Polyurethane Pipe Weight Coating for Fast-Cure Subsea Reeling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional weight coatings for subsea pipelines, such as those made of concrete, face challenges including long curing times, lack of flexibility, and environmental pH disruption, which hinder production efficiency and environmental sustainability.
Innovation Solution
A pipe weight coating system utilizing a two-component polyurethane binder composed of an isocyanate component and an isocyanate-reactive component, combined with an aggregate, which can cure and be shipped within 24 hours, offering improved flexibility and environmental neutrality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If concrete is used for weight coating, then the coating provides negative buoyancy, but it requires 28 days to cure before use
Solution Approach 1:
The patent changes the chemical composition and curing parameters of the weight coating material from conventional concrete to a chemically activated mixture containing calcium oxide, calcium sulfate, and water. This parameter change reduces the curing time from 28 days to approximately 24 hours while maintaining the negative buoyancy property through proper selection of aggregate and binder ratios.
Solution Approach 2:
The invention uses a composite material system combining multiple components: calcium oxide, calcium sulfate, water, and aggregate in specific proportions. This composite approach enables accelerated curing through chemical reactions between components while maintaining the density required for negative buoyancy, resolving the contradiction between rapid setting and reliable performance.
2Reliability
If concrete is used for weight coating, then the coating provides weighting function, but it lacks flexibility for reeling
Solution Approach 1:
The patent modifies the material parameters by using a chemically activated binder system that cures to a flexible state rather than rigid concrete. The controlled hydration and chemical reactions produce a coating that maintains flexibility for reeling operations while achieving sufficient strength for weighting function, eliminating the contradiction between structural integrity and adaptability.
3Reliability
If concrete is used for weight coating, then the coating provides negative buoyancy, but it increases pH of surrounding water
Solution Approach 1:
The patent converts the potentially harmful high pH characteristic of concrete into a beneficial controlled chemical activation process. The calcium oxide and calcium sulfate react with water to produce a mildly alkaline environment that accelerates curing while remaining environmentally acceptable. The chemical reactions that once caused harmful pH disruption are now controlled to achieve rapid setting without significant environmental impact.
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 system allows for faster production and installation of longer pipe lengths, reduces field work, and maintains environmental neutrality by curing quickly and not disrupting pH levels.
Implementation Method 1
mixing the isocyanate component and the isocyanate-reactive component to form the polyurethane binder
Data Source
AI summary
Provided herein are novel and improved weight coating systems suitable for use with pipes, particularly pipes that are submerged in liquid, such as water, in environments including oceans, seas, marshes, lakes and rivers. The novel coating systems provided herein comprise an aggregate and a polyurethane binder, wherein the polyurethane binder is a two-component composition comprising an isocyanate component and an iso-cyanate-reactive component. The coating systems provided have increased durability, as well as flexibility allowing for efficiencies related to transportation, storage, use and resistance to corrosive effects. Furthermore, the coating systems are cost effective and have minimal or zero impact on the environments in which they are utilized.