Long Fiber Thermoplastic Stop Collars for Buoyancy Module Retention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The weight of landing strings in offshore drilling limits the overall drilling depth due to the weight carried by the drilling rig, necessitating a solution that reduces the weight while maintaining structural integrity and safety, especially in olefin-based drilling mud environments with varying temperatures and pressures.
Innovation Solution
The implementation of buoyancy modules with stop collars formed from long fiber thermoplastic, secured by composite bolts and nuts, which are designed to withstand axial and lateral loads, and tested for mechanical properties under extreme conditions, ensuring the buoyancy modules remain in place and functional.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If heavy wall drill pipe is used to ensure sufficient tensile strength and structural integrity, then the strength and reliability are improved, but the weight of the landing string increases, limiting drilling depth capabilities
Solution Approach 1:
Buoyancy modules are attached to the landing string to provide an upward buoyant force that counteracts the weight of the drill pipe and equipment. This reduces the effective weight carried by the drilling rig, allowing greater drilling depth without compromising the structural integrity of the heavy wall drill pipe
Solution Approach 2:
The buoyancy modules use composite materials (such as foam core with protective outer layers) that provide high buoyancy-to-weight ratio. The stop collars and hardware use long fiber thermoplastic composites that offer high strength-to-weight ratio, reducing the overall weight while maintaining the necessary mechanical strength
2Length of moving object
If buoyancy modules are added to reduce landing string weight, then drilling depth capability is improved, but the reliability of the system may be compromised due to potential slippage or detachment under extreme temperatures and pressures
Solution Approach 1:
Stop collars are installed at the ends of buoyancy modules to prevent axial slippage and detachment. These stop collars create mechanical stops that cushion against the effects of extreme temperatures and pressures, ensuring the buoyancy modules remain securely positioned on the drill pipe throughout the drilling operation
Solution Approach 2:
The stop collars and hardware are made from long fiber thermoplastic composite materials that maintain their mechanical properties across a wide range of temperatures and pressures. This ensures the fastening system remains reliable under the extreme conditions encountered during offshore drilling operations
3Strength
If long fiber thermoplastic composite materials are used for stop collars and hardware, then the strength-to-weight ratio is improved and slippage is prevented, but the manufacturing complexity increases due to specialized molding processes
Solution Approach 1:
Long fiber thermoplastic composite materials are used to manufacture stop collars and hardware components. These materials provide exceptional strength-to-weight ratios and can be formed into complex shapes using extrusion-compression molding or injection molding processes, achieving both high performance and manufacturability
Solution Approach 2:
The manufacturing process utilizes temperature and pressure parameters to transform the composite material from a moldable state to a rigid finished component. By controlling these parameters during extrusion-compression molding or injection molding, complex geometric shapes with high strength properties are achieved efficiently
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
This solution effectively reduces the weight of the landing string, increasing drilling depth capabilities without compromising safety, as the stop collars and hardware maintain functionality under maximum operating pressures and temperatures, preventing slippage and ensuring the buoyancy modules remain secure.
Implementation Method 1
buoyancy modules with stop collars formed from long fiber thermoplastic
Data Source
AI summary
Fastening devices are described. In one example, the fastening devices can be used for a landing string buoyancy solution. The landing string hardware includes a stop collar to be fitted and secured around a drill pipe and stop collar hardware to secure the stop collar together around the drill pipe. The stop collar can be secured at one end of a number of buoyancy modules placed along a longitudinal length of the drill pipe to hold them into place along the drill pipe. The stop collar can be formed from long fiber thermoplastic using extrusion-compression molding. The stop collar hardware includes a bolt having an external thread formed from long fiber thermoplastic and a nut having an internal thread formed from long fiber thermoplastic. Both the stop collar and the stop collar hardware are tested for suitability for the application of holding the buoyancy modules in place under operating conditions.