Pressure-Biased Valve Assembly for Stable Downhole Injection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing injection devices for downhole fluid injection face challenges with hydrostatic fall-through, leading to vacuum creation and potential fluid boiling, which can result in adverse effects like solid deposition and viscosity changes due to increased temperatures and pressures, and require expensive precision components for sealing, making them prone to contamination and damage from pressure surges.
Innovation Solution
An injection device with a valve assembly featuring first and second valve members that are actuated by fluid pressure, with a limiting arrangement to control movement and maintain a positive pressure within the injection line, utilizing a piston arrangement and biasing mechanism to ensure sealing and prevent leakage, and optionally including a surge protector and filter arrangement to manage pressure fluctuations and contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large sealing area is used in the valve assembly, then sealing reliability is improved, but the device complexity and sensitivity are worsened
Solution Approach 1:
The valve assembly is segmented into two separate valve members (first and second valve members) that can be independently positioned and sealed. This segmentation allows each valve member to have optimized sealing surfaces, improving overall sealing reliability while maintaining manageable device complexity through modular design
Solution Approach 2:
The first valve member is positioned inside the second valve member, creating a nested configuration. This nesting arrangement allows both valve members to cooperate in sealing the flow path without requiring large individual sealing areas, thereby improving sealing reliability while reducing device complexity and increasing sensitivity to pressure changes
2Measurement precision
If the valve members are made sensitive to pressure changes, then flow control precision is improved, but the device becomes more vulnerable to pressure surge damage
Solution Approach 1:
The biasing arrangement (spring member) is pre-configured to provide cushioning force on the first valve member. This beforehand cushioning protects the sensitive valve members from pressure surge damage by absorbing shock loads, while still allowing the valve members to remain sensitive enough for precise flow control under normal operating conditions
Solution Approach 2:
The biasing arrangement acts as an intermediary between the pressure forces and the first valve member. It mediates the interaction by providing a controlled restoring force that protects the valve member from extreme pressure surges while allowing precise response to normal pressure variations for accurate flow control
3Volume of moving object
If the valve members are positioned close together for compact design, then the device size is reduced, but the sealing reliability is worsened
Solution Approach 1:
The first valve member is nested inside the second valve member, creating a compact concentric arrangement. This nested configuration maintains adequate sealing distance between the valve members while minimizing the overall device volume, thereby achieving both compact size and reliable sealing
Solution Approach 2:
The valve members are arranged in a concentric configuration along the central axis of the housing, utilizing radial space efficiently. This dimensional arrangement allows the valve members to be positioned close together radially while maintaining sufficient axial distance for effective sealing, achieving compact design without compromising sealing reliability
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 maintains a positive pressure within the injection line, minimizing the risk of vacuum creation and fluid boiling, reduces the need for large sealing areas, and enhances sensitivity and durability by using a smaller sealing area, while automatically adjusting to maintain pressure equilibrium and protect against surging flows.
Implementation Method 1
the first valve member is biased against the second member by inlet fluid pressure (Pi) to assist sealing therebetween
Implementation Method 2
the second valve member comprises or defines a piston arrangement configured to be actuated by fluid pressure to move said second valve
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
An injection device for use in injecting a fluid into a target location comprises a housing and a valve assembly located within the housing. The housing defines an inlet for communicating with an injection line, an outlet for communicating with a target location, and an injection fluid flow path extending between the inlet and outlet. The valve assembly located is configured to control the flow of injection fluid along the flow path and comprises first and second valve members both arranged to move within the housing, wherein in an open configuration to permit flow the first and second members are disengaged, and in a closed configuration to prevent flow the first and second members are engaged and the first valve member is biased against the second member by inlet fluid pressure to assist sealing therebetween.