Device for arresting the propagation of a buckle in a double-walled pipe
AssigneeCoflexip
InventorsAntoine Bastard, Gordon Tough
Life of this patent
Estimating the term…
Abstract
Device for arresting the propagation of a buckle in a double walled pipe. The device comprising an outer pipe wall having a defined external diameter and placed around an inner pipe wall, defining an annular space between the said outer and inner walls; providing predetermined regions in the annular space which are bounded between two sealing blocks with radially opposed faces which are in contact with the outer and inner pipes; placing a curable compound in each region and curing it the length of each region is at least equal to 0.5 times the external diameter of the outer wall.
Claims23
The method of claim 22, further comprising the step of winding the pipe on a reel after placing and curing the compound.
The method of claim 22, wherein the axial length of the annular region is in the range of 0.5 to 2 times the external diameter of the carrier pipe.
The method of claim 22, wherein each of the sealing blocks is comprised of a material which is radially deformable when compressed axially and further including the step of axially compressing the sealing blocks to conform the radially outer margins thereof to the shape of the respective inner and outer walls of the carrier pipe and the flow pipe.
The method of claim 22, wherein the curable compound is an epoxy resin.
The method of claim 22, further including the steps of:
- providing an injection orifice through the wall of the carrier pipe into the annular region;
- and
- injecting the curable compound into the annular region through the orifice.
The method of claim 22, further comprising the steps of:
- reeling the rigid pipe onto a reel after assembly but before placing the curable compound in the annular region;
- unreeling the rigid pipe from the reel,
- placing the curable compound the annular region after the pipe has been unreeled, and
- heating the annular region to accelerate the curing of the curable compound.
The method of claim 22, wherein the curable compound has a pot life in the range of a few minutes to a few weeks.
The method of claim 22, further comprising the steps of:
- winding the pipe onto a receiving reel after placing the curable compound in the annular region;
- transporting the reel carrying the pipe to a site for use of the pipe, and
- unwinding the wound pipe from the reel at the site for use.
A method of manufacturing a reelable double-walled rigid pipe for underwater transportation of fluids, wherein the pipe comprises an inner flow pipe, the interior of which defines a passage for transporting the fluid, an outer carrier pipe which surrounds the flow pipe, and a plurality of longitudinally spaced separating elements between the inner and outer pipes which define an annular space therebetween, which is capable of arresting longitudinal propagation of buckling of the outer carrier pipe, the method comprising:
- selecting dimensions and properties of the inner pipe and the carrier pipe according to an intended fluid transportation application, and an intended pipeline location, and to have suitable mechanical properties which permit the double walled pipe to be plastically deformed for reeling on a vessel reel and then straightened while being laid offshore;
- assembling a double walled pipe using the selected carrier and flow pipes, and the separating elements, and also including at least one pair of sealing blocks axially spaced apart between the outer wall of the flow pipe and the inner wall of the carrier pipe;
- the sealing blocks having radially opposite faces and being dimensioned to be in contact respectively with the outer and inner walls of the flow pipe and the carrier pipe, to define a sealed annular region within the annular space;
- spacing the sealing blocks so that the axial length of the annular region is at least equal to 0.5 times the external diameter of the carrier pipe;
- placing a curable compound in the annular region;
- and curing the compound in the annular region.
Dependencies are inferred from the claim text.