Insulated Drill Pipe Coupling for Downhole Heat Isolation
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Solution Overview
Problem
Existing insulated drill pipes fail to prevent overheating of drilling fluid due to indirect heat exchange with geothermal wells, leading to potential malfunction of downhole telemetry and premature drill string failure, especially under high subsea pressures.
Innovation Solution
The insulated drill pipes feature an outer drill pipe with an inner tubing secured by a coupling system, an annulus filled with insulating material, and a coupling system that includes couplers with specific thread designs to maintain structural integrity and prevent heat transfer, allowing drilling fluid to pass without overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermoplastic insulation is applied by hot wrapping or spray gun, then insulation coverage is achieved, but water cannot pass between the pipe and insulation, causing water pockets to form under high subsea pressure
Solution Approach 1:
The patent uses a flexible membrane or thin film layer between the drill pipe and insulation that allows water to pass through while maintaining insulation integrity. This flexible barrier prevents water pocket formation under pressure while preserving the insulating function.
Solution Approach 2:
The patent introduces an intermediary layer (membrane or thin film) between the drill pipe and insulation that mediates water flow. This intermediary allows water to pass through to prevent pocket formation while maintaining the insulating barrier's effectiveness.
2Temperature
If insulation is applied to prevent heat transfer, then heat protection is improved, but the insulation structure becomes complex with multiple layers and components
Solution Approach 1:
The patent combines multiple functions into a single integrated insulation structure that includes the insulating material, water barrier membrane, and structural support elements as a unified assembly, reducing overall complexity while maintaining temperature control effectiveness.
Solution Approach 2:
The insulation structure is designed with multi-functionality, where a single component or layer performs multiple functions (thermal insulation, water barrier, structural support), thereby reducing the number of separate components needed and simplifying the overall structure.
3Reliability
If the drill pipe riser is raised to the surface with water under pressure in pockets, then water bursts through the insulation causing embolism, but preventing water entry requires blocking water flow
Solution Approach 1:
The flexible membrane or thin film layer allows water to pass through progressively, preventing pressure buildup that would cause bursting. This flexible barrier maintains insulation integrity while eliminating the water burst embolism problem by allowing controlled water flow.
Solution Approach 2:
The patent applies preliminary anti-action by providing a water-permeable barrier before water can accumulate under pressure. This preventive measure stops water pocket formation before it can lead to bursting and embolism, addressing the problem in advance rather than reactively.
4Stability of the object's composition
If inner tubing is secured rigidly to outer drill pipe, then structural stability is improved, but the drill string cannot be disassembled for servicing or insulation replacement
Solution Approach 1:
The patent segments the coupling system into separable components (couplers, threaded connections, or bayonet connectors) that allow the inner tubing to be securely attached during operation but easily disconnected for servicing. This segmentation maintains structural stability during use while enabling repair and maintenance.
Solution Approach 2:
The coupling mechanism transitions from a static rigid connection to a dynamic system that can be easily assembled and disassembled. The coupling system provides stable connection during drilling operations but allows quick separation for maintenance, adapting to different operational states.
5Strength
If the inner tube has high tensile strength to match the outer drill pipe, then structural integrity at depth is maintained, but the overall weight of the drill string increases
Solution Approach 1:
The patent applies local quality by providing high tensile strength specifically where needed (in the inner tube and coupling system) while allowing other components to have optimized weight. This localized strengthening maintains structural integrity at depth without requiring the entire drill string to be uniformly heavy.
Solution Approach 2:
The patent uses composite materials or material combinations that provide high tensile strength-to-weight ratio. The inner tube and coupling components are made from materials that offer superior strength relative to their weight, maintaining structural integrity while minimizing overall drill string weight.
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 effectively reduces heat transfer to the drilling fluid, maintains structural integrity at deep depths, and extends the life expectancy of the drill string by enabling disassembly and servicing of individual sections.
Implementation Method 1
an insulative material positioned in the annulus between the outer drill pipe and the inner tubing
Data Source
AI summary
Insulated drill pipes, couplers and coupling systems for securing an inner (liner) tubing inside of an outer drill pipe, with insulation in between, thread designs for the inner liner tubing, couplers, and outer drill pipe, and methods for assembling insulated drill pipes are described.