Automated drilling methods and systems using real-time analysis of drill string dynamics

Patent metadata

Field	Value
Publication number	US-12060754-B2
Application number	US-202117450916-A
Country	US
Kind code	B2
Filing date	Oct 14, 2021
Priority date	Feb 22, 2017
Publication date	Aug 13, 2024
Grant date	Aug 13, 2024

Abstract

Methods and apparatus for identifying downhole dynamics in a drilling system are provided. Acceleration-detecting sensors are mounted at multiple locations near to a drill bit, such as at a drill collar. The sensors may be spaced 90° apart along a circumference of the drill collar. The sensors detect acceleration measurements in a plane orthogonal to the drill string's axis of rotation, with respect to a first reference frame that moves with the drill string. The acceleration measurements are received by a processor and processed to determine rotational and revolution positions of the drill string within the wellbore with respect to a static reference frame. Whirl dynamics may, in particular, be determined based on the results in real time.

First claim

What is claimed is:

1. A method for real-time identification of downhole dynamics of a drill string in a drilling system, the method comprising:
obtaining a first acceleration measurement from a first sensor, the first acceleration measurement corresponding to a first sensor location in a first two-dimensional reference frame, the first two-dimensional reference frame coincident with a plane orthogonal to a rotational axis of the drilling system and based on a position of the drilling system in the plane, the first acceleration measurement comprising a first radial acceleration measurement a RA along a first measurement axis parallel to a first radius R A and a first tangential acceleration measurement a θA along a second measurement axis orthogonal to the first measurement axis;
receiving, by a processor, the first acceleration measurement from the first sensor;
obtaining a second acceleration measurement from a second sensor, the second acceleration measurement corresponding to a second sensor location in the first two-dimensional reference frame, the second sensor location spaced apart from the rotational axis by a second radius R B and spaced apart from the first sensor location in the plane, a second radial acceleration measurement a RB along a third measurement axis parallel to the second measurement axis and a second tangential acceleration measurement a θB along a fourth measurement axis parallel to the first measurement axis;
receiving, by the processor, the second acceleration measurement from the second sensor;
identifying, by the processor, a downhole dynamic of the drill string of the drilling system based on the first and second acceleration measurements; and
varying one or more of hook load, surface RPM, mud pressure, top drive quill position and top drive oscillation amount in response to identifying the downhole dynamic of the drill string of the drilling system.

2. The method according to claim 1 comprising:
converting, by the processor, the first sensor location to a corresponding converted location of the drilling system in a second two-dimensional reference frame based on the first and second acceleration measurements, the second two-dimensional reference frame coincident with the plane and invariant with the position of the drilling system in the plane; and
determining, by the processor, a revolution position of the drilling system in the second two-dimensional reference frame based on the converted location, the revolution position describing revolution of the drilling system in the plane about a revolution axis;
wherein identifying the downhole dynamic of the drill string comprises identifying, by the processor, a whirl dynamic based on the revolution position.

3. The method according to claim 2 further comprising determining, by the processor, a rotational position of the drilling system in the first two-dimensional reference frame based on the first and second acceleration measurements, the rotational position describing rotation of the drilling system in the plane about the rotational axis.

4. The method according to claim 3 comprising transmitting, by the processor, at least one of the first and second acceleration measurements, the rotational position, and the revolution position to an at-surface processor.

5. The method according to claim 4 comprising presenting, by the at-surface processor, the whirl dynamic to a user based on the revolution position.

6. The method according to claim 3 comprising controlling an at-surface drilling pipe position, based on one or more of the rotational position and revolution position, while the drilling system is conducting a sliding drilling operation, by oscillating the drilling pipe at surface back and forward in equal incremental angles clockwise and counter-clockwise until the processor determines a non-zero rotational position or non-zero revolution position.

