Strake systems and methods

Abstract

There is disclosed a system comprising a structural element, at least one helical strake about the structural element, and at least one ramp to provide a transition from the structural element to the helical strake.

1 . A system comprising: 
 a structural element;    at least one helical strake about the structural element; and    at least one ramp to provide a transition from the structural element to the helical strake.    
   
   
       2 . The system of  claim 1 , wherein the structural element is selected from the group consisting of a shell, a collar, an oil flowline, a pipeline, a drilling riser, a production riser, a steel tubular, import and export risers, subsea pipelines, tendons for tension leg platforms, legs for traditional fixed and for compliant platforms, space-frame members for platforms, cables, umbilicals, mooring elements for deepwater platforms, hull structures for tension leg platforms and for spar type structures, and column structures for tension leg platforms and for spar type structures.  
   
   
       3 . The system of  claim 1 , wherein the structural element comprises a plurality of sections welded to each other.  
   
   
       4 . The system of  claim 1 , wherein the structural element comprises a plurality of sections threaded to each other.  
   
   
       5 . The system of  claim 1 , wherein the at least one helical strake about the structural element comprises at least three helical strakes about the structural element.  
   
   
       6 . The system of  claim 1 , wherein the at least one ramp comprises a plurality of ramps aligned along a longitudinal axis of the structural element, the ramps adapted to interface with a stinger and/or a roller.  
   
   
       7 . The system of  claim 1 , wherein the at least one ramp comprises a first set of ramps and a second set of ramps, the first set and the second set aligned along a longitudinal axis of the structural element, the first set adapted to interface with a first roller, and the second set adapted to interface with a second roller azimuthally spaced apart from the first roller.  
   
   
       8 . The system of  claim 1 , wherein a first end of the at least one helical strake is attached to a first collar, and a second end of the at least one helical strake is attached to a second collar, the first collar and the second collar attached about the structural element.  
   
   
       9 . A method of installing a structural element in a body of water comprising: 
 attaching at least one helical strake about the structural element;    attaching at least one ramp to the structural element and/or the at least one helical strake, the at least one ramp to provide a transition from the structural element to the helical strake; and    moving the structural element, the ramp, and the strake over a roller, so that the at least one ramp provides a transition from the structural element to the helical strake where the roller interfaces with the structural element, the ramp, and the strake.    
   
   
       10 . The method of  claim 9 , wherein the structural element is selected from the group consisting of a shell, a collar, an oil flowline, a pipeline, a drilling riser, a production riser, a steel tubular, import and export risers, subsea pipelines, tendons for tension leg platforms, legs for traditional fixed and for compliant platforms, space-frame members for platforms, cables, umbilicals, mooring elements for deepwater platforms, hull structures for tension leg platforms and for spar type structures, and column structures for tension leg platforms and for spar type structures.  
   
   
       11 . The method of  claim 9 , wherein the structural element comprises a plurality of sections welded to each other.  
   
   
       12 . The method of  claim 9 , wherein the structural element comprises a plurality of sections threaded to each other.  
   
   
       13 . The method of  claim 9 , wherein attaching at least one helical strake about the structural element comprises attaching at least three helical strakes about the structural element.  
   
   
       14 . The method of  claim 9 , wherein the at least one ramp comprises a plurality of ramps aligned along a longitudinal axis of the structural element, where the roller interfaces with the structural element.  
   
   
       15 . The method of  claim 9 , wherein the at least one ramp comprises a first set of ramps and a second set of ramps, the first set and the second set aligned along a longitudinal axis of the structural element, the first set adapted to interface with a first roller, and the second set adapted to interface with a second roller azimuthally spaced apart from the first roller.  
   
   
       16 . The method of  claim 9 , wherein the first roller is azimuthally spaced apart from the second roller by 90 to 150 degrees measured as an arc angle of the structural element.