Tool for azimuthal resistivity measurement and bed boundary detection

• US 9,851,467 B2
• Filed: 08/30/2016
• Issued: 12/26/2017
• Est. Priority Date: 08/08/2006
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Bittar, Michael S.
• Primary Examiner(s): Aurora, Reena
• Application Number:
  US15/252,153
• Publication Number:
  US 20160370490A1
• Time in Patent Office: 483 Days
• Field of Search: 324337
• CPC Class Codes: E21B 47/026 of penetrated ground layers
• CPC Class Codes: G01V 1/28 Processing seismic data, e.g. for interpretation or for event detection G01V1/48 takes precedence
• CPC Class Codes: G01V 2210/54 Borehole-related corrections
• CPC Class Codes: G01V 3/28 using induction coils
• CPC Class Codes: G01V 3/30 operating with electromagnetic waves

Abstract

Systems and methods for performing bed boundary detection and azimuthal resistivity logging using a logging tool with a pair of tilted receiver antennas having a midpoint on a longitudinal axis of the logging tool, a first pair of transmitter antennas symmetrically spaced from said midpoint, and a third tilted receiver antenna positioned farther from said midpoint than the transmitter antennas. Method embodiments include energizing each transmitter antenna of the first pair in a firing sequence and obtaining, responsive to the energizing, measurements with a pair of tilted receiver antennas equally spaced from said midpoint. Methods may also include obtaining, responsive to energizing of a more distant one of the first pair of transmitter antennas, measurements with a third tilted receiver antenna positioned farther from the midpoint than the transmitter antennas.

Claims

1. A logging tool that comprises:

a pair of tilted receiver antennas having a midpoint on a longitudinal axis of the logging tool;

a first pair of transmitter antennas symmetrically spaced from said midpoint; and

a third tilted receiver antenna positioned farther from said midpoint than said transmitter antennas.

2. The logging tool of claim 1, wherein said transmitter antennas are coaxial.

3. The logging tool of claim 1, further comprising:

a processor that processes measurements from the pair of tilted receiver antennas to determine measurements of formation resistivity, and that further processes measurements from the third tilted receiver antenna to determine a bed boundary indicator.

4. The logging tool of claim 3, wherein the processor processes said measurements from the pair of tilted receiver antennas as a function of azimuthal orientation to determine at least one of a vertical resistivity, a horizontal resistivity, and a formation dip angle.

5. The logging tool of claim 1, further comprising:

a second pair of transmitter antennas symmetrically spaced from said midpoint at twice the distance of the first pair of transmitter antennas.

6. The logging tool of claim 5, further comprising:

a third pair of transmitter antennas symmetrically spaced from said midpoint at three times the distance of the first pair of transmitter antennas.

7. The logging tool of claim 6, wherein the third tilted receiver antenna is spaced at four times the distance of the first pair of transmitter antennas.

8. A logging method that comprises:

on a resistivity logging tool having a first pair of transmitter antennas symmetrically spaced from a midpoint on a longitudinal axis of the logging tool, energizing each transmitter antenna of said first pair in a firing sequence;

obtaining, responsive to said energizing, measurements with a pair of tilted receiver antennas equally spaced from said midpoint; and

obtaining, responsive to energizing of a more distant one of the first pair of transmitter antennas, measurements with a third tilted receiver antenna positioned farther from said midpoint than said transmitter antennas.

9. The logging method of claim 8, wherein said transmitter antennas are coaxial.

10. The logging method of claim 8, further comprising:

processing measurements from the pair of tilted receiver antennas to determine measurements of formation resistivity; and

processing measurements from the third tilted receiver antenna to determine a bed boundary indicator.

11. The logging method of claim 10, wherein the processing of measurements from the pair of tilted receiver antennas is performed as a function of azimuthal orientation to determine at least one of a vertical resistivity, a horizontal resistivity, and a formation dip angle.

12. The logging method of claim 8, wherein said firing sequence includes energizing each of a second pair of transmitter antennas symmetrically spaced from said midpoint at half the distance of the first pair of transmitter antennas.

13. The logging method of claim 8, wherein said firing sequence includes energizing each of a second pair of transmitters symmetrically spaced from said midpoint at two-thirds the distance of the first pair of transmitter antennas and each of a third pair of transmitter antennas symmetrically spaced from said midpoint at one-third the distance of the first pair of transmitter antennas.

14. The logging tool of claim 13, wherein the third tilted receiver antenna is spaced at four times the distance of the third pair of transmitter antennas.