Increase power output of a downhole tool generator assembly
An apparatus configured to be positioned on a tubular string in a wellbore formed in a subsurface formation. The apparatus comprises a generator assembly disposed on the tubular string and configured to output power to a downhole tool. The generator assembly includes a first generator configured to output a first power to the downhole tool. The generator includes a second generator configured to function as an exciter for the first generator.
1. An apparatus configured to be positioned on a tubular string in a wellbore formed in a subsurface formation, the apparatus comprising:
a generator assembly disposed on the tubular string and configured to output power to a downhole tool, the generator assembly including,
a first generator configured to output a first power to the downhole tool; and
a second generator having one or more permanent magnets and configured to function as an exciter for the first generator.
2. The apparatus of claim 1 , the first generator comprising:
a first turbine;
a first rotor disposed on the first turbine;
one or more field coils at least partially surrounding the first rotor; and
a first stator configured to output the first power to the downhole tool.
3. The apparatus of claim 2 , wherein outputting the first power comprises rotating the first rotor, via a flow of fluid interacting with the first turbine as the fluid flows through the tubular string, to induce a first current on the first stator.
4. The apparatus of claim 2 , the second generator comprising:
a second turbine;
a second rotor including the one or more permanent magnets, the second rotor disposed on the second turbine; and
a second stator configured to output a second power to the one or more field coils at least partially surrounding the first rotor.
5. The apparatus of claim 4 , wherein outputting the second power comprises rotating the second rotor, via a flow of fluid interacting with the second turbine as the fluid flows through the tubular string, to induce a second current on the second stator.
6. The apparatus of claim 4 , wherein the second generator increases a magnetic field of the first rotor via the second power output from the second stator.
7. The apparatus of claim 1 , wherein the downhole tool includes an inflow control device.
8. The apparatus of claim 1 , further comprising:
a rectifier, wherein the rectifier rectifies the first power output by the first generator to the downhole tool.
9. A system comprising:
a tubular string positioned in a wellbore positioned in a subsurface formation;
a downhole tool disposed on the tubular string; and
a generator assembly disposed on the tubular string and configured to output power to the downhole tool, the generator assembly including,
a first generator configured to output a first power to the downhole tool; and
a second generator having one or more permanent magnets and configured to function as an exciter for the first generator.
10. The system of claim 9 , the first generator comprising:
a first turbine;
a first rotor disposed on the first turbine;
one or more field coils surrounding the first rotor; and
a first stator configured to output the first power to the downhole tool.
11. The system of claim 10 , wherein outputting the first power comprises rotating the first rotor, via a flow of fluid interacting with the first turbine as the fluid flows through the tubular string, to induce a first current on the first stator.
12. The system of claim 10 , the second generator comprising:
a second turbine;
a second rotor including the one or more permanent magnets, the second rotor disposed on the second turbine; and
a second stator configured to output a second power to the one or more fields coil surrounding the first rotor.
13. The system of claim 12 , wherein outputting the second power comprises rotating the second rotor, via a flow of fluid interacting with the second turbine as the fluid flows through the tubular string, to induce a second current on the second stator.
14. The system of claim 12 , wherein the second generator increases a magnetic field of the first rotor via the second power output from the second stator.
15. The system of claim 9 , wherein the downhole tool includes an inflow control device.
16. A method comprising:
positioning a tubular string in a wellbore formed in a subsurface formation, wherein a downhole tool is disposed on the tubular string; and
outputting power, via a generator assembly disposed on the tubular string, to the downhole tool, the generator assembly including,
a first generator configured to output a first power to the downhole tool; and
a second generator having one or more permanent magnets and configured to increase the first power by increasing a magnetic field of a first rotor of the first generator.
17. The method of claim 16 , the first generator comprising:
a first turbine, wherein the first rotor is disposed on the first turbine;
one or more field coils surrounding the first rotor; and
a first stator configured to output the first power to the downhole tool.
18. The method of claim 17 , wherein outputting the first power comprises rotating the first rotor, via a flow of fluid interacting with the first turbine as the fluid flows through the tubular string, to induce a first current on the first stator.
19. The method of claim 17 , the second generator comprising:
a second turbine;
a second rotor including the one or more permanent magnets, the second rotor disposed on the second turbine; and
a second stator configured to output a second power to the one or more field coils surrounding the first rotor.
20. The method of claim 19 , wherein outputting the second power comprises rotating the second rotor, via a flow of fluid interacting with the second turbine as the fluid flows through the tubular string, to induce a second current on the second stator.