Protective Ring Coupling Assembly for Corrosion-Stable Tubular Threads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing coupling assemblies for tubulars in oil and gas wells face challenges in protecting the interior and threaded ends from corrosion, especially when subjected to corrosive and erosive fluids, and are prone to damage due to temperature changes and mechanical stress, which can lead to increased corrosion and dimensional alterations.
Innovation Solution
A coupling assembly with a protective ring featuring a tongue and groove design that creates a tortuous path for fluids, reducing direct contact with the tubulars' metal surfaces and using a resilient corrosion barrier to maintain the ring's position without relying on compressive forces, ensuring effective fluid pressure equalization and resistance to temperature-induced movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protective ring is positioned in a coupling to protect from corrosion, then corrosion resistance is improved, but the protective ring is prone to damage from temperature changes and mechanical stress
Solution Approach 1:
The patent applies parameter changes by utilizing the thermal expansion and contraction properties of materials in response to temperature changes. The coupling assembly is designed to accommodate dimensional alterations through controlled parameter changes, allowing the protective ring and tubulars to expand and contract with temperature fluctuations without causing damage or compromising corrosion protection.
2Ease of operation
If the protective ring relies on compressive forces to maintain position, then positioning is simple, but the ring is vulnerable to damage under mechanical stress and temperature changes
Solution Approach 1:
The patent applies dynamics by enabling the protective ring to move axially within the coupling in response to temperature-induced dimensional changes. This dynamic positioning allows the ring to maintain its protective function despite thermal expansion and contraction, preventing damage while preserving corrosion resistance without requiring complex positioning mechanisms.
3Reliability
If tubulars are made from chromium alloy to resist corrosion, then corrosion resistance is improved, but the cost increases significantly
Solution Approach 1:
The patent applies local quality by providing corrosion protection only where it is most critical - at the threaded ends and interior surfaces of the coupling assembly. The protective ring and lined tubulars apply corrosion-resistant lining selectively to areas exposed to corrosive fluids, rather than requiring the entire tubular to be made from expensive chromium alloy, thus reducing material costs while maintaining effective corrosion resistance.
4Reliability
If coatings are applied to drill pipe to prevent corrosion, then corrosion resistance is improved, but the coatings are prone to chipping and scratching
Solution Approach 1:
The patent applies the nested doll principle by placing the protective ring inside the coupling assembly, nesting it within the existing structure. This internal positioning protects the corrosion-resistant lining from external mechanical damage such as chipping and scratching that would occur if coatings were applied to the outer surfaces of drill pipe, while still providing effective corrosion protection where needed.
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 solution significantly reduces corrosion risk by minimizing fluid contact with metal surfaces and maintaining the protective ring's position effectively, even under temperature changes and mechanical stress, thereby extending the lifespan of the coupling assembly.
Implementation Method 1
A coupling assembly with a protective ring featuring a tongue and groove design that creates a tortuous path for fluids, reducing direct contact with the tubulars' metal surfaces and using a resilient corrosion barrier to maintain the ring's position without relying on compressive forces
Implementation Method 2
using a resilient corrosion barrier to maintain the ring's position without relying on compressive forces, ensuring effective fluid pressure equalization
Data Source
AI summary
A coupling assembly includes a coupling, a protective ring and two tubulars, the coupling of generally cylindrical shape with a channel therethrough, the coupling having at least one internal thread and two coupling ends and a pin end of at least one of the two tubulars having an external thread for threaded mating therewith so that the coupling assembly provides a connection between the two tubulars, the protective ring including a ring body for positioning adjacent an interior wall of the coupling between the two ends thereof, the ring body being generally cylindrical and having a ring channel therethrough, the protective ring includes one of a tongue and groove and at least one of the ends of at least one of the two tubulars having the other of a tongue and groove.