Closed loop drilling system

• US 6,233,524 B1
• Filed: 08/03/1999
• Issued: 05/15/2001
• Est. Priority Date: 10/23/1995
• Status: Expired due to Term

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Dubinsky, Valdimir, Leggett, James V. III, Harrell, John W.
• Primary Examiner(s): McElheny, Jr., Donald E.
• Application Number:
  US09/368,044
• Time in Patent Office: 651 Days
• Field of Search: 702/6, 702/9, 175/24, 175/25, 175/27, 175/39, 175/45, 175/48, 175/50, 731/524.6, 731/524.7, 731/524.8
• US Class Current: 702/9
• 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 44/005 Below-ground automatic control systems
• CPC Class Codes: E21B 47/00 Survey of boreholes or wells monitoring pressure or flow of drilling fluid E21B21/08
• CPC Class Codes: E21B 47/18 through the well fluid , e.g. mud pressure pulse telemetry
• CPC Class Codes: E21B 7/068 drilled by a down-hole drilling motor down-hole drives per se E21B4/00, E21B7/067 takes precedence

Abstract

The present invention provides a closed-loop drilling system for drilling oilfield boreholes. The system includes a drilling assembly with a drill bit, a plurality of sensors for providing signals relating to parameters relating to the drilling assembly, borehole, and formations around the drilling assembly. Processors in the drilling system process sensors signal and compute drilling parameters based on models and programmed instructions provided to the drilling system that will yield further drilling at enhanced drilling rates and with extended drilling assembly life. The drilling system then automatically adjusts the drilling parameters for continued drilling. The system continually or periodically repeats this process during the drilling operations. The drilling system also provides severity of certain dysfunctions to the operator and a means for simulating the drilling assembly behavior prior to effecting changes in the drilling parameters.

Claims

1. An automated drilling system for drilling wellbores, comprising:

(a) a drilling assembly comprising a drill bit at an end thereof;

(b) a plurality of sensors for providing measurements relating to one or more conditions of the drilling assembly (drilling assembly parameters);

(c) a force application device for applying force on the drill bit during drilling of the welibore;

(d) a rotator for rotating the drill bit;

(e) a source of drilling fluid at the surface for supplying drilling fluid under pressure to the drilling assembly; and

(f) a processor having an associated model, said processor cooperating with said model and utilizing the measurements relating to the one or more conditions of the drilling assembly to compute a combination of drilling parameters that when used for further drilling of the wellbore will yield at least one of (i) enhanced drilling rate and (ii) extended drilling assembly life, wherein said processor further causing the drilling system to alter the drilling parameters to the computed values for further drilling of the wellbore.

2. The automated drilling system of claim 1 wherein the drilling parameters include at least one parameter selected from a group consisting of (i) force on the drill bit (weight on bit), (ii) rotational speed of the drill bit, and (iii) flow rate of the supply of the drilling fluid.

3. The automated drilling system of claim 1 wherein the drilling parameters include a parameter selected from a group consisting of (i) differential pressure across a drilling motor in the drilling assembly for rotating the drill bit, (ii) differential pressure between the drilling motor and fluid in an annulus between the drilling motor and the wellbore, and (iii) temperature of an elastomeric member in the drilling motor.

4. The automated drilling system of claim 1 wherein the processor further includes a computer at the surface and a second model associated with the computer.

5. The automated drilling system of claim 1 further comprising one or more formation evaluation sensors for determining one or more formation parameters and wherein the processor further determines the drilling parameters as a function of the one or more formation parameters.

6. The automated drilling system of claim 5 wherein the processor computes the drilling parameters and formation parameters at least in part downhole and transmits such computed parameters to a computer at the surface which controls the drilling parameters.

7. The automated drilling system of claim 1 wherein the processor includes a downhole processor and computer at the surface that receives the drilling parameters from the downhole processor and computes the values of the drilling parameters utilizing a model associated with said computer.

8. The automated drilling system of claim 1, wherein the force application device comprises a thruster downhole in the drilling assembly and wherein the processor controls the thruster downhole to apply a computed value of the force on the drill bit.

9. The automated drilling system of claim 8 wherein the thruster includes a wellbore engagement device for selectively engaging a sidewall of the wellbore on application of thrust force by the thruster, with the processor signaling a rig at the surface to supply tubing as necessary for continued drilling operations.

10. The automated drilling system of claim 1, wherein the force application device comprises a rotary rig at the surface, with the rotary rig further supplying tubing as necessary for continued drilling operations.

11. The automated drilling system of claim 1, wherein the force application device comprises a coiled tubing rig at the surface, with the coiled-tubing rig further supplying tubing as necessary for continued drilling operations.

