Drilling system utilizing downhole dysfunctions for determining corrective actions and simulating drilling conditions

• US 6,021,377 A
• Filed: 10/23/1996
• Issued: 02/01/2000
• 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, Vladimir, Leggett, James V. III
• Primary Examiner(s): McElheny, Jr., Donald E.
• Application Number:
  US08/735,862
• Time in Patent Office: 1,196 Days
• Field of Search: 702/9, 702/16, 175/24, 175/25, 175/27, 175/39, 175/45, 175/48, 175/50, 367/81, 367/92, 367/83, 73/152, 73/46, 73/152.47, 73/152.48, 340/853.3, 340/853.4, 340/853.5, 340/853.6
• 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 system for drilling boreholes. The system includes a drill string having a drill bit, a plurality of sensors for providing signals relating to the drill string and formation parameters, a downhole device which processes various downhole sensors signals and computes dysfunctions relating to the drilling operations and transmits such dysfunctions to a surface control unit. The surface control unit determines the relative severity of such dysfunctions and the corrective action required to alleviate such dysfunctions based on programmed instruction and then displays the nature and extent of such dysfunctions and the required corrective action as a display for use by the operator. The programmed instructions may contain models, algorithms and information from prior drilled boreholes, geological information about subsurface formations and the borehole drill path. In an alternative embodiment, the present invention provides an interactive system which displays dynamic drilling parameters for a variety of subsurface formations and downhole operating conditions for a number of different drill string combinations. The system is adapted to allow an operator to simulate drilling conditions for different formations and drilling equipment combinations. This system displays the extent of various dysfunctions as the operator is simulating the drilling conditions and displays corrective action for the operator to take to optimize drilling during such simulation.

Claims

1. A system for drilling from surface wellbores in subsurface formations from a surface , comprising:

(a) a drill string having

(i) a drilling assembly carrying a drill bit at a bottom end of the drilling assembly for drilling a wellbore,

(ii) a plurality of sensors carried by the drill string making measurements of a plurality of drill string parameters during drilling of the wellbore,

(iii) a processor carried by the drilling assembly computing from said measurements values of the drill string parameters, and

(iv) a transmitter associated with the drill string transmitting signals representative of the values of the drill string parameters to the surface; and

(b) a computer at the surface receiving the transmitted signals, said computer categorizing said received signals into a plurality of severity levels for each said drill string parameter, at least one such level indicative of a dysfunction for each said selected drill string parameter, said computer further displaying said categorized levels on a display.

2. The system according to claim 1, further comprising a model associated with the surface computer and wherein the surface computer utilizing said model determines at least one drilling parameters that will alleviate said dysfunctions when utilized for further drilling of the wellbore.

3. The system according to claim 2, wherein the model includes a predefined matrix correlating drilling parameters with the dysfunctions.

4. The system according to claim 1, wherein the drill string parameters are selected from a group consisting of bending moment, radial motion, axial motion, rotational motion, acceleration.

5. The system according to claim 1, wherein the drill string parameters are selected from a group consisting of bit bounce, torque, shock, vibration, pressure, rotation, pressure anomaly, acceleration, bit side force, mud motor condition, differential pressure, bearing condition, stick-slip, whirl, and bending moment.

6. The system according to claim 1, wherein the transmitter communicates via a medium selected from a group consisting of electromagnetic, tubing acoustic, fluid acoustic, mud pulse, fiber optics, and electric conductor.

7. The system according to claim 1, wherein the downhole sensors are selected from the group comprising, accelerometer, magnetometer, gyroscopes, strain gage, force on bit sensors, and drill bit wear sensor.

8. The system according to claim 2, wherein the drilling parameters are selected from the group consisting of weight-on-bit, fluid flow rate, drill bit rotational speed, drilling fluid viscosity, and drilling fluid density.

9. The system according to claim 2, wherein the surface computer periodically updates the model based on the received signals.

10. The system according to claim 1, further comprising a data base for use by the surface computer, said data base containing information selected from a group consisting of information about preexisting wellbores, offset wellbores, seismic surveys, and geological structures of subsurface formations.

11. A simulator for simulating drilling of a borehole having a given borehole profile and drilled by a given bottom hole assembly (BHA), said system comprising:

(a) a computer;

(b) a memory associated with said computer for storing therein programmed instructions; and

(c) a model associated with said computer, said model having defined therein parameters relating to the BHA and the borehole profile and a functional relationship that correlates selected BHA parameters with selected drilling parameters for the given BHA and the borehole profile,

and wherein said computer upon the input of a set of drilling parameters thereto utilizes said program and provides expected values of the selected BHA parameters and their severity levels.

