Parameter sensing and monitoring

Abstract

Apparatus and method for monitoring at least one parameter associated with an elongate structure are disclosed. The apparatus may include at least one elongate support body element arranged along a longitudinal structure axis associated with an elongate target structure; and at least one optic fibre element arranged substantially helically along a longitudinal body element axis associated with the at least one support body element. A method of manufacturing flexible pipe body is also disclosed.

1 . Apparatus for monitoring at least one parameter associated with an elongate structure, comprising:
 at least one elongate support body element arranged along a longitudinal structure axis associated with an elongate target structure; and   at least one optic fibre element arranged substantially helically along a longitudinal body element axis associated with the at least one support body element.   
     
     
         2 . The apparatus as claimed in  claim 1  wherein the support body element is arranged substantially straight along said a longitudinal structure axis. 
     
     
         3 . The apparatus as claimed in  claim 1  wherein the support body element is arranged substantially helically along said longitudinal structure axis. 
     
     
         4 . The apparatus as claimed in  claim 1 , further comprising:
 each optic fibre element is repeatedly or continuously bonded to said at least one body element.   
     
     
         5 . The apparatus as claimed in  claim 1 , further comprising:
 each optic fibre element is arranged about an external surface of the at least one body element.   
     
     
         6 . The apparatus as claimed in  claim 1 , further comprising:
 each optic fibre element is arranged in a grooved region extending substantially helically about an external surface of the at least one body element.   
     
     
         7 . The apparatus as claimed in  claim 1 , further comprising:
 the at least one body element and the at least one fibre element are arranged to allow the target structure to be subjected to a strain around a Radius R said a strain exceeding a normal breaking strain associated with the fibre element.   
     
     
         8 . The apparatus as claimed in  claim 1 , further comprising:
 the at least one body element has a diameter small enough to allow a minimum of one turn of the fibre element to satisfy a discrimination length of a sensing system connected to the fibre element.   
     
     
         9 . The apparatus as claimed in  claim 1 , further comprising:
 the fibre element is arranged closely proximate to the body element.   
     
     
         10 . The apparatus as claimed in  claim 1  wherein the body element is elastomeric. 
     
     
         11 . The apparatus as claimed in  claim 1 , further comprising:
 the at least one fibre element is arranged whereby the minimum bend radius of the fibre is not exceeded and a fibre boundary does not exceed a critical angle of the fibre element.   
     
     
         12 . The apparatus as claimed in  claim 1 , further comprising:
 the substantially helical arrangement of the at least one fibre element follows a substantially identical axial traverse along a whole length of the body element.   
     
     
         13 . The apparatus as claimed in  claim 1 , further comprising:
 the at least one body element comprises a rod member having a constant cross section, a shape of the cross section being a rectangle with rounded corners or an oval or a circle or an ellipse.   
     
     
         14 . The apparatus as claimed in  claim 13  wherein the rod member is a metallic or meric or composite material. 
     
     
         15 . The apparatus as claimed in  claim 13 , further comprising:
 the rod member is temporarily attached or permanently bonded or directly incorporated to the target structure.   
     
     
         16 . The apparatus as claimed in  claim 1 , further comprising:
 a sensing system connectable to at least one end of the fibre element.   
     
     
         17 . The apparatus as claimed in  claim 1  wherein the at least one parameter comprises strain or temperature. 
     
     
         18 . The apparatus as claimed in  claim 1  wherein the target structure comprises a portion of one of a bridge or road surface or lamp post or wind turbine blade or yacht mast or suspended power cable or aircraft body piece. 
     
     
         19 . The apparatus as claimed in  claim 1 , further comprising:
 the elongate target structure comprises flexible pipe body comprising a fluid retaining layer and at least one armour layer.   
     
     
         20 . The apparatus as claimed in  claim 19 , further comprising:
 the at least one body element comprises a substrate member wound at a pitch matching a pitch of winding in the armour layer, the fibre element being arranged substantially helically around an outer surface of the substrate member.   
     
     
         21 . The apparatus as claimed in  claim 19 , further comprising:
 the at least one body element comprises a hollow body member wound at a pitch matching a pitch of winding in the armour layer, the fibre element being arranged substantially helically around an inner surface of the hollow body member.   
     
     
         22 . The apparatus as claimed in  claim 19 , further comprising:
 a first and second end fitting terminating a respective first and second end of the flexible pipe body, the at least one fibre element extending at least between the first and second end fittings or between a portion of the pipe body between the first and second end fittings or between an intermediate point along the flexible pipe body and a one of the first and second end fittings.   
     
     
         23 . The apparatus as claimed in  claim 19 , further comprising: the flexible pipe body comprises pipe body of a flexible pipe comprising a riser or flowline or jumper. 
     
     
         24 . A method of monitoring at least one parameter associated with an elongate structure, comprising the steps of:
 providing at least one elongate support body element, comprising at least one optic fibre element arranged substantially helically along a longitudinal body element axis associated with the body element, along a longitudinal structure axis associated with an elongate target structure; and   via a sensing system, monitoring at least one characteristic associated with the fibre element, said characteristic being indicative of a parameter associated with the elongate structure.   
     
     
         25 . The method as claimed in  claim 24 , further comprising:
 providing the body element comprises laying the body element substantially straight along the structure axis.   
     
     
         26 . The method as claimed in  claim 24 , further comprising:
 providing the body element comprises helically winding the body element along the structure axis.   
     
     
         27 . A method of manufacturing flexible pipe body comprising:
 providing a fluid retaining layer;   providing at least one armour layer; and   providing at least one elongate support body element, comprising at least one optic fibre element arranged substantially helically along a longitudinal body element axis associated with the body element, along a longitudinal pipe body axis associated with the pipe body.   
     
     
         28 . The method as claimed in  claim 27 , further comprising:
 providing the support body element by helically winding the support body element as a winding of the armour layer.   
     
     
         29 . Apparatus for monitoring at least one parameter associated with an elongate structure, comprising:
 at least one optic fibre element arranged substantially helically along a longitudinal body element axis of an elongate support body element, said body element being arranged along a longitudinal structure axis; wherein   a length of the fibre element between first and second planes spaced apart along, and perpendicular to, the longitudinal structure axis, is greater than a comparable length of the optic fibre element wound, at a predetermined pitch, between the first and second planes.   
     
     
         30 . The apparatus as claimed in  claim 29  wherein said predetermined pitch comprises a helical pitch of the fibre element arranged along the body element. 
     
     
         31 . The apparatus as claimed in  claim 29  wherein said predetermined pitch comprises a largest possible pitch small enough to allow a minimum of one turn of the fibre element to satisfy a discrimination length of a sensing system connected to the fibre element. 
     
     
         32 . The apparatus as claimed in  claim 29  wherein said predetermined pitch is a pitch which maintains a bend radius of the fibre element equal to or below a minimum bend radius and a fibre boundary equal to or below a critical angle of the fibre element. 
     
     
         33 . The apparatus as claimed in  claim 29  wherein said elongate structure comprises a flexible pipe comprising an armour layer comprising helically wound armour wire windings, said predetermined pitch comprising a pitch of winding of said wire windings. 
     
     
         34 . (canceled) 
     
     
         35 . (canceled)