Floating Piston Seal Assembly for Irregular Nipples
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current surface-controlled, subsurface safety valves (SCSSVs) and plugs face issues with proper sealing due to damaged or irregularly shaped landing nipples, leading to potential well safety hazards and the need for costly and time-consuming workovers.
Innovation Solution
A plug design featuring a mandrel with a compressible seal and a piston that creates a pressure differential to compress the seal against the nipple's inner and outer surfaces, ensuring a fluid-tight seal even on irregular surfaces, using a seal assembly with V-seals and pistons to maintain sealing contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional SCSSV or plug is used in a damaged nipple, then the valve operation may be affected, but the sealing reliability deteriorates due to surface irregularities preventing proper sealing
Solution Approach 1:
The seal assembly changes the physical state and properties of the sealing interface by introducing a compliant, deformable seal element that can adapt to varying surface conditions. The seal material properties are specifically designed to deform and conform to irregular surfaces, transforming the sealing mechanism from rigid-to-rigid contact to compliant adaptation, thereby maintaining sealing reliability despite nipple surface irregularities
Solution Approach 2:
The seal assembly employs a flexible seal element that can deform and conform to the irregular inner surface of the damaged nipple. This flexible sealing component adapts to surface irregularities such as gouges, grooves, and ridges, ensuring reliable sealing contact where conventional rigid sealing mechanisms would fail
2Reliability
If workover operations are performed to replace damaged nipples, then sealing reliability improves, but the loss of time and productivity increase significantly
Solution Approach 1:
The seal assembly performs self-adjustment by automatically conforming to the damaged nipple surface through elastic deformation of the seal element. The seal self-adapts to irregularities without requiring external intervention, precision alignment, or specialized installation procedures, thereby eliminating the need for time-consuming workover operations to replace damaged nipples
Solution Approach 2:
The seal assembly is pre-configured with compliant material properties and geometric characteristics that enable it to automatically adapt to various nipple surface conditions upon installation. This preliminary design ensures that the seal will self-conform to irregular surfaces without requiring subsequent adjustment operations or nipple replacement
3Ease of operation
If hydraulic pressure is applied to maintain SCSSV open position, then the valve remains operational, but any pressure loss causes the valve to close, creating operational vulnerability
Solution Approach 1:
The seal assembly utilizes hydraulic pressure differentials across the piston to automatically control seal compression. When wellbore pressure exceeds annular pressure, the pressure differential drives the piston to compress the seal against the nipple, maintaining sealing reliability without requiring external control systems or continuous hydraulic monitoring
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 seals the annulus between the SCSSV or plug and the nipple, preventing fluid leakage and ensuring safe well operation by maintaining sealing contact despite surface irregularities, thus reducing the need for frequent workovers.
Implementation Method 1
a piston that creates a pressure differential to compress the seal against the nipple's inner and outer surfaces
Implementation Method 2
a seal that is compressible against an outer surface of the mandrel and an inner surface of the bore
Data Source
AI summary
Methods and apparatus for sealing a plug within tubing that the plug is designed to be landed and set in are disclosed. The plug includes a seal assembly having a seal on the plug that is acted on by a piston. Wellbore fluid pressure acts on the piston when the valve is closed, thereby moving the piston to force the seal into sealing contact with an inside surface of the tubing.