Schlumberger Technology Corporation

Ian Peirce

Rogerio Tadeu Ramos

Masafumi Fukuhara

Damon Richard Roberts

Yamid Pico

Martin P W Jones

Richard D G Roberts

Peter Coupe

Dmitry Belov

Evgeniya Myalo Deger

A system and method are provided for determining wall thickness of a structure such as a metallic pressurized pipe. The system includes an optical fiber having a plurality of Fiber Bragg Gratings (FBGs), and a mounting for securing the FBGs over discrete portions of the exterior surface of the pipe such that strain in the pressurized pipe wall is transmitted to the FBGs. The system further includes a light source and a light sensor coupled to an end of the optical fiber. The light sensor converts light reflected back from the FBGs into electrical signals that a digital processor converts into strain measurements. The FBGs are mounted around portions of the pipe expected to have significant metal loss as well as portions of the pipe expected to have negligible metal loss. The method includes at least one of comparing relative strains at locations with negligible metal loss to those with significant metal loss to accurately determine the thickness of the wall with metal loss; compensating for temperature effects by considering relative strains at areas of the pipe with and without metal loss; and measuring axial strain on the pipe with one or more of the FBGs to correct for at least one of bending and torsion effects on hoop strain.

System and method for uniform and localized wall thickness measurement using fiber optic sensors

Structural member bend radius sensor apparatuscomprises three fibre Bragg grating (FBG) strain sensorsprovided within three optical fibres. The optical fibresand the FBGsare embedded within a part-cylindrical shaped carrier member. The fibresare provided at three spaced locations across the shaped carrier memberso that, in use, the three respective FBG strain sensors will be located at three different angular positions around the circumference of the structural member (pipe). Structural member shape measurement apparatuscomprises four bend radius sensor apparatusprovided at four bend radius measurement positions along the pipe. The four bend radius sensor apparatusshown share their optical fibres, and a single shaped carrier member. The shape measurement apparatusfurther comprises FBG interrogation apparatus

Structural member bend radius and shape sensor and measurement apparatus

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Hampshire, United Kingdom

Ian Peirce