Methods and systems for drilling

• US 10,415,365 B2
• Filed: 05/24/2017
• Issued: 09/17/2019
• Est. Priority Date: 04/12/2010
• Status: Active Grant

• Current Assignee: Shell USA Incorporated (Shell Plc)
• Original Assignee: Shell Oil Company (Shell Plc)
• Inventors: Edbury, David Alston, Guerrero, Jose Victor, Macdonald, Duncan Charles, Rogers, James Bryon, Sitton, Donald Ray, Norman, Jason B.
• Primary Examiner(s): Harcourt, Brad
• Application Number:
  US15/604,157
• Publication Number:
  US 20170260822A1
• Time in Patent Office: 846 Days
• CPC Class Codes: E21B 21/01 Arrangements for handling drilling fluids or cuttings outside the borehole, e.g. mud boxes
• CPC Class Codes: E21B 21/08 Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure valve arrangements therefor E21B21/10
• CPC Class Codes: E21B 37/00 Methods or apparatus for cleaning boreholes or wells E21B21/00 takes precedence
• CPC Class Codes: E21B 44/00 Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions
• CPC Class Codes: E21B 44/02 Automatic control of the tool feed E21B44/005, E21B44/10 take precedence
• CPC Class Codes: E21B 44/06 in response to the flow or pressure of the motive fluid of the drive
• CPC Class Codes: E21B 47/00 Survey of boreholes or wells monitoring pressure or flow of drilling fluid E21B21/08
• CPC Class Codes: E21B 47/003 Determining well or borehole volumes
• CPC Class Codes: E21B 49/005 Testing the nature of borehole walls or the formation by using drilling mud or cutting data
• CPC Class Codes: E21B 7/06 Deflecting the direction of boreholes

Abstract

A method of controlling a direction of drilling of the drill string used to form an opening in a subsurface formation, comprises varying a speed of the drill string during rotational drilling such that the drill string is at a first speed during a first portion of the rotational cycle and at a second speed during a second portion of the rotational cycle wherein the first speed is higher than the second speed, and wherein operating at the second speed in the second portion of the rotational cycle causes the drill string to change the direction of drilling.

Claims

1. A method of controlling a direction of drilling of a drill string used to form an opening in a subsurface formation, comprising:

varying a speed of the drill string during rotational drilling such that the drill string is operated at a first speed during a first portion of a rotational cycle and operated at a second speed during a second portion of the rotational cycle wherein the first speed is higher than the second speed, wherein operating at the second speed in the second portion of the rotational cycle causes the drill string to change the direction of drilling in a direction of the second portion, wherein the second portion of the rotational cycle is a portion of the rotational cycle in which a toolface of the drilling string faces a desired direction for the drill string to proceed, and wherein a rotational position of the toolface is correlated with a rotational position of a top drive rotating a spindle at a surface of the formation and

dynamically computing an estimated rotational position of the toolface using a measured actual rotational position of the top drive, in combination with recent data on the toolface received from a measurement while drilling tool.

2. The method of claim 1 wherein varying the speed of the drill string comprises making a course correction.

3. The method of claim 2 wherein the course correction is made following a straight ahead lateral.

4. The method of claim 1 wherein varying the speed of the drill string comprises automatically determining a rotation speed for at least one portion of the rotational cycle.

5. The method of claim 1 wherein varying the speed of the drill string comprises automatically determining a sweep angle for at least one portion of the rotational cycle.

6. The method of claim 1, further comprising:

establishing a desired turn rate for the drill string; and

automatically determining, based on the desired turn rate, at least one of a sweep angle for at least one portion of the rotational cycle or a rotation speed for at least one portion of the rotational cycle.

7. The method of claim 1 wherein the first portion of the rotational cycle is about 90 degrees and the second portion of the rotational cycle is about 270 degrees.

8. The method of claim 1 wherein the second portion of the rotational cycle is between 15% and about 30% of the rotational cycle of the drill string.

9. The method of claim 1 wherein the second speed is at most about ⅕

of the first speed.

10. The method of claim 1 wherein the first speed is at most about 10 rpm.

11. The method of claim 1, further comprising varying a rotation speed of the drill string for at least a portion of one rotational cycle.

12. A tangible, computer readable memory medium comprising program instructions stored thereon wherein the program instructions are computer-executable to implement the method of claim 1.

13. The method of claim 1, wherein the dynamically computed estimated rotational position of the toolface is a continuous indicator of the toolface and fills time gaps between intermittent downhole updates from the measurement while drilling tool.

14. The method of claim 1, wherein dynamically computing the estimated rotational position of the toolface is performed with the drill string at a specified RPM set point and a target motor differential pressure, while other drilling set points and targets are maintained.

15. The method of claim 1, wherein a lag time between downhole sampling of the toolface and data decoding at the surface is accounted for by programming the lag time into a programmable logic controller or by measured and accounting for an RPM based offset.