Pipe Coupling With Interlocking Overhangs For Radial Sealing
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Solution Overview
Problem
Existing coupling systems for tubulars in well bores, such as screw-threaded connections, face issues with reliability in sealing, axial load bearing capacity, and complex supply chains, and are prone to make-up problems and fluid leakage.
Innovation Solution
A non-threaded coupling system utilizing profiled sections with oppositely directed overhangs that interlock when a radial force is applied, creating a metal-to-metal seal and providing axial load bearing capacity without the need for rotation or complex assembly processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If screw threaded connections are used to join tubulars, then the tubulars can be connected together, but the connection may come apart if the tubular string becomes stuck and cannot be rotated counter to the direction of the screw thread
Solution Approach 1:
The patent replaces the screw threaded mechanical connection system with a radially applied force system. Instead of using rotational mechanics to create and maintain the connection, the invention uses radial compression force to press the profiled sections together, eliminating the need for rotation and the associated reliability issues with stuck strings.
Solution Approach 2:
The patent inverts the conventional approach by applying force radially inward rather than using rotational torque. The profiled sections are designed to be pressed together radially, creating a secure connection through radial compression rather than through rotational threading, which resolves the problem of connections coming apart when rotation is prevented.
2Reliability
If screw threaded connections are used, then tubulars can be joined, but a fluid path can exist along the helical screw thread preventing reliable sealing
Solution Approach 1:
The patent replaces the helical threaded mechanical interface with a radial compression system using profiled sections. This substitution eliminates the helical path that creates fluid leakage channels, replacing it with a direct radial pressing action that creates a reliable metal-to-metal seal without complex threading geometry.
Solution Approach 2:
The patent extracts and removes the threaded portion from the connection system, eliminating the source of fluid path problems. By using profiled sections that are pressed together radially without threads, the invention removes the helical geometry that creates leakage paths while maintaining the essential function of joining tubulars.
3Strength
If standard profiled sections are used with radial force application, then connection is formed, but the profiles are subject to similar collapse and burst ratings as screw threaded connections because force acts on each coupling in an identical manner
Solution Approach 1:
The patent introduces asymmetry into the profiled sections by providing overhangs that are not symmetrically distributed. This asymmetric geometry causes the applied radial force to be distributed differently across the coupling, with some portions bearing more load than others, thereby increasing the overall collapse and burst resistance beyond what symmetric profiles could achieve.
Solution Approach 2:
The patent applies local quality by creating specific geometric features (overhangs) at particular locations on the profiled sections. These localized asymmetric features concentrate and distribute forces in specific areas, enhancing the structural integrity and resistance to collapse and burst pressures at critical locations rather than distributing force uniformly.
4Ease of manufacture
If screw threaded connections are used, then tubulars can be connected, but the threads are prone to make up problems and require the use of dope (lubricant and sealant) and have a complex supply chain
Solution Approach 1:
The patent replaces the threaded mechanical system with a radial compression system using profiled sections. This substitution eliminates the need for complex threading operations, lubricants, and sealants, simplifying both the manufacturing process and the supply chain by removing multiple auxiliary components and steps.
Solution Approach 2:
The profiled sections with overhangs are designed to self-align and self-secure when radial force is applied. The asymmetric geometry provides inherent guidance and locking without requiring external lubricants, sealants, or complex assembly procedures, allowing the connection to make itself without additional materials or steps.
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 achieves improved axial load bearing capacity, increased burst and collapse ratings, and simplified assembly by forming a secure, leak-proof connection between tubulars without the need for rotation or monitoring of weights and torque.
Implementation Method 1
by application of a radially inward force creating a connection having a metal to metal seal between the tubular members at the profiled sections
Data Source
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AI summary
A coupling system between tubular members such as tubing, pipes, casing and liner for location in a well bore in which the ends of each tubular have cooperating profiled sections. The profiled sections are arranged coaxially and a radially applied force is applied to form a metal to metal sealed connection. At least one profiled section includes a projection, the projection containing an overhang to the surface of the tubular member, the overhang locking with the opposing profile when the force is applied to provide a coupling with increased burst and collapse rating. Embodiments are provided of arrangements of overhangs such as oppositely directed overhangs and interlocking overhangs.