US 9,255,836 B2 · Fiber optic cable for distributed acoustic sensing with increased acoustic sensitivity

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.

Claims40

Dependent claims

A fiber optic cable used for distributed acoustic sensing (DAS), comprising:

an outer tube;
an inner tube surrounded by the outer tube;
and
one or more optical fibers surrounded by the inner tube, wherein the one or more optical fibers have increased acoustic sensitivity compared to a standard optical fiber, wherein at least one of the one or more optical fibers have a smaller diameter compared to the standard optical fiber, and wherein, upon application of pressures created by acoustic waves, the smaller diameter provides for increased response of the fibers when compared to the standard optical fiber.

1 more element

Dependencies are inferred from the claim text.

Facts

Application

13/307,765Filed 30 Nov 2011 · continuation

Priority

17 Jun 2010

Published

US 2012/0111104 A110 May 2012

Granted

9 Feb 2016

Term ends

Not estimatedThe source records don’t support an estimate.

Classification10 codes

G01H 9/004
Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means: using fibre optic…
E21B 47/135
By electromagnetic energy, e.g. radio frequency: using light waves, e.g. infrared or ultraviolet waves
G02B 6/02342
Plurality of longitudinal structures extending along optical fibre axis, e.g. holes: characterised by cladding features, i.e. light confining region
G02B 6/02395
Optical fibres with cladding with or without a coating: glass optical fibre with a protective coating, e.g. two layer polymer coating deposited…

Fiber optic cable for distributed acoustic sensing with increased acoustic sensitivity

Life of this patent

Fiber optic cable for distributed acoustic sensing with increased acoustic sensitivity

Life of this patent

Abstract

Claims40