Optical transducer with integrated feedthrough

Patent metadata

Field	Value
Publication number	US-9588314-B2
Application number	US-201514941836-A
Country	US
Kind code	B2
Filing date	Nov 16, 2015
Priority date	Mar 8, 2012
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

An optical transducer is provided. A “measuring” portion of the transducer may be exposed to a high pressure and fluids when the optical transducer is deployed (e.g., in a wellbore or other industrial setting). The transducer may include an optical waveguide with a first portion that forms a first seal that isolates an “instrumentation” portion of the transducer from exposure to the high pressure and fluids to which the measuring portion may be exposed. The transducer may also include a second seal with a “stack” of material elements that contact a second portion of the optical waveguide to also isolate the instrumentation portion of the transducer from exposure to the high pressure and fluids to which the measuring portion may be exposed.

First claim

The invention claimed is:

1. A feedthrough assembly, comprising:
at least one conductive line; and
a feedthrough element configured to isolate a first portion of the feedthrough assembly from a second portion of the assembly, wherein the feedthrough element comprises:
a housing having a bore extending therethrough;
a first seal formed by a first portion of the at least one conductive line in contact with a mating surface of the bore of the housing;
a second seal formed by contact between an arrangement of sealing elements with a second portion of the at least one conductive line and an inner surface of the housing; and
a member in contact with a third portion of the at least one conductive line and configured to apply a first pre-loading force to promote sealing of at least the first seal.

2. The assembly of claim 1 , wherein the third portion of the at least one conductive line has a greater outer diameter than the first and second portions of the at least one conductive line.

3. The assembly of claim 1 , wherein a second pre-loading force is applied to promote sealing of the second seal by expanding the sealing elements.

4. The assembly of claim 3 , wherein the sealing elements comprise v-seals and wherein the feedthrough element further comprises a v-seal pre-loader configured to apply the second pre-loading force.

5. The assembly of claim 4 , wherein:
the v-seal pre-loader comprises one or more retention members;
the feedthrough element further comprises another housing disposed around the member and the third portion of the at least one conductive line; and
the other housing comprises a flange configured to be retained axially by the one or more retention members of the v-seal pre-loader.

6. The assembly of claim 5 , wherein the other housing further comprises a collar configured to hold the member in place.

7. The assembly of claim 5 , wherein a center of the other housing is shifted radially with respect to at least one of a center of the bore or a center of the v-seal pre-loader.

8. The assembly of claim 5 , wherein the flange is welded in position.

9. The assembly of claim 1 , wherein a portion of the mating surface of the bore for forming the first seal is undercut to reduce at least one of a magnitude or a gradient of a stress distribution in a region transitioning from high stress to no stress along the first portion of the at least one conductive line.

10. The assembly of claim 1 , wherein the at least one conductive line comprises a large diameter optical waveguide and wherein the first portion comprises a frustoconical glass plug.

11. The assembly of claim 1 , wherein a first sealing element in the arrangement of sealing elements comprises a different material than a second sealing element in the arrangement.

12. An optical transducer, comprising:
at least one optical waveguide comprising at least one sensing element disposed therein;
a feedthrough element configured to isolate a first portion of the transducer in communication with the sensing element from a second portion of the transducer containing the sensing element, wherein the feedthrough element comprises a seal formed by a first portion of the optical waveguide in contact with a surface of a bore extending through a housing of the feedthrough element; and
a member in contact with a second portion of the optical waveguide and configured to apply a pre-loading force to promote sealing of the seal, wherein the second portion of the optical waveguide has a greater outer diameter than the first portion of the optical waveguide.

13. The optical transducer of claim 12 , wherein a portion of a surface of the member is undercut to reduce at least one of a magnitude or a gradient of a stress distribution in a region transitioning from high stress to no stress along the second portion of the optical waveguide.

14. The optical transducer of claim 12 , further comprising a bellows assembly containing a fluid, wherein the bellows assembly is configured to move axially in response to changes in pressure external to the optical transducer and wherein the changes in external pressure are transferred via the fluid to the sensing element.

15. The optical transducer of claim 12 , wherein the optical waveguide is a monolithic structure providing both sensing and feedthrough aspects of the optical transducer.

16. The optical transducer of claim 12 , wherein the second portion of the optical waveguide is flared.

17. The optical transducer of claim 12 , further comprising another housing disposed around the member and the second portion of the optical waveguide, wherein the other housing is retained axially in a manner allowing a center of the other housing to be shifted radially with respect to a center of the bore extending through the housing of the feedthrough element.

Assignees

• Weatherford Tech Holdings Llc

Inventors

• Dunphy James R
• Grunbeck John J
• Boemmels Bryan
• Daigle Guy A

Classifications

• G02B6/4248

  Feed-through connections for the hermetical passage of fibres through a package wall (see provisionally also G02B6/4428) · CPC title

• G02B6/4251

  Sealed packages (G02B6/4248 takes precedence) · CPC title

• G02B6/022

  using mechanical stress, e.g. tuning by compression or elongation, special geometrical shapes such as "dog-bone" or taper (G02B6/02204 takes precedence; optical modulation using photo-elastic effect G02F1/0131) · CPC title

• G02B6/4428 Primary

  Penetrator systems in pressure-resistant devices · CPC title

• G02B6/02204

  using thermal effects, e.g. heating or cooling of a temperature sensitive mounting body (optical modulation using thermo-optic effect G02F1/0147) · CPC title