Downhole Safety Valve Dynamic Sealing for Rod Wear
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Solution Overview
Problem
Conventional downhole safety valves for sucker rod pumps in the oil and gas industry face issues with tortuous flow paths leading to clogging and suboptimal hydrocarbon flow rates, as well as excessive wear and maintenance due to constant contact with the sucker rod.
Innovation Solution
A downhole safety valve with a sealing system comprising reversible elastic elements that move between open and closed positions, minimizing contact with the sucker rod during operation and utilizing a conical section to enhance sealing and prevent debris obstruction, ensuring self-sealing capabilities even in case of actuation failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing system is always engaged on the sucker rod, then sealing reliability is improved, but the flow path becomes restricted and wear increases
Solution Approach 1:
The sealing system is designed to be dynamic rather than static. The seal elements are retractable and can move between an engaged position (when rod is stationary) and a disengaged position (when rod is moving), allowing the system to adapt its sealing function based on operational conditions without restricting flow during production
Solution Approach 2:
The sealing system operates periodically, engaging with the sucker rod only during specific phases of the reciprocating motion cycle. During the productive flow phase, the seal is disengaged to maximize hydrocarbon flow rate, and engages only when needed for sealing, creating a periodic action that balances reliability with productivity
2Reliability
If a sealing system is always engaged on the sucker rod, then sealing is maintained, but maintenance frequency increases due to excessive wear
Solution Approach 1:
The dynamic sealing system minimizes contact time between the seal elements and the sucker rod by engaging only when necessary. This reduced contact duration significantly decreases wear accumulation, extending the maintenance interval and improving ease of repair without compromising sealing function when engaged
3Reliability
If a tortuous flow path is used for sealing, then sealing capability is improved, but the valve becomes prone to clogging with debris or paraffin
Solution Approach 1:
The harmful tortuous flow path configuration is extracted and removed from the design. Instead, a streamlined, direct flow path is implemented that maintains sealing capability through proper seal geometry and positioning while eliminating the tortuous sections where debris and paraffin would accumulate and cause clogging
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 improves flow path efficiency, reduces maintenance, and provides effective sealing without limiting the sucker rod's stroke, maintaining optimal hydrocarbon extraction and ensuring reliable operation under varying pressures.
Implementation Method 1
a sealing system, which includes a plurality of elastic and reversible elements arranged to surround said rod
Data Source
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AI summary
The present invention relates to the extraction systems in the oil sector, in particular to the equipment intended for the completion of the wells after their drilling; more in particular, the present invention relates to a safety valve for artificial lifting wells driven by reciprocating downhole rod pumps.