Riser Clamp With Composite Lining For Offshore Friction
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Solution Overview
Problem
Existing riser clamps made of steel fail to withstand alternating high pressures, leading to buckling and torsional forces, causing permanent deformation and compromising the corrosion protective layer on the riser, which results in reduced friction and potential seawater ingress.
Innovation Solution
A riser clamp with an internal abutment surface made of fibre reinforced composite material, designed to bear against the external surface of the riser, and tensioned using circumferentially acting tightening means, such as tensioning bands with shackles and screws, to enhance frictional engagement and prevent rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If steel riser clamps are used, then structural strength is provided, but friction with the riser surface is insufficient and rotation occurs
Solution Approach 1:
The clamp incorporates a composite material lining on its internal abutment surface that combines high friction properties with structural integrity. This lining layer is bonded to the steel clamp body, providing enhanced frictional engagement with the riser surface while the steel substrate maintains the required structural strength.
Solution Approach 2:
The friction-enhancing lining is applied locally to the internal abutment surface of the clamp that contacts the riser, rather than making the entire clamp structure composite. This localized application optimizes friction where needed while maintaining the structural advantages of steel in load-bearing areas.
2Strength
If steel riser clamps are used, then structural strength is provided, but permanent deformation occurs under alternating high pressure
Solution Approach 1:
The composite lining material is selected to have superior resistance to deformation under cyclic loading compared to steel. This lining layer absorbs and distributes the alternating pressure forces, preventing the permanent deformation and pointwise stress concentrations that occur with homogeneous steel clamps.
Solution Approach 2:
The invention changes the material parameters of the clamp's contact surface by introducing a composite lining with different mechanical properties (higher elasticity, lower density, superior fatigue resistance) compared to steel, thereby improving performance under alternating high pressure conditions.
3Reliability
If the riser clamp rotates, then friction is lost, but the corrosion protective layer is compromised
Solution Approach 1:
The high-friction lining is applied in advance to the clamp's internal surface to prevent rotation from occurring in the first place. By ensuring sufficient frictional engagement through the optimized lining material, the design proactively prevents the harmful action of rotation that would compromise the corrosion protective layer.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The fibre reinforced composite material provides increased friction and resistance to buckling and torsional forces, maintaining the integrity of the corrosion protective layer and ensuring secure fixation of the riser clamp, even under high pressure conditions.
Implementation Method 1
the beneficial friction properties obtained partly is due to the E-module of the armoured or reinforced composite material which is in the order of magnitude 10 GPa (GigaPascal)
Data Source
AI summary
A riser clamp (1) made up of several parts and designed to carry a plurality of fluid pipes (11) in parallel with and spaced apart from a surface coated steel riser (10) is shown. The riser (10) itself is designed to be deployed into the sea for communication between a well head at the seabed and a surface vessel. Each riser clamp (1) is designed for frictional, non rotatable fixation to the surface coated riser (10) and is provided with a plurality of pipe saddles (V) to carry the respective fluid pipes (11). The riser clamp (1) has an internal abutment surface (2) made of fiber reinforced composite material which is configured substantially complementary to and designed to bear against the external, surface coated surface of the riser (10). The riser clamp (1) is tightened by means of circumferentially acting tightening means.