Variable-output generator for downhole power production

Patent metadata

Field	Value
Publication number	US-9356497-B2
Application number	US-201214117288-A
Country	US
Kind code	B2
Filing date	Aug 30, 2012
Priority date	Aug 30, 2012
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

Methods and systems of downhole power generation are disclosed. The method includes the steps of rotating a magnet assembly about an axis relative to a coil assembly at a first rotational velocity, axially moving the magnet assembly to a first position on the axis with a configurable actuator so as to adjust a magnetic interaction between the magnet assembly and the coil assembly, and providing a power output from the coil assembly at a first power output level corresponding to the first position while the magnet assembly is rotating at the first rotational velocity.

First claim

The invention claimed is:

1. A method of downhole power generation, comprising:
rotating a magnet assembly about an axis relative to a coil assembly at a first rotational velocity, the magnet assembly and the coil assembly being positioned within a housing and the magnet assembly being coupled to a plunger movable within the housing;
axially moving the magnet assembly in a first direction to a first position on the axis with a configurable actuator coupled to the housing at one end of the configurable actuator and coupled to the plunger at an opposing end of the configurable actuator;
adjusting a magnetic interaction between the magnet assembly and the coil assembly as the magnet assembly moves to the first position;
biasing the magnet assembly in a second direction opposite the first direction with a biasing element coupled to the housing and the plunger; and
providing a power output from the coil assembly at a first power output level corresponding to the first position while the magnet assembly is rotating at the first rotational velocity.

2. The method of downhole power generation of claim 1 , further comprising providing a fluid at a selected pressure to the configurable actuator and thereby applying a force to the magnet assembly in the first direction, the force having a magnitude corresponding to the selected pressure.

3. The method of downhole power generation of claim 1 , wherein the magnet assembly is movable on the axis within a range of positions, the range comprising an engaged position at one end of the range and a disengaged position at the other end of the range, and wherein the biasing element is configured to urge the magnet assembly toward one of the engaged end and the disengaged end and the actuator is configured to urge the magnet assembly toward the other of the engaged end and the disengaged end.

4. The method of downhole power generation of claim 1 , further comprising:
rotating the magnet assembly at a second rotational velocity, the second rotational velocity being different than the first rotational velocity;
axially moving the magnet assembly to a second position on the axis with respect to the coil assembly; and
maintaining the power output from the coil assembly at the first power output level while the magnet assembly is rotating at the second rotational velocity.

5. The method of downhole power generation of claim 1 , wherein rotating the magnet assembly about the axis comprises rotating an input shaft that is coincident with the axis using input power from a power source, wherein the magnet assembly is coupled to the input shaft such that the magnet assembly rotates synchronously with the input shaft while being able to translate axially along the axis.

6. The method of downhole power generation of claim 5 , wherein the power source comprises a downhole motor, the method further comprising driving the downhole motor with a flow of mud.

7. The method of downhole power generation of claim 1 , further comprising:
providing the power output from the coil assembly to a downhole electrical module.

8. The method of downhole power generation of claim 7 , further comprising:
communicating a control signal with the downhole electrical module to a power control module communicably coupled to the coil assembly, the control signal comprising information related to an amount of power required to operate one or more downhole equipment and/or tools associated with the downhole electrical module;
communicating a command signal corresponding to the control signal to the configurable actuator with the power control module; and
moving the magnet assembly to a selected axial position on the axis and thereby providing the amount of power required to operate the one or more downhole equipment and/or tools.

9. A downhole power generator, comprising:
a coil assembly arranged about a longitudinal axis within a housing and having a power output exhibiting a power output level;
a magnet assembly movably arranged within the housing with respect to the coil assembly and coupled to a plunger axially movable within the housing, the magnet assembly being configured to rotate about the longitudinal axis at a rotational velocity and to translate axially along the longitudinal axis within a range of positions;
an actuator coupled to the housing at one end of the actuator and to the plunger at an opposing end of the actuator; and
a biasing element coupled to the housing and the plunger,
wherein the actuator is configured to urge the magnet assembly in at least a first direction along the longitudinal axis and further configured to move the magnet assembly to any axial position within the range,
wherein the biasing element biases the magnet assembly in a second direction opposite the first direction, and
wherein the power output level depends at least partially on an axial position of the magnet assembly.

10. The power generator of claim 9 , wherein the magnet assembly comprises a plurality of magnets, and wherein none of the plurality of magnets is movable relative to each other.

11. The downhole power generation system of claim 9 , wherein the power output level corresponds to a first power output level when the magnet assembly is rotating at a first rotational velocity and disposed at a first axial position within the range.

12. The downhole power generation system of claim 11 , wherein the power output level also corresponds to the first power output level when the magnet assembly is rotating at a second rotational velocity and disposed at a second axial position within the range.

13. The downhole power generation system of claim 11 , wherein the power output level corresponds to a second power output level when the magnet assembly is rotating at the first rotational velocity and disposed at a second position within the range.

14. The power generator of claim 9 , wherein the range comprises an engaged position at one end of the range and a disengaged position at an opposing end of the range, the biasing element being configured to urge the magnet assembly away from the engaged position and toward the disengaged position.

15. The power generator of claim 9 , wherein the range comprises an engaged position at one end of the range and a disengaged position at an opposing end of the range, the biasing element being configured to urge the magnet assembly away from the disengaged position and toward the engaged position.

16. The power generator of claim 9 , further comprising an input shaft coincident with the longitudinal axis and configured to rotate at the rotational velocity, wherein the magnet assembly is disposed on the input shaft and configured to synchronously rotate with the input shaft, the input shaft being driven by a power source.

17. The power generator of claim 16 , wherein the power source comprises a turbine driven by a flow of mud.

18. The power generator of claim 9 , further comprising:
a downhole electrical module communicably coupled to the power output; and
a power control module communicably coupled to the downhole electronics module via the power output, the downhole electronics module being configured to communicate to the power control module a control signal comprising information related to an amount of power required to operate one or more downhole equipment and/or tools associated with the downhole electrical module.

19. The power generator of claim 18 , wherein the one or more downhole equipment and/or tools comprises one or more of a Measurement-While-Drilling (MWD) sensor, a Pressure-While

Assignees

• Chambers Larry Delynn
• Halliburton Energy Services Inc

Inventors

• Chambers Larry Delynn

Classifications

• H02K7/1807

  Rotary generators (H02K7/006 takes precedence) · CPC title

• H02K21/023 Primary

  by varying the amount of superposition, i.e. the overlap, of field and armature · CPC title

• E21B41/0085 Primary

  Adaptations of electric power generating means for use in boreholes · CPC title

• H02P9/14

  by variation of field (H02P9/08, H02P9/10 take precedence) · CPC title