Chemical Injection Valve Bypass Flow for Seal Erosion Control
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Solution Overview
Problem
Existing chemical injection valves in subterranean wells face challenges in maintaining consistent and predictable control over chemical treatment injection while minimizing seal erosion and excess chemical usage.
Innovation Solution
A chemical injection valve design featuring a valve stem with a resilient primary seal and a metal secondary seal, along with bypass passages that allow chemical treatment to flow without engaging the primary seal during open positions, reducing erosion and ensuring precise pressure control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the valve stem and seal are engaged during open position to control chemical injection, then precise pressure control is achieved, but seal erosion increases due to high pressure differential flow
Solution Approach 1:
The valve design separates the flow control function from the sealing function. The valve stem controls pressure by moving between closed and open positions, while the seal is protected from direct exposure to high-pressure chemical flow during the open position. This segmentation allows precise pressure control without subjecting the seal to erosive flow conditions.
Solution Approach 2:
The harmful factor (chemical flow) is extracted from the seal environment. When the valve is open, the chemical treatment flows through a dedicated flow path that bypasses the seal, eliminating direct contact between the erosive flow and the seal surface. This extraction protects the seal while maintaining flow control capability.
2Ease of operation
If the seal is exposed to high pressure differential flow during valve operation, then valve control function is maintained, but seal longevity decreases due to erosion damage
Solution Approach 1:
An intermediary flow path is introduced that allows chemical treatment to pass from the closed to open position without directly contacting the seal. This intermediary pathway mediates between the valve control requirement and seal protection, enabling full valve operation while shielding the seal from erosive flow conditions.
Solution Approach 2:
The valve design incorporates a protective arrangement where the seal is positioned to be biased against a shoulder, providing mechanical support and protection before flow conditions become erosive. This pre-positioning and structural support cushion the seal against potential erosion damage during valve transitions.
3Reliability
If excess chemical treatment is injected to ensure sufficient treatment, then treatment effectiveness is improved, but chemical waste increases
Solution Approach 1:
The valve design enables precise pressure control through the valve stem's movement between closed and open positions, allowing accurate dosing of chemical treatment. This feedback-controlled mechanism ensures that only the required amount of chemical is injected, preventing both under-treatment and excessive chemical usage, thereby improving treatment reliability while minimizing waste.
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 design enhances control over chemical treatment injection, reduces seal erosion, and maintains consistent operation by allowing bypass flow through the valve stem, ensuring efficient and predictable treatment delivery.
Implementation Method 1
a resilient primary seal that prevents flow through an annular gap between the valve stem and the housing when the valve is in the closed position
Implementation Method 2
When the valve stem is in the open position, the bypass passage is in communication with the first flow passage section and the second flow passage section, allowing chemical treatment to flow from the first flow passage section to the second flow passage section
Data Source
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AI summary
A chemical injection valve (12) can include a valve stem (40), flow between sections of a flow passage (38) being prevented and permitted in respective closed and open positions of the valve stem, a resilient primary seal (46) that prevents flow through an annular gap surrounding the valve stem in the closed position, and a bypass passage (60) in communication with the annular gap and a flow passage section, and in communication with another flow passage section in the open position. A chemical injection system can include a chemical treatment pumped through a chemical injection valve and into an interior of a tubular string (16), and the chemical injection valve including a valve stem and a bypass passage extending between a flow passage section and an annulus surrounding the valve stem, the annulus being positioned longitudinally between a resilient primary seal and a metal secondary seal (54).