includes a rotatable shaft; a sensor that can sense an axial position of the shaft and generate a first signal corresponding to the axial position of the shaft; a controller coupled to the sensor, in which the controller can receive the first signal generated by the sensor, determine an amount of axial force to apply to the shaft to maintain a target axial position of the shaft, and transmit a second signal corresponding to the determined amount of axial force; and multiple magnetic thrust bearings coupled to the shaft and the controller, in which each magnetic thrust bearing can receive the second signal from the controller and modify a load, corresponding to the second signal, on the shaft to maintain the target axial position of the shaft.
1 . A downhole-type system comprising:
a shaft;
a sensor configured to:
sense an axial position of the shaft, and
generate a first signal corresponding to the axial position of the shaft;
a controller coupled to the sensor, the controller configured to:
receive the first signal generated by the sensor,
determine an amount of axial force to apply to the shaft to maintain a target axial position of the shaft, and
transmit a second signal corresponding to the determined amount of axial force; and
a plurality of magnetic thrust bearings coupled to the shaft and the controller, each magnetic thrust bearing configured to:
receive the second signal from the controller, and
modify a load, corresponding to the second signal, on the shaft to maintain the target axial position of the shaft.
2 . The system of claim 1 , wherein the plurality of magnetic thrust bearings is sealed from a downhole environment.
3 . The system of claim 1 , wherein the plurality of magnetic thrust bearings is lubricant-free.
4 . The system of claim 1 , wherein critical components of the plurality of magnetic thrust bearings are sealed from a downhole environment.
5 . The system of claim 1 , wherein the load is transmitted on the shaft using a coupling.
6 . The system of claim 5 , wherein the plurality of magnetic thrust bearings is located in an isolated environment, and at least a portion of the load is transmitted using a magnetic coupling.
7 . The system of claim 1 , wherein the plurality of magnetic thrust bearings is coupled to the controller in parallel, in series, or combinations thereof.
8 . The system of claim 1 , wherein the controller is configured to multiplex a plurality of signals, the second signal comprising the plurality of signals.
9 . The system of claim 1 , wherein the controller is located topside.
10 . The system of claim 1 , wherein the controller is located at least 500 meters away from the plurality of magnetic thrust bearings.
11 . The system of claim 1 , wherein the sensor is located in a downhole location, and electronics of the sensor are located topside.
12 . The system of claim 1 , wherein each magnetic thrust bearing comprises:
an actuator surrounding the shaft, the actuator configured to generate a magnetic field in response to receiving an electric current; and
a target surrounding the shaft, the target configured to generate an axial force in response to the generated magnetic field.
13 . The system of claim 12 , wherein the actuator comprises a plurality of arcuate portions defining a respective plurality of openings that complement each other to define an annulus larger than an outer diameter of the rotatable shaft.
14 . The system of claim 13 , wherein the plurality of arcuate portions comprises a first, semi-circular arcuate portion and a second, semi-circular arcuate portion.
15 . The system of claim 13 , wherein the plurality of magnetic thrust bearings comprise a respective plurality of actuators coupled by an electrical winding configured to pass an electric signal in response to which the plurality of actuators generates a respective plurality of magnetic fields.
16 . The system of claim 13 , wherein each magnetic thrust bearing comprises an actuator, each actuator coupled to their respective magnetic thrust bearing by an electrical winding configured to pass an electric signal in response to which each actuator generates a respective magnetic field, and the electrical windings are connected together.
17 . The system of claim 13 , wherein each actuator comprises a fuse configured to electrically fail in response to an increase in the electric signal beyond an electric signal threshold through a portion of the winding wound around each actuator.
18 . The system of claim 17 , wherein the fuse is configured to be reset from a remote location.
19 . A method comprising:
during rotation of a shaft of a downhole-type wellbore system, the shaft axially levitated by a plurality of magnetic thrust bearings,
transmitting, by a sensor, a first signal corresponding to an axial position of the rotating shaft;
determining, by a controller, an amount of axial force to apply to the rotating shaft to maintain axial levitation of the rotating shaft based on the first signal;
transmitting, by the controller, a second signal that corresponds to the determined amount of axial force to the plurality of magnetic thrust bearings; and
applying, by the plurality of magnetic thrust bearings, the amount of axial force on the rotating shaft to maintain the axial levitation of the rotating shaft based on the second signal.
20 . The method of claim 19 , wherein the plurality of magnetic thrust bearings is sealed from a downhole environment.
21 . The method of claim 19 , wherein the plurality of magnetic thrust bearings is lubricant-free.
22 . The method of claim 19 , wherein the plurality of magnetic thrust bearings is coupled to the controller in parallel, in series, or combinations thereof.
23 . The method of claim 19 , further comprising:
generating, by an actuator of one of the plurality of magnetic thrust bearings, a magnetic field in response to receiving an electric current; and
generating, by a target of one of the plurality of magnetic thrust bearings, an axial force in response to the generated magnetic field.
24 . The method of claim 23 , wherein the actuator comprises a plurality of arcuate portions defining a respective plurality of openings that complement each other to define an annulus larger than an outer diameter of the rotatable shaft.
25 . The method of claim 24 , wherein the plurality of arcuate portions comprises a first, semi-circular arcuate portion and a second, semi-circular arcuate portion.
26 . The method of claim 24 , wherein the plurality of magnetic thrust bearings comprises a respective plurality of actuators coupled by an electric winding configured to pass an electric signal in response to which the plurality of actuators generates a respective plurality of magnetic fields.
27 . The method of claim 26 , further comprising, by a fuse of one of the plurality of actuators, electrically failing in response to an increase in the electric signal beyond an electric signal threshold through a portion of the winding wound around each actuator.
28 . A downhole-type system comprising:
a shaft;
a sensor configured to transmit a first signal that corresponds to an axial position of the shaft;
a controller coupled to the sensor and configured to determine, based on the first signal, an amount of axial force to apply to the shaft to maintain axial levitation of the shaft; and
a plurality of magnetic thrust bearings coupled to the shaft and the controller, each magnetic thrust bearing configured to modify a load on the shaft to maintain an axial position of the shaft based on a second signal that corresponds to the determined amount of axial force.