Downhole Regulator With Helical Coupling for Axial-Torsional Vibration
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Solution Overview
Problem
Existing downhole regulating devices with helical couplings and bi-directional biasing devices are inefficient in managing torsional and axial loads due to friction, non-linear spring curves, and complex tool designs, leading to reduced responsiveness and increased wear on motor components.
Innovation Solution
A downhole regulating device with a bi-directional biasing device that allows relative axial and rotational movement between portions, featuring a neutral position between fully extended and contracted positions, and incorporates a torsional spring laminate with carbon fiber layers to improve fatigue performance and reduce friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a counter spring is integrated with the helical coupling to extend the operating envelope, then the device can function at low weight, but the tool becomes relatively long, heavy, and complex
Solution Approach 1:
The patent combines the counter spring and biasing device into a single integrated bi-directional biasing device with a neutral position, eliminating the need for separate components while maintaining the extended operating envelope capability
Solution Approach 2:
The bi-directional biasing device performs multiple functions simultaneously: it acts as both a counter spring to balance pump-open force and a biasing device to maintain contact between the helical coupling and drilling string, replacing the need for separate components
2Adaptability or versatility
If a non-linear spring curve is used in the counter spring design, then the operating envelope is extended, but the sensitivity to changes in axial and torsional loads is reduced
Solution Approach 1:
The patent employs a linear spring curve design with a neutral position that maintains constant sensitivity to load changes across the operating range, while still achieving extended operating envelope through the bi-directional configuration
3Power
If a helical coupling with lead angle of 40 to 80 degrees is used, then the coupling can transmit torque, but friction in the coupling and bearings reduces responsiveness to small changes in torque or weight on bit
Solution Approach 1:
The patent optimizes the helical coupling lead angle to a range of 10 to 30 degrees, which reduces friction and improves responsiveness to small load changes while maintaining adequate torque transmission capability through the optimized neutral position configuration
4Adaptability or versatility
If the neutral position of the tool is placed between fully contracted and fully extended positions, then the operating envelope is extended, but the device requires a relatively long stroke length
Solution Approach 1:
The patent optimizes the stroke length and neutral position configuration to achieve extended operating envelope with minimized device length, using a compact bi-directional biasing device arrangement
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 device effectively mitigates axial and torsional vibrations, reducing wear on motor components and enhancing drilling efficiency by autonomously adjusting weight and torque on the bit, while maintaining responsiveness to small load changes.
Implementation Method 1
a bi-directional biasing device that resists movement between the lower portion and the upper portion in both axial extension and contraction directions
Implementation Method 2
a helical coupling between a lower portion and an upper portion of the downhole regulating device and structured to allow relative axial and rotational movement between the lower portion and the upper portion
Implementation Method 3
incorporates a torsional spring laminate with carbon fiber layers to improve fatigue performance and reduce friction
Data Source
AI summary
A downhole regulating device used in a downhole drill string between a drilling rig and a drill bit. The downhole regulating device has a helical coupling between the upper and lower portion to allow a relative axial and rotational movement defined by the lead of the helical coupling, between the upper and lower portions; a bi-directional biasing device that resists movement in both extension and contraction from the neutral position depending on the combination of pumping pressure, torque, axial hanging loads from drill string components below the tool and applied weight on bit. The biasing device is designed such that there is no pre-load required. A secondary one-directional element may be part of the biasing device to modify the spring rate or stroke length in contraction direction. A metal and composite laminated torsion spring is also described.