12. The automated drilling system of claim 1, wherein the rotator is a rotary rig at the surface.

13. The automated drilling system of claim 10, wherein the rotator is one of (i) a drilling motor in the drilling assembly driven by the fluid under pressure supplied from a source at the surface, (ii) a rotary rig, or (iii) a combination of a drilling motor and rotary rig.

14. The automated drilling system of claim 10 wherein the drilling assembly further comprises a direction control device for steering the drilling assembly during drilling of the wellbore.

15. The automated drilling system of claim 14 wherein the direction control device includes at least one adjustable member extending outwardly from the drilling assembly to apply force on the wellbore inside to alter the drilling direction.

16. The automated drilling system of claim 15 wherein the sensors include at least one position sensor providing measurements for the location of the drill bit relative to a known position.

17. The automated system of claim 16 wherein the processor determines the location of the drill bit from the position sensor measurements and controls the adjustable member to maintain the drilling direction along a predetermined path.

18. The automated system of claim 1 wherein the drilling assembly parameters include at least one parameter selected from a group consisting of bit bounce, shock, lateral vibration, axial vibration, radial force on the drilling assembly, stick-slip, whirl, bending moment, drill bit wear, bit bounce, whirl, and axial force on the drilling assembly.

19. The automated drilling system of claim 1 wherein the sensors are selected from a group consisting of a pressure sensor, accelerometer, magnetometer, gyroscopes, temperature sensor, force on bit sensors, and drill bit wear sensor.

20. The automated drilling system of claim 1 further comprising a transmitter downhole communicating between the drilling assembly and a surface computer via media selected from a group consisting of electromagnetic, tubing acoustic, fluid acoustic, mud pulse, fiber optics, and electric conductor.

21. The automated drilling system of claim 5 wherein the formation evaluation sensors include at least one sensor selected from resistivity sensor, acoustic sensor for determining the porosity of the formation, acoustic sensor for determining bed boundary conditions, gamma ray sensor, and nuclear sensor for determining the density of the formation.

22. An automated method for drilling a wellbore with a drilling system having drilling assembly conveyed in the wellbore by a tubing, wherein the drilling assembly includes a drill bit at an end thereof, a plurality of drilling assembly parameter sensors that provide measurements for determining one or more drilling assembly parameters, a model associated with the drilling assembly for manipulating data downhole, and a processor for processing signals downhole, and wherein the drilling system further includes a force application device for applying weight on bit, a rotator for rotating the drill bit at a desired rotational speed, and a source of drilling fluid at the surface for supplying drilling fluid under pressure at a selected flow rate to the drilling assembly, said method comprising:

(a) conveying the drilling assembly with the tubing into the wellbore and drilling said wellbore with the drilling assembly;

(b) computing downhole from the measurements of the drilling assembly parameter sensors the one or more drilling assembly parameters with the processor utilizing the model during drilling of the wellbore;

(c) utilizing the one or more computed drilling assembly parameters to determine the values of the one or more drilling parameters which if utilized for further drilling will provide at least one of (i) drilling of the wellbore at an enhanced rate of penetration and (ii) extended life of the drilling assembly to drill the wellbore; and

(d) continuing further drilling of the wellbore at the determined values of the one or more drilling parameters to drill the wellbore.

23. The automated method of drilling the wellbore as specified in claim 22 further comprising repeating steps (b)-(d) during the drilling of the wellbore.

24. The automated method of drilling the wellbore as specified in claim 22 wherein determining the values of the drilling parameters further comprises:

(a) transmitting the computed values of the drilling assembly parameters to a surface control unit; and

(b) determining the values of the drilling parameters at the surface with the control unit.

25. The automated method of drilling the wellbore as specified in claim 22 wherein the control unit at the surface automatically controls the rotator, force application device and the flow rate of the drilling fluid for continued drilling of the wellbore to drill the wellbore at the determined values of the drilling parameters, thereby drilling the wellbore with at least one of (i) an enhanced rate of penetration, and (ii) with extended life of the drilling assembly.

26. The automated method of drilling the wellbore as specified in claim 22 further comprising:

(a) providing a plurality of formation evaluation sensors in the drilling assembly for obtaining measurements for determining characteristics of the formation surrounding the drilling assembly;

(b) determining values of at least one characteristic of the formation surrounding the drilling assembly from the measurements of the formation evaluation sensors during the drilling of the wellbore; and

wherein the processor utilizes the computed values of the drilling assembly parameters and the determined values of the characteristics of the formation to determine the values of the drilling parameters.

27. The closed automated method of drilling the wellbore as specified in claim 22 further comprising:

(a) determining at least one drilling direction parameter during the drilling of the wellbore; and

(b) maintaining direction of drilling of the wellbore in response to the determined drilling direction parameter along a prescribed well path.