Subsurface Safety Valve Additive Injection Mechanism
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Solution Overview
Problem
Existing surface-controlled subsurface safety valves (SCSSVs) face challenges in efficiently managing additive injection during well operations, particularly at the end of a well's life, with issues such as valve closure upon additive injection cessation and potential effluent leakage, especially under severe conditions.
Innovation Solution
A safety valve design featuring a movable safety plug within a connection duct, driven by the production tube's axial movement, allowing additive injection when the valve is open and preventing it when closed, ensuring safe operation even under severe conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If additive injection is performed through the control line during well operations, then the well can be maintained in production at the end of its life, but the valve may close unintentionally when additive injection ceases, causing operational disruption
Solution Approach 1:
The system is divided into separate functional components: the control line for hydraulic pressure, the additive injection line for chemical injection, and the safety valve for flow control. This segmentation allows independent operation of each function, preventing the valve from closing when additive injection stops, as the control line remains independent and maintains hydraulic pressure separately.
Solution Approach 2:
A dedicated additive injection line acts as an intermediary between the surface injection system and the wellbore, separate from the control line. This intermediary pathway allows additive injection without interfering with the hydraulic control system, eliminating the risk of valve closure due to injection cessation.
2Adaptability or versatility
If the safety valve allows additive injection during severe well conditions, then operational flexibility is improved, but effluent leakage may occur leading to catastrophic spills
Solution Approach 1:
The safety valve incorporates dynamic positioning capability, allowing it to be placed in intermediate positions between fully open and fully closed states. This enables the valve to maintain controlled flow during additive injection while preventing effluent leakage, adapting its opening degree based on operational requirements and well conditions.
Solution Approach 2:
The valve controls flow by changing its opening parameter dynamically. During additive injection, the valve maintains a controlled opening degree that permits additive flow while preventing effluent escape. The opening parameter is adjusted based on injection rate and well conditions, ensuring safety while maintaining operational flexibility.
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 effectively regulates additive flow and prevents unwanted effluent rise, enhancing safety and reducing the risk of catastrophic leaks, such as oil spills, during both normal and abnormal operational conditions.
Implementation Method 1
the production tube being arranged to push the safety plug in said axial direction on passing from its retracted position towards its advanced position, the driving connection between the production tube and the safety plug being a mechanical connection by contact
Implementation Method 2
a safety plug being provided in the connection duct and being movable in translation along the axial direction in which the production tube moves in order to close or open the connection duct
Data Source
AI summary
A safety valve for an effluent-production installation, the safety valve comprising a longitudinal shell in which there extends a production tube defining an inside volume for effluent flow. The tube is movable in translation inside the shell in an axial direction between an advanced position in which effluent flow is authorized from the bottom of the installation towards the surface, and a retracted position in which effluent flow is prevented. The valve includes a connection duct between a feed line for feeding at least one additive from the surface and an injection line for injecting the additive downhole, a safety plug being provided in the connection duct in order to close or open the duct depending on whether the production tube is in its retracted position or its advanced position.