Borehole fluid-pulse telemetry apparatus and method

Patent metadata

Field	Value
Publication number	US-9334725-B2
Application number	US-201314439455-A
Country	US
Kind code	B2
Filing date	Dec 30, 2013
Priority date	Dec 30, 2013
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

A fluid pulse generator for use in a drill string comprises an elongate obstruction member mounted in a fluid passage for driven pivoting about a pivot axis transverse to the fluid passage, obstruction of the fluid passage by the obstruction member being variable in relation to pivotal position of the obstruction member. Telemetry signals can be transmitted along the drill string by driven pivoting of the obstruction member, to generate data pulses in drilling fluid in the drill string. Pressure-locking of the obstruction member in a maximally obstructive position can be counteracted by provision of a bypass arrangement to allow bypass flow at a leading end of the obstruction member.

First claim

What is claimed is:

1. An apparatus for producing fluid pulse telemetry signals, the apparatus comprising:
a body having a fluid passage therethrough, the body configured for incorporation in a drill string to permit flow of borehole fluid through the fluid passage in a fluid flow direction; and
an elongate obstruction member pivotably mounted in the fluid passage about a pivot axis transverse to the fluid flow direction, such that an extent of obstruction of the fluid passage by the obstruction member varies in relation to pivotal position of the obstruction member.

2. The apparatus of claim 1 , wherein at least a portion of the fluid passage has a noncircular cross-section along which an end of the obstruction member moves when pivoting.

3. The apparatus of claim 2 , wherein the noncircular cross-section is oblong, the fluid passage having a depth dimension greater than a transverse width dimension orthogonal thereto, the pivot axis of the obstruction member being substantially parallel to the width dimension of the fluid passage.

4. The apparatus of claim 3 , wherein the obstruction member substantially spans the fluid passage widthwise, allowing fluid flow substantially exclusively through a pair of end gaps defined between the body and opposite lengthwise end portions of the obstruction member.

5. The apparatus of claim 3 , wherein a length dimension of the obstruction member is greater than the depth dimension of the fluid passage, the obstruction member being pivotable to a maximally obstructive position in which at least one of a pair of lengthwise end portions of the obstruction member bears against the body.

6. The apparatus of claim 5 , wherein the obstruction member and the fluid passage are configured such that only one of the pair of opposite lengthwise end portions engages the body when the obstruction member is disposed in the maximally obstructive position, a bypass clearance being defined between the body and the other one of the pair of lengthwise end portions.

7. The apparatus of claim 1 , further comprising a bias arrangement configured to exert a biasing torque on the obstruction member, to urge the obstruction member to a minimally obstructive position.

8. The apparatus of claim 7 , wherein the bias arrangement is configured to cause biasing of the obstruction member to the minimally obstructive position through hydrodynamic action of borehole fluid on the obstruction member in response to the flow of borehole fluid through the fluid passage.

9. The apparatus of claim 1 , further comprising a drive mechanism operatively coupled to the obstruction member and configured to drive bidirectional movement of the obstruction member about the pivot axis, to produce the fluid pulse telemetry signals.

10. The apparatus of claim 9 , wherein the drive mechanism is configured for controlling variation of a pivot angle through which the obstruction member is displaceable about the pivot axis during driven bidirectional movement, thereby to control variation in pulse amplitude of the fluid pulse telemetry signals.

11. The apparatus of claim 1 , in which the obstruction member is disposable to a maximally obstructive position in which the obstruction member substantially occludes the fluid passage, the apparatus further comprising a bypass arrangement configured to permit, when the obstruction member is in the maximally obstructive position, relief flow from an upstream side of the obstruction member to a downstream side of the obstruction member.

12. The apparatus of claim 11 , wherein the bypass arrangement comprises one or more peripheral grooves in an exterior surface of the obstruction member.

13. The apparatus of claim 11 , wherein the bypass arrangement comprises an internal bypass channel extending longitudinally through the obstruction member.

14. The apparatus of claim 1 , wherein the body has a plurality of fluid passages and a plurality of obstruction members, each obstruction member being mounted in a corresponding one of the plurality of fluid passages.

15. The apparatus of claim 14 , wherein the plurality of obstruction members comprises a pair of obstruction members that are mounted for co-axial pivoting, the pair of obstruction members being located in respective fluid passages which are laterally spaced relative to the fluid flow direction.

16. A method for producing fluid pulse telemetry signals in a drill string, the method comprising:
incorporating in the drill string a signal generator comprising an elongate obstruction member mounted in a fluid passage located in the drill string to convey borehole fluid in a fluid flow direction, the obstruction member being pivotable about a pivot axis transverse to the fluid flow direction; and
generating data pulses in the borehole fluid by driven bidirectional pivoting of the obstruction member, to vary an extent of obstruction of the fluid passage by the obstruction member.

17. The method of claim 16 , wherein the signal generator comprises a plurality of elongate obstruction members pivotally mounted in respective fluid passages, and wherein the generating of the data pulses comprises causing synchronous pivoting of the plurality of obstruction members.

18. The method of claim 17 , wherein the synchronous pivoting comprises independently driven pivotal oscillation of the plurality of obstruction members at different respective amplitudes and/or frequencies.

19. The method of claim 17 , wherein the synchronous pivoting to generate the data pulses comprises:
pivotally oscillating a particular one of the plurality of obstruction members to produce the data pulses; and
controlling fluid velocity at the fluid passage by adjusting a pivotal position of another one of the obstruction members, thereby to control amplitudes of the data pulses.

20. A drill string comprising:
drill pipe configured to extend lengthwise within a borehole and defining a fluid conduit to convey borehole fluid, the fluid conduit including a fluid passage to convey borehole fluid in a fluid flow direction;
an elongate obstruction member pivotably mounted in the fluid passage about a pivot axis transverse to the fluid flow direction; and
a drive mechanism coupled to the obstruction member and configured for driving bidirectional pivoting of the obstruction member, to vary an extent of obstruction of the fluid passage by the obstruction member and thereby to produce data-carrying fluid pressure variations in the borehole fluid.

Assignees

• Halliburton Energy Services Inc
• Halliburton Energy Services Inc

Inventors

• Sitka Mark Anthony

Classifications

• E21B47/18 Primary

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

• E21B47/24 Primary

  by positive mud pulses using a flow restricting valve within the drill pipe · CPC title