7. The method according to claim 1 comprising performing, by the processor, calculations for one or more of an angular rotational position θ, angular rotational velocity dθ/dt, angular rotational acceleration d 2 θ/dt 2 , revolution radius r G , radial revolution velocity dr G /dt, radial revolution acceleration d 2 r G /dt 2 , revolution angle ϕ, angular revolution velocity dϕ/dt, and angular revolution acceleration d 2 ϕ/dt 2 based on the first and second acceleration measurements.

8. The method according to claim 7 comprising transmitting a notification signal to the surface when a difference between maximum and average values of one of the angular rotational position θ, angular rotational velocity dθ/dt, angular rotational acceleration d 2 θ/dt 2 , revolution radius r G , radial revolution velocity dr G /dt, radial revolution acceleration d 2 r G /dt 2 , revolution angle ϕ, angular revolution velocity dϕ/dt, and angular revolution acceleration d 2 ϕ/dt 2 exceeds a predetermined threshold over a predetermined period.

9. The method according to claim 7 comprising determining, by the processor, an at surface maximum revolution radius r G based on one or more of the point where dr G /dt=dr 2 G /dt 2 =0 and where there is a change in sign of dr G /dt or dr 2 G /dt 2 .

10. The method according to claim 1 comprising transmitting, by the processor, the first and second acceleration measurements to the surface at periodic intervals and calculating at surface, by an at-surface processor, one or more of an angular rotational position θ, angular rotational velocity dθ/dt, angular rotational acceleration d 2 θ/dt 2 , revolution radius r G , radial revolution velocity dr G /dt, radial revolution acceleration d 2 r G /dt 2 , revolution angle ϕ, angular revolution velocity dϕ/dt, and angular revolution acceleration d 2 ϕ/dt 2 based on the first and second acceleration measurements.

11. The method according to claim 10 wherein a frequency at which the first and second acceleration measurements are transmitted to the surface is configurable to accommodate a telemetry rate.

12. The method according to claim 1 comprising determining, by the processor, one or more drilling parameters based on one or more of an angular rotational position θ, angular rotational velocity dθ/dt, angular rotational acceleration d 2 θ/dt 2 , revolution radius r G , radial revolution velocity dr G /dt, radial revolution acceleration d 2 r G /dt 2 , revolution angle ϕ, angular revolution velocity dϕ/dt, and angular revolution acceleration d 2 ϕ/dt 2 .

13. The method according to claim 12 wherein the drilling parameters comprise one or more of:
torque on bit T o ;
drilling efficiency; and
weight on bit (WOB).

14. The method according to claim 13 comprising determining, by the processor, an indication of the drilling efficiency based on an output torque and a surface torque, wherein the output torque comprises a desired portion of torque applied to the drill bit or string to cut through the formation, and the surface torque comprises the torque applied to drive the drill bit or string at the surface.

15. The method according to claim 14 comprising determining, by the processor, modified values for one or more of revolutions per minute (RPM), WOB, top drive quill position (TF) and mud flow rate for the drilling system in order to reduce the whirl dynamic to a zero or near-zero value based on one or more of:
one or more of the angular rotational position θ, angular rotational velocity dθ/dt, angular rotational acceleration d 2 θ/dt 2 , revolution radius r G , radial revolution velocity dr G /dt, radial revolution acceleration d 2 r G /dt 2 , revolution angle ϕ, angular revolution velocity dϕ/dt, and angular revol

Assignees

• Evolution Engineering Inc

Inventors

• Kazemi Miraki Mojtaba
• Logan Aaron W

Classifications

• E21B47/007

  Measuring stresses in a pipe string or casing (for locating blocked portions of pipes E21B47/09) · CPC title

• G01P15/18

  in two or more dimensions · CPC title

• E21B47/024

  of devices in the borehole (determining slope or direction of the borehole E21B47/022) · CPC title

• E21B44/04

  in response to the torque of the drive {; Measuring drilling torque (E21B44/06 takes precedence; measuring stresses in a well bore pipe E21B47/007)} · CPC title

• E21B7/04

  Directional drilling · CPC title