Hydraulic Plug Valve Sealing Under High Fracturing Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High pressure valves relying solely on metal-to-metal sealing mechanisms are unreliable due to changing tolerances and environmental influences, and are prone to failure when exposed to upstream forces, sand, and chemicals.
Innovation Solution
A high pressure valve system with upstream and downstream assemblies preloaded with hydraulic fluid, creating dynamic forces on a plug via interconnected pistons and springs, which apply self-sustaining clamping forces to enhance sealing reliability and reduce variance, utilizing frac energy to increase hydraulic pressure for improved performance during fracturing operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a metal-to-metal sealing mechanism is used in high pressure valves, then the valve can operate at high pressures, but the reliability decreases due to changing tolerances and environmental influences
Solution Approach 1:
The patent introduces a fluid intermediary (hydraulic fluid) between the barrier and the sealing surfaces, replacing direct metal-to-metal contact. This fluid intermediary transmits force while accommodating tolerance variations and environmental influences, thereby maintaining sealing reliability under high pressure conditions without the drawbacks of direct metal contact
Solution Approach 2:
The patent employs hydraulic principles by using incompressible fluid in a closed chamber to transmit and amplify force onto the barrier. The hydraulic system provides consistent force application that compensates for tolerance changes and environmental factors, ensuring reliable sealing at high pressures while eliminating the need for precise metal-to-metal alignment
2Object-affected harmful factors
If a floating barrier design is used, then the valve body is protected from direct exposure to sand and chemicals, but the barrier may move under upstream forces exposing the valve body to contaminants
Solution Approach 1:
The patent replaces the purely mechanical floating barrier system with a hybrid hydraulic-mechanical system. The hydraulic fluid provides continuous force to maintain the barrier in the correct position, preventing movement that would expose the valve body to contaminants while still allowing the barrier to float for protection. The incompressible fluid ensures consistent positioning under varying upstream forces
3Reliability
If hydraulic fluid is pre-loaded in chambers, then dynamic clamping force is created to improve sealing, but the system complexity increases
Solution Approach 1:
The patent merges the sealing mechanism and the positioning mechanism into a single integrated hydraulic system. The same incompressible fluid that provides sealing force also provides positioning force, eliminating the need for separate systems. This integration reduces overall system complexity while maintaining high sealing reliability through the unified hydraulic approach
Solution Approach 2:
The hydraulic fluid system performs multiple functions simultaneously: it provides sealing force, positioning force, and force amplification through the piston mechanism. This multi-functionality reduces the number of separate components needed, thereby reducing system complexity while achieving reliable sealing under high pressure conditions
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 provides increased reliability and reduced risk of failure by applying consistent clamping forces, minimizing human interaction during fracturing, and reducing the need for part replacement, while maintaining valve performance and safety.
Implementation Method 1
The upstream chamber and the downstream chambers may be dependent pistons that are configured to create dynamic forces acting upon the plug. The upstream chamber and the downstream chamber, housing the corresponding springs, may be pre-loaded with hydraulic fluid at a first PSI and a second PSI, respectively.
Implementation Method 2
The plug may be configured to contact both the upstream seat and the downstream seat based on the upstream spring creating first forces on the upstream seat and the downstream spring creating second forces on the downstream seat.
Implementation Method 3
When the downstream seat moves in the first direction, the spring may compress decreasing the size of the downstream chamber. This may cause hydraulic fluid in the downstream chamber to circulate to the upstream chamber via the communication port.
Implementation Method 4
The energy system may utilize the frac PSI pulled upstream from the high pressure valve within the casing, wherein the frac energy may be utilized during a fracing operation and is external to the pre-loaded PSI associated with the hydraulic fluid within the chambers. The energy system may convert the frac energy to hydraulic PSI within the chambers to increase the PSI associated with the upstream and/or downstream assembly.
Data Source
AI summary
A plug that contacts both an upstream seat and a downstream seat based on a upstream spring creating first forces on the upstream seat and a downstream spring creating second forces on the downstream seat. The first forces may be in a downstream direction and the second forces may be in an upstream direction. Additionally, the upstream chamber and the downstream chambers may be dependent pistons that are configured to create dynamic forces acting upon the plug.