Method of drilling in response to looking ahead of the bit

• US 6,791,469 B1
• Filed: 10/04/2002
• Issued: 09/14/2004
• Est. Priority Date: 03/27/2000
• Status: Expired due to Term

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Rao, M. Vikram, Rodney, Paul F.
• Primary Examiner(s): WONG, ALBERT KANG
• Application Number:
  US10/264,731
• Time in Patent Office: 711 Days
• Field of Search: 367/82, 175/40, 175/41, 175/50, 175/26, 340/853.6, 181/102, 181/106, 702/9
• US Class Current: 340/853.6
• CPC Class Codes: E21B 49/00 Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
• 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
• CPC Class Codes: G01V 1/44 using generators and receivers in the same well G01V1/52 takes precedence

Abstract

A method for improving ROP and reducing hazards in drilling subterranean wells by using an acoustical system 15 to look ahead of the drill bit 14, detects and analyzes geologic features ahead of the bit 14 which may be qualified as drilling hazards 17. Detection of such hazards 17 may facilitate use of more aggressively penetrating bits 14 such as PDC bits as opposed to roller cone bits. In addition, other drilling parameters may be adjusted to improve ROP due to the ability to timely respond to identified hazards 17 before they may be detrimentally encountered by the bit 14. The acoustic system 15 may look ahead of the bit 14 by at least 100 meters, using propagated acoustic waves 19 to locate changes in acoustic impedance which may represent drilling hazards 17. In addition, bulk resistivity ahead of the bit 14 may also be measured and used to locate drilling hazards 17. The measured properties of the investigated formation may facilitate optimizing the design and operation of a drilling program so as to improve the rate of penetration.

Claims

1. A method of increasing the rate of penetration when drilling a subterranean well through formations using a drill string including a drill bit, comprising:

generating an acoustic signal downhole along a drill string and propagating the acoustic signal outward into a formation;

inducing an electromagnetic signal in the formation in response to the acoustic signal;

receiving the induced electromagnetic signal downhole along the drill string;

transmitting a downhole signal functionally related to the electromagnetic signal to the surface;

processing said downhole signal to generate processed data; and

altering one or more drilling parameters in response to the processed data.

2. The method as defined in claim 1, wherein processing said downhole signal includes calculating resistivity of the formation.

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

comparing the processed data to known formation characteristics.

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

displaying drilling parameters along with the characteristics of the processed data.

5. The method as defined in claim 1, wherein altering the one or more drilling parameters includes modifying the bit selection.

6. The method as defined in claim 1, wherein altering the one or more drilling parameters includes changing weight on bit while drilling.

7. The method as defined in claim 1, wherein altering the one or more drilling parameters includes changing rotary speed of the drill bit while drilling.

12. The method as defined in claim 1, wherein altering the one or more drilling parameters includes at least one of changing weight on drill bit while drilling and changing rotary speed of the drill bit while drilling.

8. A method of increasing the rate of penetration when drilling a subterranean well through formations using a drill string including a drill bit, comprising:

generating an acoustic signal downhole along a drill string and propagating the acoustic signal outward into a formation; and

inducing an electromagnetic signal in the formation in response to the acoustic signal;

receiving the induced electromagnetic signal downhole along the drill string;

transmitting a downhole signal functionally related to the electromagnetic signal to the surface;

processing said downhole signal to generate processed data indicative of at least one of pore preserve and resistivity of the formation; and

altering one or more drilling parameters in response to the processed data.

9. The method as defined in claim 8, further comprising:

comparing the processed data to known formation characteristics.

10. The method as defined in claim 8, further comprising:

displaying drilling parameters along with the characteristics of the processed data.

11. The method as defined in claim 8, wherein altering the one or more drilling parameters includes modifying the bit selection.

13. A method of increasing the rate of penetration when drilling a subterranean well through formations using a drill string including a drill bit, comprising:

generating an acoustic signal downhole along a drill string and propagating the acoustic signal outward into a formation;

inducing an electromagnetic signal in the formation in response to the acoustic signal;

receiving the induced electromagnetic signal downhole along the drill string;

transmitting a downhole signal functionally related to the electromagnetic signal to the surface;

processing said downhole signal to generate processed data; and

altering at least one of bit selection, weight on bit while drilling, and rotating speed while drilling in response to the processed data.

14. The method as defined in claim 13, wherein processing said downhole signal includes calculating resistivity of the formation.

15. The method as defined in claim 13, further comprising:

comparing the processed data to known formation characteristics.

16. The method as defined in claim 13, further comprising:

displaying drilling parameters along with the characteristics of the processed data.