Realtime control of a drilling system using the output from combination of an earth model and a drilling process model

• US 6,968,909 B2
• Filed: 02/11/2003
• Issued: 11/29/2005
• Est. Priority Date: 03/06/2002
• Status: Expired due to Term

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: Schlumberger Technology Corporation (SLB)
• Inventors: Meehan, Richard, Aldred, Walter D.
• Primary Examiner(s): Bagnell, David
• Assistant Examiner(s): SCHOEPPEL, ROGER J
• Application Number:
  US10/248,704
• Publication Number:
  US 20030168257A1
• Time in Patent Office: 1,022 Days
• Field of Search: 175/24, 175/26, 175/27, 175/40, 175/45, 175/48, 175/50, 175/61, 175/39, 175/57, 364/420, 731/50, 731/515, 202/9
• US Class Current: 175/26
• 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 49/003 by analysing drilling variables or conditions E21B49/005 takes precedence; systems specially adapted for monitoring a plurality of drilling variables or conditions E21B44/00

Abstract

A system is for controlling borehole operations using a computational drilling process model representing the combined effect of downhole conditions and the operation of a drillstring. The drilling process model is continually updated with downhole measurements made during a drilling operation. From the updated drilling process model, a set of optimum drilling parameters is determined and communicated to a surface equipment control system. Further, the system allows the surface equipment control system to automatically adjust current surface equipment control settings based on the updated optimum drilling parameters. Various control scripts are generated and executed to inform the surface equipment control system based on a present drilling mode.

Claims

1. A method for controlling a downhole operation, comprising:

constructing a drilling process model to represent an interaction of downhole conditions with an operation of a drillstring;

obtaining a plurality of downhole drilling condition measurements during the downhole operation;

updating the drilling process model based on the downhole drilling condition measurements;

determining a plurality of optimum drilling parameter based on the updated drilling process model;

informing a surface equipment control system of the optimum drilling parameters;

iteratively repeating the steps of obtaining, updating, determining and informing during the downhole operation;

determining a drilling mode; and

executing a control sequence script based on the drilling mode.

2. The method as defined in claim 1, the step of constructing further comprising:

populating the drilling process model with parameters representing a geology of the formation surrounding the borehole.

3. The method as defined in claim 1, wherein the step of informing comprises transmitting an output of the control sequence script to the surface control equipment.

4. The method as defined in claim 1, wherein multiple control sequence scripts are ran concurrently.

5. The method as defined in claim 1, wherein the control sequence script performs an operation selected from the group of trip operation, rate of penetration control, fracture pressure control, directional drilling control, location drilling, sliding operation and fishing operation.

6. The method as defined in claim 1, wherein the drilling process model comprises an earth model.

7. The method as defined in claim 1, wherein the drilling process model comprises a hydraulics model.

8. The method as defined in claim 1, wherein the drilling condition measurements comprise formation evaluation measurements.

9. The method as defined in claim 1, the step of updating, further comprising:

updating the drilling process model with based on surface equipment operating data received from the surface equipment control system.

10. The method as defined in claim 1, further comprising:

automatically controlling operation of the surface equipment based on the optimum drilling parameters.

11. A downhole drilling system for determining optimum operating levels for operating surface drilling equipment comprising;

a surface equipment control system interface to communicate with a surface equipment control system

a drillstring for drilling a borehole;

a plurality of measurement devices located on the drillstring for obtaining downhole measurements during a downhole operation;

a downhole processing system containing software instructions stored in memory which when executed perform the steps of;

constructing a drilling process model to represent the interaction of downhole conditions with operation of the drillstring;

updating the drilling process model based on the downhole measurements;

determining a plurality of optimum drilling parameters based on the updated drilling process model;

informing the surface equipment control system of the optimum drilling parameters;

iteratively repeating the steps of updating, determining and informing during the downhole operation;

determining a drilling mode; and

executing a control sequence script based on the drilling mode.

12. The downhole drilling system of claim 11, the step of constructing further comprising:

populating the drilling process model with parameters representing a geology of the formation surrounding the borehole.

13. The downhole drilling system of claim 11, wherein the step of informing comprises transmitting an output of the control sequence script to the surface control equipment.

14. The downhole drilling system of claim 11, wherein multiple control sequence scripts are ran concurrently.

15. The downhole drilling system of claim 11, wherein the control sequence script performs an operation selected from the group of trip operation, rate of penetration control, fracture pressure control, directional drilling control, location drilling, sliding operation and fishing operation.

16. The downhole drilling system of claim 11, wherein the drilling process model comprises an earth model.

17. The downhole drilling system of claim 11, wherein the drilling process model comprises a hydraulics model.

18. The downhole drilling system of claim 11, wherein the drilling condition measurements comprise formation evaluation measurements.

19. The downhole drilling system of claim 11, the step of updating, further comprising:

updating the drilling process model with based on surface equipment operating data received from the surface equipment control system.

20. The downhole drilling system of claim 11, the processor performing the additional step of:

automatically controlling operation of the surface equipment based on the optimum drilling parameters.

21. The downhole drilling system of claim 11, further comprising;

a surface equipment control system interface for receiving and transmitting data between the surface equipment control system and the downhole processing system.