Edward R Dowd

US Patent:

7512292, Mar 31, 2009

Filed:

Sep 12, 2006

Appl. No.:

11/531145

Inventors:

Trevor MacDougall - Simsbury CT, US
Edward Dowd - Madison CT, US
Domino Taverner - Delray Beach FL, US

Assignee:

Weatherford/Lamb, Inc. - Houston TX

International Classification:

G02B 6/00
G02B 6/22
G02B 6/34

US Classification:

385 12, 385 24, 385 37, 385126

Abstract:

Methods and apparatus for discrete point temperature sensing include a temperature sensor that can be part of an array of temperature sensors for location in a wellbore. A single unitary ribbon-like structure can form the temperature sensor that has separate optical cores possessing different characteristics such that one core is unique from another core. Each core has a reflective grating disposed therein such that the wavelength of light reflected by the gratings is in response to temperature and any strain applied to the sensor from a surrounding environment. For some embodiments, the responses to strain from each of the gratings are similar while the responses from each of the gratings to temperature are dissimilar due to the different characteristics of the cores. These responses provided separately by each grating therefore enable compensation for strain in order to provide an accurate temperature measurement at the sensor.

US Patent:

7903908, Mar 8, 2011

Filed:

Mar 31, 2009

Appl. No.:

12/415635

Inventors:

Trevor MacDougall - Simsbury CT, US
Edward Dowd - Madison CT, US
Domino Taverner - Delray Beach FL, US

Assignee:

Weatherford/Lamb, Inc. - Houston TX

International Classification:

G02B 6/00
G02B 6/34

US Classification:

385 12, 385 24, 385 37, 385126

Abstract:

Methods and apparatus for discrete point temperature sensing include a temperature sensor that can be part of an array of temperature sensors for location in a wellbore. A single unitary ribbon-like structure can form the temperature sensor that has separate optical cores possessing different characteristics such that one core is unique from another core. Each core has a reflective grating disposed therein such that the wavelength of light reflected by the gratings is in response to temperature and any strain applied to the sensor from a surrounding environment. For some embodiments, the responses to strain from each of the gratings are similar while the responses from each of the gratings to temperature are dissimilar due to the different characteristics of the cores. These responses provided separately by each grating therefore enable compensation for strain in order to provide an accurate temperature measurement at the sensor.

US Patent:

8073293, Dec 6, 2011

Filed:

Jan 13, 2004

Appl. No.:

10/756183

Inventors:

Alan D. Kersey - South Glastonbury CT, US
Paul E. Sanders - Madison CT, US
Martin A. Putnam - Cheshire CT, US
Edward Michael Dowd - Madison CT, US

Assignee:

Weatherford, LAMB, Inc. - Houston TX

International Classification:

G02B 6/00
G02B 6/02

US Classification:

385 12, 385123

Abstract:

An optical sensor formed from an optical waveguide having at least one core surrounded by a cladding and a large diameter generally D-shaped portion is disclosed. Axial or compressive strain across the D-shaped cross section may be determined by measuring the change in polarization or birefringence of the light output from the sensor. A layer responsive to a parameter may be disposed on a flat portion of the D-shaped portion of the sensor. The refractive index of the layer changes and/or the layer applies a strain on the sensor in response to the parameter. Changes in the refractive index of the layer alters the light output from the sensor, which is measured over time and correlated to the parameter.

US Patent:

20120076452, Mar 29, 2012

Filed:

Dec 6, 2011

Appl. No.:

13/311854

Inventors:

Alan D. Kersey - South Glastonbury CT, US
Paul E. Sanders - Madison CT, US
Martin A. Putnam - Cheshire CT, US
Edward Michael Dowd - Madison CT, US

International Classification:

G02B 6/00
B24B 1/00
C03C 15/00
B23P 11/00

US Classification:

385 12, 294261, 451 28, 216 24, 294262

Abstract:

An optical sensor formed from an optical waveguide having at least one core surrounded by a cladding and a large diameter generally D-shaped portion is disclosed. Axial or compressive strain across the D-shaped cross section may be determined by measuring the change in polarization or birefringence of the light output from the sensor. A layer responsive to a parameter may be disposed on a flat portion of the D-shaped portion of the sensor. The refractive index of the layer changes and/or the layer applies a strain on the sensor in response to the parameter. Changes in the refractive index of the layer alters the light output from the sensor, which is measured over time and correlated to the parameter.

US Patent:

20160116331, Apr 28, 2016

Filed:

Dec 30, 2015

Appl. No.:

14/983994

Inventors:

- Houston TX, US
John J. GRUNBECK - Northford CT, US
James R. DUNPHY - South Glastonbury CT, US
Edward M. DOWD - Madison CT, US
David ABELLA - Higganum CT, US
Mark BAKER - Wallinford CT, US
Andrew S. KUCZMA - Clinton CT, US

International Classification:

G01H 9/00
G02B 6/02
G02B 6/44

Abstract:

Methods and apparatus for performing Distributed Acoustic Sensing (DAS) using fiber optics with increased acoustic sensitivity are provided. Acoustic sensing of a wellbore, pipeline, or other conduit/tube based on DAS may have increased acoustic sensitivity through fiber optic cable design and/or increasing the Rayleigh backscatter property of a fiber's optical core. Some embodiments may utilize a resonant sensor mechanism with a high Q coupled to the DAS device for increased acoustic sensitivity.