Mud motor bearing assembly for use with a drilling system

Patent metadata

Field	Value
Publication number	US-11655678-B2
Application number	US-202117305567-A
Country	US
Kind code	B2
Filing date	Jul 9, 2021
Priority date	Jul 9, 2021
Publication date	May 23, 2023
Grant date	May 23, 2023

Abstract

A drilling system for drilling a borehole. The drilling system may include a drill string, a drill bit coupled to the drill string, a mud motor coupled to the drill string uphole of the drill bit and operable to rotate the drill bit via a driveshaft, a bearing assembly coupled to a downhole end of the mud motor and operable to support the driveshaft, and a rotary steerable system (“RSS”) operable to push the drill bit in a desired direction via pads extended using drilling fluid flowing through the driveshaft and to the RSS. The bearing assembly may include bearings positioned circumferentially around a bore of the bearing assembly, a fluid flowpath through the bearings to allow drilling fluid to pass through the bearings, and a choke assembly positioned in the fluid flowpath and operable to restrict a flow of the drilling fluid through the fluid flowpath.

First claim

What is claimed is:

1. A drilling system for drilling a borehole using a drilling fluid, the drilling system comprising:
a drill string;
a mud motor coupled to the drill string and comprising a driveshaft comprising a bore through which the drilling fluid is flowable;
a bearing assembly coupled to a downhole end of the mud motor and operable to support the driveshaft, the bearing assembly comprising:
bearings positioned circumferentially around a bore of the bearing assembly;
a fluid flowpath through the bearings and in fluid communication with the bore of the driveshaft to allow drilling fluid to divert from the bore and pass through the bearings; and
a choke assembly positioned in the fluid flowpath and operable to restrict a flow of the drilling fluid out of the fluid flowpath;

a rotary steerable system (“RSS”) operable to extend pads using drilling fluid not diverted through the fluid flowpath and flowing through the driveshaft and to the RSS; and
a drill bit rotatable by the driveshaft and steerable in a desired direction by the RSS.

2. The drilling system of claim 1 , wherein the choke assembly comprises:
a choke axially movable within the fluid flowpath to contact a seat and restrict fluid flow through the fluid flowpath; and
a biasing mechanism positioned within the fluid flowpath to bias the choke into contact with the seat.

3. The drilling system of claim 2 , wherein the choke assembly further comprises a key coupled to the choke and positioned in a slot formed in an inner housing surrounding the driveshaft to prevent relative rotational movement between the inner housing and the choke and allow relative axial movement between the inner housing and the choke.

4. The drilling system of claim 1 , wherein the bearings comprise a radial bearing assembly shaped to restrict flow of the drilling fluid out the fluid flowpath.

5. The drilling system of claim 1 , wherein the choke assembly comprises a tortuous flowpath to restrict flow of the drilling fluid out the fluid flowpath.

6. The drilling system of claim 5 , wherein an outer labyrinth choke portion and an inner labyrinth choke portion are positioned within the fluid flowpath to form the tortuous flowpath.

7. The drilling system of claim 1 , wherein the fluid flowpath exits the bearing assembly to an annulus surrounding the bearing assembly.

8. The drilling system of claim 1 , wherein the choke assembly allows a range between approximately 1% and approximately 7% of the drilling fluid flowing through the drill string to be diverted into the fluid flowpath.

9. The drilling system of claim 1 , wherein the choke assembly is operable to restrict flow of the drilling fluid such that a pressure of the drilling fluid flowing through the driveshaft is sufficient to extend the pads of the RSS.

10. A method of drilling a borehole, the method comprising:
pumping drilling fluid down a drill string within the borehole to a mud motor, a bearing assembly, a RSS, and a drill bit;
rotating the drill bit via a driveshaft driven by the mud motor powered by the drilling fluid;
diverting a portion of the drilling fluid from the driveshaft and through bearings of the bearing assembly;
restricting a flow of the drilling fluid out of the bearings via a choke assembly;
extending pads of the RSS using the drilling fluid passing through the driveshaft and not diverted through the bearings to push the drill bit in a desired direction.

11. The method of claim 10 , wherein restricting the flow of the drilling fluid out of the bearings via the choke assembly comprises biasing a choke of the choke assembly positioned within a fluid flowpath through the bearings against a seat of the choke assembly positioned within the fluid flowpath.

12. The method of claim 11 further comprising preventing relative rotational movement between the choke and an inner housing of the choke assembly.

13. The method of claim 10 , wherein restricting the flow of the drilling fluid out of the bearings via the choke assembly comprises restricting the flow of the drilling fluid via a tortuous flowpath formed by the choke assembly.

14. The method of claim 10 , further comprising flowing the portion of the drilling fluid from the bearings to an annulus surrounding the bearing assembly.

15. The method of claim 10 , wherein restricting the flow of the drilling fluid out the bearings via the choke assembly comprises restricting the flow of the drilling fluid via the choke assembly such that a pressure of the drilling fluid flowing through the driveshaft is sufficient to extend the pads of the RSS.

16. A bearing assembly for rotatably supporting a driveshaft rotated by a downhole motor rotated via drilling fluid, the bearing assembly comprising:
bearings positioned circumferentially around a bore of the bearing assembly to rotatably support the driveshaft extending from the downhole motor;
a fluid flowpath through the bearings and in fluid communication with a bore of the driveshaft to allow drilling fluid to divert from the bore and pass through the bearings; and
a choke assembly positioned in the fluid flowpath and operable to restrict a flow of the drilling fluid out of the fluid flowpath and maintain a minimum pressure within the bore of the driveshaft.

17. The bearing assembly of claim 16 , wherein the choke assembly comprises:
a choke axially movable within the fluid flowpath to contact a seat and restrict fluid flow through the fluid flowpath; and
a biasing mechanism positioned within the fluid flowpath to bias the choke into contact with the seat.

18. The bearing assembly of claim 17 , wherein the choke assembly further comprises a key coupled to the choke and positioned in a slot formed in an inner housing surrounding the driveshaft to prevent relative rotational movement between the inner housing and the choke and allow relative axial movement between the inner housing and the choke.

19. The bearing assembly of claim 16 , wherein the choke assembly comprises a tortuous flowpath to restrict flow of the drilling fluid out of the fluid flowpath.

20. The bearing assembly of claim 16 , wherein the fluid flowpath exits the bearing assembly to an annulus surrounding the bearing assembly.

Assignees

• Halliburton Energy Services Inc

Inventors

• Munguia Joseph Robert
• Uddin Hasib
• Hardin John

Classifications

• E21B4/003 Primary

  Bearing, sealing, lubricating details (for roller bits E21B10/22) · CPC title

• E21B4/02 Primary

  Fluid rotary type drives · CPC title

• E21B7/068

  drilled by a down-hole drilling motor (down-hole drives per se E21B4/00, E21B7/067 takes precedence) · CPC title