Hydraulically Actuated Plug Valve for Tubing Annulus Pressure Control
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Solution Overview
Problem
Existing subsea wellhead tubing hangers lack reliable solutions for efficiently communicating and controlling fluid flow between the production tubing and the tubing annulus, particularly in offshore operations, due to the limitations of conventional tubing annulus valves.
Innovation Solution
A tubing hanger with a hydraulically actuated plug valve that allows for selective opening and closing of the annulus passage, featuring a solid plug valve stem and pressure equalization passages to maintain pressure balance and prevent fluid pressure from moving the valve stem, eliminating the need for wireline retrieval of plugs and enhancing reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional tubing annulus valve is installed, then fluid flow control between production tubing and annulus is achieved, but reliability is insufficient due to valve failure and sticking issues
Solution Approach 1:
The patent replaces conventional mechanical valve designs with a hydraulically actuated plug valve system. The valve stem is moved between open and closed positions by hydraulic pressure applied through a hydraulic actuator, eliminating the need for complex mechanical linkages and improving reliability by using fluid pressure directly to control the plug position.
Solution Approach 2:
The invention employs hydraulic principles to actuate the valve stem. A hydraulic actuator applies fluid pressure to move the plug between open and closed positions, and a hydraulic release mechanism allows controlled opening. This hydraulic system provides reliable actuation and eliminates sticking issues associated with mechanical valves.
2Ease of operation
If a wireline retrieval method is used for plug removal, then plug retrieval is possible, but operation complexity and time are increased
Solution Approach 1:
The valve system is designed to be self-actuating through hydraulic pressure. The hydraulic actuator automatically moves the plug to the open position when hydraulic pressure is applied, eliminating the need for wireline retrieval operations. The system serves itself by using hydraulic force to perform the retrieval function that would otherwise require complex wireline operations.
3Stability of the object's composition
If pressure equalization passage is added, then pressure balance is maintained preventing valve stem movement, but device complexity increases
Solution Approach 1:
The pressure equalization function is achieved by segmenting the internal flow paths. A pressure equalization passage is provided that allows pressure to equalize between the upper and lower ends of the valve stem. This segmentation of flow paths enables pressure balance without requiring complex external pressure control systems.
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 hydraulically actuated valve stem provides reliable and efficient control of fluid flow between the production tubing and annulus, reducing the need for wireline operations and ensuring consistent performance by preventing pressure-induced valve movement and allowing for easy retrieval in case of failure.
Implementation Method 1
The valve stem is hydraulically actuated for movement between the open and closed positions. The valve stem has an annulus piston band located between the upper and lower ends that are acted on by the hydraulic pressure.
Implementation Method 2
The pressure equalizing passage equalizes pressure in the annulus passage at the upper and lower ends of the valve stem while the valve stem is in the open position.
Data Source
AI summary
A tubing hanger lands in a tubular outer wellhead member and supports a string of production tubing. The tubing hanger has a production passage for communicating with the interior of the production tubing and an annulus passage for communicating with a tubing annulus on the exterior of the production tubing. An access port leads from the annulus passage to an exterior portion of the body for communicating the tubing annulus with the annulus passage. A valve stem is movable along an axis of the annulus passage between a closed position, blocking the access port, and an open position, exposing the annulus port. A pressure equalizing passage extends from the annulus passage above the valve stem to the annulus passage below the valve stem.