Hybrid rotary steerable system and method

Patent metadata

Field	Value
Publication number	US-11028646-B2
Application number	US-201816488976-A
Country	US
Kind code	B2
Filing date	Feb 23, 2018
Priority date	Feb 28, 2017
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

A rotary steerable drilling system includes a collar, a drill bit, and a bit shaft connecting the drill bit to the collar. The bit shaft is coupled to the collar through a joint capable of transmitting a torque from the collar to the bit shaft and is swingable with respect to the collar around the joint. The system, further includes first eccentric wheel and second eccentric wheel coupled to the bit shaft and rotatable to swing the bit shaft with respect to the collar around the joint to change a drilling direction, a controller for controlling the first eccentric wheel and second eccentric wheel to harmoniously rotate such that the swing of the bit shaft substantially compensates rotation of the bit shaft, and an active stabilizer mounted on the bit shaft and capable of pushing the bit shaft to deviate to cause a lateral displacement and a tilt angle of the drill bit.

First claim

The invention claimed is:

1. A rotary steerable drilling system for drilling a borehole,
comprising:
a collar;
a drill bit;
a bit shaft connecting the drill bit to the collar, the bit shaft coupled to the collar through a joint capable of transmitting a torque from the collar to the bit shaft, and swingable with respect to the collar around the joint;
a first eccentric wheel and a second eccentric wheel coupled to the bit shaft, and rotatable to swing the bit shaft with respect to the collar around the joint causing a tilt angle of the drill bit;
a controller for controlling the first and second eccentric wheels to rotate such that the swing of the bit shaft with respect to the collar substantially compensates rotation of the collar; and
a stabilizer fixedly mounted on the bit shaft and rotatable with the bit shaft, the stabilizer being capable of contacting an inner surface of the borehole to push the collar via the joint to generate a lateral displacement, wherein the lateral displacement and the tilt angle of the drill bit changes a drilling direction.

2. The system according to claim 1 , wherein the bit shaft has opposite first and second axial ends, the joint is between the first and second axial ends, and the drill bit is coupled to the first axial end of the bit shaft and the first and second eccentric wheels are coupled to the second axial end of the bit shaft.

3. The system according to claim 1 , wherein the bit shaft comprises an upper section within the collar and a lower section outside the collar, and the stabilizer is fixed on the upper section of the the bit shaft.

4. The system according to claim 3 , wherein the stabilizer has an outer surface for contacting an inner surface of the borehole, and the stabilizer comprises ribs extending between the outer surface thereof and an outer surface of the bit shaft, the ribs passing through the collar.

5. The system according to claim 1 , wherein the joint is located between the drill bit and the stabilizer along an axial direction of the bit shaft.

6. The system according to claim 1 , wherein the joint is a universal joint.

7. The system according to claim 6 , wherein the universal joint includes a plurality of balls, each of the balls contained in a space defined between the collar and the bit shaft, wherein the space is surplus for the ball along an axial direction of the collar to allow the bit shaft to swing with respect to the collar around the joint.

8. The system according to claim 1 , wherein the first eccentric wheel is coupled between the collar and the second eccentric wheel and the second eccentric wheel is coupled between the first eccentric wheel and the bit shaft.

9. The system according to claim 1 , further comprising a first motor and a second motor for driving the first eccentric wheel and the second eccentric wheel, respectively.

10. The system according to claim 9 , wherein the first and second motors drive the first and second eccentric wheels through a gear drive train respectively, the gear drive train comprising at least one gear fixed with the first eccentric wheel or the second eccentric wheel.

11. The system according to claim 9 , further comprising a measurement module, the measurement module measuring one of a rotation parameter and a gesture parameter of one of the collar and the bit shaft.

12. The system according to claim 11 , wherein the controller controls at least one of the first motor and the second motor based on the at least one of the rotation parameter and the gesture parameter measured by the measurement module.

13. The system according to claim 1 , wherein a distance between a rotary axis of the first eccentric wheel and a rotary axis of the second eccentric wheel is substantially equal to a distance between the rotary axis of the second eccentric wheel and a center of an upper end of the bit shaft.

14. The system according to claim 1 , wherein the controller controls the first and second eccentric wheel to swing the bit shaft to keep the drill bit pointing to a specific direction with respect to a formation being drilled.

15. The system according to claim 1 , wherein the controller controls the first eccentric wheel and the second eccentric wheel to rotate such that the swing of the bit shaft with respect to the collar substantially compensates rotation of the stabilizer.

16. A rotary steerable drilling method, comprising:
drilling a borehole with a drill bit coupled to a collar via a bit shaft, while rotating the collar, the bit shaft and the drill bit;
rotating a first eccentric wheel and a second eccentric wheel coupled with the bit shaft, to swing the bit shaft with respect to the collar around a joint adapted to connect the bit shaft to the collar and transmit a torque from the collar to the bit shaft, the swing of the bit shaft causing a tilt angle of the drill bit;
controlling the first and second eccentric wheels to harmoniously rotate such that the swing of the bit shaft substantially compensates the rotation of the collar; and
pushing the collar with a stabilizer fixedly mounted on the bit shaft and rotating with the bit shaft the stabilizer being capable of contacting an inner surface of the borehole such that the collar generates a lateral displacement, wherein the lateral displacement and the tilt angle of the drill bit, changes a drilling direction.

17. The method according to claim 16 , wherein the collar is rotated with respect to the borehole at a first angular speed Ω, the first eccentric wheel is rotated with respect to the collar at a second angular speed ω, and the second eccentric wheel is rotated to keep the second eccentric wheel at an expected angle with respect to the first eccentric wheel while changing the drilling direction, wherein the first angular speed Ω and the second angular speed co are substantially equal and opposite in direction.

Assignees

• Gen Electric

Inventors

• Ren Zhiguo
• Fu Xu
• Brazil Stewart Blake
• Wang Chengbao

Classifications

• E21B7/04 Primary

  Directional drilling · CPC title

• E21B7/061

  the tool shaft advancing relative to a guide, e.g. a curved tube or a whipstock · CPC title

• E21B17/05

  Swivel joints · CPC title

• E21B7/067 Primary

  with means for locking sections of a pipe or of a guide for a shaft in angular relation, e.g. adjustable bent sub · CPC title

• E21B7/06

  Deflecting the direction of boreholes · CPC title