Partially Retrievable Safety Valve Actuator System
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Solution Overview
Problem
Deep-set safety valves in subterranean wells face challenges with high hydraulic pressures at great depths, requiring strong spring systems that become impractical, and existing systems often require multiple control lines and rig-based operations for ESP replacement, leading to inefficiencies and potential formation damage.
Innovation Solution
A reliable deep-set safety valve system that uses a communication conduit for both actuator control and ESP operation, allowing for rigless removal and replacement of the actuator system and ESP, with a self-equalizing flapper valve or globe valve design that remains closed during maintenance, utilizing a communication conduit for signal control and actuator operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a deep-set safety valve is used at great depths, then well control is achieved, but the hydraulic pressure becomes very high requiring impractically strong spring systems
Solution Approach 1:
The system divides the valve assembly into two separable parts: a retrievable actuator system and a stationary valve body. This allows the actuator (including springs) to be removed and replaced without retrieving the entire valve assembly, solving the problem of inadequate spring force at depth by enabling use of stronger springs without increasing overall system depth
Solution Approach 2:
The actuator system is nested within the valve assembly, with the actuator containing the flow tube and valve mandrel components. This nested structure allows the actuator to be withdrawn from the valve body while maintaining compact packaging during installation, resolving the contradiction between needing strong springs and maintaining manageable system size
2Adaptability or versatility
If multiple control lines are used for valve control and ESP operation, then both functions can be controlled, but device complexity and installation space requirements increase
Solution Approach 1:
The actuator system serves multiple functions: it controls the safety valve through the flow tube while also serving as the ESP communication conduit. By making the actuator system multi-functional, the patent eliminates the need for separate control lines for valve operation and ESP control, reducing overall system complexity while maintaining full control capability
Solution Approach 2:
The patent combines the valve actuation mechanism and ESP control conduit into a single integrated actuator system. This merging of functions allows both valve control and ESP operation to be achieved through one communication conduit, resolving the contradiction between versatility and complexity
3Ease of repair
If a rig is used for ESP replacement, then ESP can be retrieved, but operational time and cost increase
Solution Approach 1:
By segmenting the valve assembly into a stationary valve body and a retrievable actuator system, the patent enables the actuator (and attached ESP) to be removed and replaced using simple wireline operations without requiring a rig. This segmentation allows maintenance personnel to perform ESP replacements quickly by simply withdrawing the actuator from the valve body, dramatically reducing both time and cost compared to traditional rig-based methods
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
Enables efficient and safe control of subterranean wells without the need for rig-based operations, reducing formation damage and operational costs, while ensuring fail-safe closure of the valve during ESP replacement and maintenance.
Implementation Method 1
a return spring operable to return the flow tube to an upper position upon the loss of communication in the communication conduit
Data Source
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AI summary
A method, system and apparatus is provided for a partially retrievable safety valve to control a well. The method includes securing a normally closed valve in the well. The valve may be a self-equalizing flapper valve. Following this, an actuator system operable to open the valve is run into the well. The actuator system is removable from the well while the valve remains closed and secured in the well. A submersible pump and motor may be secured to the actuator system before the actuator system is run into the well. The submersible pump and motor are also removable from the well while the valve remains closed and secured in the well. Therefore the actuator system, submersible pump and motor can be replaced or redressed, while the valve remains closed, keeping the well under control at all times.