Radiation generator and power supply configuration for well logging instruments

Patent metadata

Field	Value
Publication number	US-10185053-B2
Application number	US-201615206561-A
Country	US
Kind code	B2
Filing date	Jul 11, 2016
Priority date	Aug 8, 2007
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

A well logging instrument includes a radiation generator and a high voltage power supply functionally coupled to the generator. The generator and the supply are longitudinally separated by a distance sufficient for emplacement of a radiation detector. At least a first radiation detector is disposed in a space between the generator and the supply. The instrument includes an electrical connection between the supply and the generator.

First claim

What is claimed is:

1. A well logging instrument, comprising:
at least one of an ionizing and nuclear radiation generator;
a high voltage power supply functionally coupled to the radiation generator, the generator being separated from the power supply; and
an electrical connection between the power supply and the generator;
wherein the generator and the power supply each extend in a direction corresponding to the longitudinal direction of the instrument, wherein the power supply and the generator are radially offset relative to each other.

2. The instrument of claim 1 further comprising at least a first radiation detector and wherein at least one of the connection and the power supply is positioned in a same radial plane of the instrument as the first radiation detector.

3. The instrument according to claim 2 , wherein the at least first radiation detector comprises a neutron detector.

4. The instrument according to claim 2 , wherein the at least first radiation detector comprises a spectral gamma ray detector.

5. The instrument according to claim 2 , wherein the generator, the at least first detector and the connection are disposed in a housing configured to move along a borehole drilled through subsurface formations.

6. The instrument of claim 5 , wherein the housing is configured to be conveyed along the borehole by at least one of wireline, slickline, threadedly coupled tubing and coiled tubing.

7. The instrument according to claim 2 , wherein the first radiation detector and the generator overlap when projected in a radial plane of the instrument.

8. The instrument according to claim 2 , wherein the generator contacts a wall of the instrument in a predetermined radial location when projected in the radial plane and the first radiation detector contacts the wall in the predetermined radial location as well.

9. The instrument according to claim 1 , wherein the electrical connection comprises a conductive material surrounded by an electrically insulating gas or and electrically insulating liquid.

10. The instrument according to claim 1 , wherein the radiation generator comprises a neutron generator.

11. The instrument according to claim 1 , wherein the generator and the power supply are positioned in the instrument so that they do not overlap when projected on a radial plane of the instrument.

12. The instrument according to claim 1 , wherein the generator contacts a wall of the instrument in a predetermined radial location when projected in a radial plane of the instrument, wherein the power supply contacts the wall of the instrument at a substantially opposite radial location when projected in the radial plane.

13. A method for evaluating formations traversed by a borehole, comprising:
generating electrical power to operate at least one of a nuclear and an ionizing radiation generator at a position separated from a position of the radiation generator along the borehole,
conducting the electrical power to the radiation generator via an electrical connection comprising a conductive material surrounded by an electrically insulating gas or and electrically insulating liquid;
operating the generator to emit high ionizing radiation into the formations; and
detecting radiation with at least one radiation detector.

14. The method of claim 13 wherein the detecting radiation comprises detecting neutrons.

15. The method of claim 14 , wherein the neutrons comprise at least one of high energy neutrons, thermal neutrons and epithermal neutrons.

16. The method of claim 13 , wherein the detecting radiation comprises detecting gamma rays.

17. The method of claim 16 , further comprising spectrally analyzing the detected gamma rays.

18. The method of claim 13 , further comprising detecting radiation at at least one position not between the position of the generating power and the radiation generator.

19. The method of claim 18 , wherein the detecting radiation at at least one position comprises detecting gamma rays or neutrons.

20. A well logging instrument, comprising:
at least one of an ionizing and nuclear radiation generator;
a high voltage power supply functionally coupled to the radiation generator, the generator being separated from the power supply;
an electrical connection between the power supply and the generator; and
at least a first radiation detector and wherein at least one of the connection and the power supply is positioned in a same radial plane of the instrument as the first radiation detector, and wherein the first radiation detector and the generator overlap when projected in a radial plane of the instrument.

Assignees

• Schlumberger Technology Corp

Inventors

• Roscoe Bradley A

Classifications

• G01V5/105 Primary

  the neutron source being of the pulsed type · CPC title

• G01V5/04

  specially adapted for well-logging · CPC title

• G01V5/10 Primary

  using neutron sources {(neutron generating tubes H05H5/00; neutron sources using isotopes G21G4/00)} · CPC title

• G01V5/104

  and detecting secondary Y-rays as well as reflected or back-scattered neutrons · CPC title