Downhole Safety Valve With Nested Secondary Wireline Insert
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Solution Overview
Problem
Current downhole safety valve systems in the drilling and completion industry face challenges with malfunction due to material buildup, requiring time-consuming and costly replacement procedures, especially in extreme conditions, where existing solutions are not robust enough to handle varying pressures and maintain reliable operation.
Innovation Solution
The design incorporates a safety valve system with enhanced seal bores and a hydraulic control chamber configuration that allows for the accommodation of a wireline insert safety valve, enabling improved sealing and operation under high control pressures, reducing the need for frequent replacements and enhancing system reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional safety valve is used in downhole applications, then the valve can prevent fluid flow through the tubing string, but the valve becomes inoperable due to material buildup such as paraffin and fines on the components
Solution Approach 1:
The safety valve is divided into two separate valves: a primary safety valve and a secondary safety valve. Each valve has its own blocking member and seal bores. This segmentation allows the secondary valve to serve as a backup when the primary valve becomes inoperable due to material buildup, thereby maintaining reliability without requiring complete valve replacement
Solution Approach 2:
The secondary safety valve is pre-installed within the housing of the primary safety valve during manufacturing. This preliminary action ensures that when material buildup renders the primary valve inoperable, the secondary valve is already in position and can be activated immediately through the existing control fluid line, avoiding the need for time-consuming retrieval and replacement operations
2Reliability
If the safety valve assembly is retrieved to surface for replacement, then the inoperable valve can be replaced with a new assembly, but the procedure requires significant time and expense
Solution Approach 1:
The secondary safety valve is nested within the housing of the primary safety valve. The secondary valve's outer diameter is configured to fit within the inner diameter of the primary valve assembly. This nesting arrangement allows the secondary valve to remain accessible and operable even when the primary valve is in place, enabling in-situ replacement without retrieving the entire assembly to surface
Solution Approach 2:
The system enables self-service replacement where the secondary valve can be activated to replace the primary valve's function without requiring external intervention or retrieval to surface. The control fluid line that serves the primary valve also serves the secondary valve, allowing the system to service itself by switching between valves
3Ease of operation
If a wireline insertable safety valve is used, then the valve can be inserted downhole via wireline, but additional operations are required to lock the valve in open position and establish fluid communication
Solution Approach 1:
The control fluid line is designed to serve dual purposes: it controls both the primary safety valve and the secondary safety valve. The same hydraulic connection that actuates the primary valve also actuates the secondary valve, eliminating the need for separate control systems and reducing overall device complexity despite having two valves
Solution Approach 2:
The seal bores of the primary and secondary valves are merged into a common sealing system within the housing. The sealing surfaces and control mechanisms are combined such that one control fluid line can effectively manage both valves, reducing the number of separate operations needed compared to having entirely separate valve systems
4Stress or pressure
If the existing system operates under extreme conditions, then the valve can handle high pressures, but the system is not robust enough to handle varying pressures and maintain reliable operation
Solution Approach 1:
The system allows for changes in operational parameters by switching between the primary and secondary valves. Each valve can be optimized for different pressure ranges or operational conditions. When pressure conditions vary or one valve becomes inoperable, the system can transition to the other valve, maintaining reliable operation across a broader range of pressure parameters
Solution Approach 2:
The secondary safety valve serves as a pre-prepared backup that cushions against the risk of primary valve failure under extreme or varying pressure conditions. This prior cushioning ensures that if the primary valve cannot handle certain pressure variations or becomes inoperable, the secondary valve is already in position to maintain system 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
This configuration enables more robust operation of downhole safety valves, reducing the frequency of replacements and improving system reliability by accommodating higher control pressures, thus addressing the limitations of existing systems in extreme conditions.
Implementation Method 1
a hydraulic control chamber within a wall of the at least one tubular housing... when sufficient control fluid (e.g. hydraulic fluid) pressure is supplied from surface, the rod piston moves downwardly in the chamber, thus forcing the flow tube downwardly through the flapper to open the valve
Implementation Method 2
A torsion spring is provided to bias the flapper in the closed position to prevent fluid flow through the tubing string
Data Source
AI summary
A safety valve including at least one tubular housing having an interior surface. A flow path provided within an interior of the at least one tubular housing. A movable flow path blocking member arranged to block the flow path in a closed condition of the blocking member and open the flow path in an open condition of the blocking member. A first seal bore on the interior surface of the at least one tubular housing. A hydraulic control chamber within a wall of the at least one tubular housing; and, a second seal bore on the interior surface of the at least one tubular housing; wherein the hydraulic control chamber is disposed longitudinally between the first and second seal bores. The second seal bore is disposed longitudinally between the hydraulic control chamber and the movable flow path blocking member. Also included is a method of accommodating a high control pressure wireline insert safety valve within a tubing retrievable safety valve.