Leadless sub assembly for downhole detection system

• US 6,712,160 B1
• Filed: 10/26/2001
• Issued: 03/30/2004
• Est. Priority Date: 11/07/2000
• Status: Expired due to Term

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Schultz, Roger L., Osborne, Andrew J. Jr., De Jesus, Orlando
• Primary Examiner(s): SCHOEPPEL, ROGER J
• Application Number:
  US10/040,294
• Time in Patent Office: 886 Days
• Field of Search: 175/40, 175/48, 166/250.01, 340/853--85
• US Class Current: 175/48
• CPC Class Codes: E21B 12/02 Wear indicators
• CPC Class Codes: E21B 2200/22 Fuzzy logic, artificial intelligence, neural networks or the like
• CPC Class Codes: E21B 41/0085 Adaptations of electric power generating means for use in boreholes
• 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 47/18 through the well fluid , e.g. mud pressure pulse telemetry
• CPC Class Codes: E21B 47/22 by negative mud pulses using a pressure relieve valve between drill pipe and annulus

Abstract

A drill string is equipped with a down hole sub assembly which contains sensors to detect equipment condition during drilling. The sub assembly has no electrical communication with the drill bit itself, and the sensors detect drill bit condition from vibrations or strain or other detectable phenomena. Sensors in the bit itself are not needed.

Claims

1. A system for monitoring drill bit performance, comprising:

a drill string mechanically connecting a drill bit to the surface; and

a sub assembly on the lower end of said string above said drill bit;

wherein said sub assembly includes one or more sensors, and circuitry which processes the output of said one or more sensors to detect and signal failing of the drill bit, without relying on sensors in the drill bit.

2. The system of claim 1, wherein said circuitry comprises an adaptive neural network.

3. The system of claim 1, wherein said sensors measure axial strain.

4. The system of claim 1, wherein said sensors measure vibrational frequency.

5. The system of claim 1, wherein drill bit failure is signaled to a surface operator.

6. A system for monitoring drill bit performance, comprising:

a drill string mechanically connecting a drill bit to the surface;

a sub assembly on the lower end of said string above said drill bit;

a detection platform on said sub assembly which receives data from one or more sensors;

wherein said sub assembly is connected to predict and signal failure of the drill bit, without any connection to sensors in the drill bit.

7. The system of claim 6, wherein said sub assembly predicts failure using an adaptive neural network.

8. The system of claim 6, wherein said sensors measure axial strain.

9. The system of claim 6, wherein said sub assembly predicts failure by monitoring relative changes in data collected by said sensors.

10. The system of claim 6, wherein drill bit failure is signaled to a surface operator.

11. A method of operating a drill rig, comprising the steps of:

monitoring a signal transmitted from a downhole instrumented sub assembly, said sub assembly having no electrical communication with sensors in an attached drill bit, and said sub assembly having at least one sensor thereon;

halting drilling when said signal indicates an impending failure condition.

12. The method of claim 11, wherein said at least one sensor measures axial strain.

13. The method of claim 11, wherein sensor data is analyzed by an adaptive math model.

14. The method of claim 11, wherein said sub assembly has no electrical communication with said attached drill bit.

15. The method of claim 11, wherein said signal is transmitted to the operator by varying the pressure of drilling mud.

16. A method of operating a drill rig, comprising the steps of:

on a drill string having a drill bit, monitoring a signal transmitted from one or more downhole sensors, said sensors located on a sub assembly which has no electrical communication with sensors in said drill bit;

taking a predetermined action when said signal indicates a change in downhole equipment conditions.

17. The method of claim 16, wherein said predetermined action is to halt normal drilling.

18. The method of claim 16, wherein said step of monitoring is performed by an adaptive filter located on said sub assembly.

19. The method of claim 16, wherein said sub assembly has no electrical communication with said drill bit.