Downhole power generation using a mud operated pulser

Patent metadata

Field	Value
Publication number	US-9528349-B2
Application number	US-201314374622-A
Country	US
Kind code	B2
Filing date	Sep 25, 2013
Priority date	Sep 25, 2013
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

The present disclosure relates to generating electricity downhole using a mud-operated pulser. A disclosed example embodiment of a mud pulser system includes a piston assembly movably disposed within a housing, comprising a power piston, and configured to move in response to a pressure from a fluid flow, a control valve having an open state, in which the power piston receives the fluid flow, and a closed state, in which the power piston does not receive the fluid flow, a magnet disposed on the housing or the piston assembly, and a coil disposed on the housing or the piston assembly, wherein the magnet is configured to displace relative to the coil in response to movement of the piston assembly within the housing, such that relative movement of the magnet and the coil generates electrical energy.

First claim

What is claimed is:

1. A mud pulser system, comprising:
a piston assembly movably disposed within a housing and including a power piston, the piston assembly being configured to move in response to pressure from a fluid flow;
a control valve having an open state, in which the power piston receives the fluid flow, and a closed state, in which fluid flow is prevented from interacting with the power piston;
a magnet disposed on one of the housing and the piston assembly; and
a coil disposed on the other of the housing and the piston assembly, wherein the magnet is configured to displace relative to the coil in response to movement of the piston assembly within the housing, such that relative movement of the magnet and the coil generates electrical energy.

2. The mud pulser system of claim 1 , wherein the piston assembly further comprises a poppet and the housing comprises a flow line orifice disposed upstream of the power piston, the piston assembly being movably disposed within the flow line orifice, and wherein the magnet is disposed at the poppet and the coil is disposed at the flow line orifice of the housing.

3. The mud pulser system of claim 2 , wherein the piston assembly further comprises a shaft disposed axially between the poppet and the power piston and the housing further comprises a flow shroud, wherein the shaft is movably disposed within the flow shroud, and wherein the magnet is disposed at the shaft of the piston assembly and the coil is disposed at the flow shroud of the housing.

4. The mud pulser system of claim 1 , wherein the magnet is disposed at the power piston of the piston assembly.

5. The mud pulser system of claim 1 , wherein, when the control valve is in the open state, a side of the power piston of the piston assembly is exposed to the pressure from the fluid flow.

6. The mud pulser system of claim 1 , wherein the piston assembly is configured to move in a first axial direction when the control valve is in the open state and in a second axial direction, opposite the first axial direction, when the control valve is in the closed state.

7. A method of generating electrical power downhole with a mud pulser system, comprising:
receiving, by the mud pulser system, a first flow from an upstream region through a flow line orifice and past a poppet of a piston assembly to a downstream region;
receiving a second flow from the upstream region to a control valve;
opening the control valve, such that the piston assembly moves in a first axial direction;
closing the control valve, such that the piston assembly moves in a second axial direction, opposite the first axial direction; and
generating electrical power by axial movement of the piston assembly.

8. The method of claim 7 , wherein generating electrical power comprises moving a magnet and a coil relative to each other to induce a current within the coil.

9. The method of claim 7 , wherein opening the control valve comprises exposing a first side of a power piston to a pressure from the upstream region.

10. The method of claim 7 , wherein the control valve opens when the poppet achieves a first position and wherein the control valve closes when the poppet achieves a second position, axially closer to the flow line orifice than the first position.

11. The method of claim 7 , wherein closing the control valve comprises isolating a first side of a power piston of the piston assembly from a pressure from the upstream region.

12. The method of claim 7 , wherein, when the control valve is open, a pressure differential across a power piston of the piston assembly is equal to the pressure differential across the flow line orifice.

13. The method of claim 7 , further comprising storing the electrical power.

14. The method of claim 7 , further comprising providing the electrical power to a tool of a bottom hole assembly.

15. A mud pulser system, comprising:
a housing having a flow line orifice with a cross-sectional area less than a cross-sectional area of an upstream region disposed upstream of the flow line orifice and a downstream region disposed downstream of the flow line orifice;
a piston assembly configured to move axially within the housing and comprising (i) a shaft having a conduit fluidly connecting the upstream region with a control chamber; (ii) a poppet attached to the shaft, at least partially disposed in the downstream region, and defining a flow line gap between the poppet and the flow line orifice; and (iii) a power piston separating a first piston chamber, in fluid communication with the downstream region, from a second piston chamber;
a control valve configured to permit fluid communication between the second piston chamber and the control chamber in an open state and prevent fluid communication between the second piston chamber and the control chamber in a closed state; and
a power generation unit comprising a magnet and a coil configured to achieve relative axial motion in response to axial motion of the piston assembly.

16. The mud pulser system of claim 15 , wherein a pressure at the upstream region is greater than a pressure at the downstream region.

17. The mud pulser system of claim 15 , wherein the poppet is configured to move axially towards the flow line orifice when the control valve is opened.

18. The mud pulser system of claim 15 , wherein the piston assembly is configured to move axially away from the flow line orifice when the control valve is closed.

19. The mud pulser system of claim 15 , wherein the magnet is disposed at a poppet of the piston assembly and the coil is disposed at a flow line orifice of the housing.

Assignees

• Halliburton Energy Services Inc

Inventors

• Zimmerman Mark

Classifications

• E21B34/06

  in wells · CPC title

• E21B41/0085 Primary

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

• E21B47/18

  through the well fluid {, e.g. mud pressure pulse telemetry} · CPC title