12. The simulator according to claim 11, wherein one said severity level represents a dysfunction for each of the selected BHA parameters and wherein the computer further determines which f the selected drilling parameters are required to be changed to alleviate the dysfunctions.

13. The simulator according to claim 11, wherein the simulator includes a visual display and the computer displays the severity level of the selected BHA parameters, the drilling parameters and drilling parameters required to be changed.

14. The system according to claim 11, wherein the BHA parameters are selected from the group consisting of bit bounce, torque, shock, vibration, rotation, stick-slip, whirl, bending moment, backward rotation, pressure anomaly, acceleration, drill bit side force, mud motor condition, pressure differential across mud motor, condition of a bearing assembly in the BHA, and drill bit condition.

15. The system according to claim 11, wherein the drilling parameters are selected from group consisting of weight-on-bit, fluid flow rate, drilling fluid viscosity, drilling fluid density, and drill bit rotational speed.

24. The system according to claim 13, wherein the drilling efficiency is a function of rate of penetration of the drilling assembly into the subsurface formations and the operating life of at least one component of the drilling assembly.

16. A method of drilling an oilfield wellbore with a drilling system having a drilling assembly and a drill bit at an end thereof at enhanced drilling rates and with extended drilling assembly life, said drilling assembly conveyable with a tubing into the wellbore, said drilling assembly containing a plurality of downhole sensors for determining parameters relating to the formations surrounding the wellbore and the condition of the drilling assembly elements, comprising:

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

(b) initiating drilling of the wellbore with the drilling assembly utilizing a plurality of known initial drilling parameters;

(c) determining from the downhole sensors, during drilling of the wellbore, dysfunctions relating to selected drilling assembly parameters;

(d) providing a computer at the surface and a model that correlates the drilling assembly parameters to the drilling parameters and wherein the computer utilizing said model determines specific drilling parameters that when changed for further drilling of the wellbore will alleviate dysfunctions relating to the drilling assembly; and

(e) further drilling the wellbore by changing at least one of the specific drilling parameters to improve the overall drilling efficiency.

17. A method of drilling a wellbore utilizing a drill string having a drill bit at an end thereof, comprising:

(a) making measurements relating to a plurality of drill string parameters during drilling of the wellbore;

(b) determining downhole severity of the drill string parameters from the measurements;

(c) transmitting data to the surface corresponding to the severity of the drill string parameters;

(d) determining at the surface by a computer and by utilizing a model at least one drilling parameter which when changed will alleviate the dysfunctions relating to a drill string parameter during continued drilling of the wellbore; and

(e) continuing drilling of the wellbore by changing the at least one drilling parameter.

18. A system for drilling wellbores in subsurface formations from the surface, comprising:

(a) a drill string having

(i) a drilling assembly carrying a drill bit at a bottom end of the drilling assembly for drilling a wellbore,

(ii) a plurality of sensors carried by the drilling assembly making measurements of a plurality of drilling assembly parameters during drilling of the wellbore,

(iii) a processor carried by the drilling assembly computing from said measurements values of drilling assembly parameters, and

(iv) a transmitter associated with the drill string transmitting signals representative of the drilling assembly parameters to the surface; and

(b) a surface computer receiving the transmitted signals, said computer determining from said received signals and a model provided thereto values of at least one drilling parameter that when utilized for continued drilling of the wellbore would improve the drilling efficiency.

19. The system according to claim 18, wherein the drilling assembly parameters are selected from a group consisting of bit bounce, torque, shock, vibration, rotation, stick-slip, whirl, bending moment, backward rotation, pressure anomaly, acceleration, drill bit side force, mud motor condition, pressure differential across mud motor, condition of a bearing assembly in the BHA, and drill bit condition.

20. The system according to claim 18, wherein the drilling parameters are selected from group consisting of weight-on-bit, fluid flow rate, drilling fluid viscosity, drilling fluid density, and drill bit rotational speed.

21. The system according to claim 20, wherein the computer utilizes at least one well profile parameter and at least one drilling assembly descriptor provided to said computer to determine the at least one drilling parameter.

22. The system according to claim 21, wherein the at least one well profile parameter is selected from a group consisting of a lithological parameter, friction and inclination of the drilling assembly.

23. The system according to claim 22, wherein the at least one drilling assembly descriptor is selected from a group consisting of a drilling assembly configuration, weight of the drilling assembly and length of the drilling assembly.

25. The system according to claim 18, wherein the drilling assembly further includes sensors measuring at least one drilling parameter during the drilling of the wellbore and transmitting signals representative of such measurements to the surface computer.

26. The system according to claim 25, wherein said surface computer determines the relative severity level of each said drilling assembly parameter and displays said severity level and value of at least one downhole measured drilling parameter on a display of the system.