Two-Step Expansion Plug for Wellbore Fluid Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for methods and apparatus to provide a plug inside a tubing string containing well fluid, particularly using a 2-step ball contact with deformable and rigid plug components for effective isolation and stimulation in wellbore operations.
Innovation Solution
The solution involves a plug assembly with an expandable continuous ring and a locking ring, where the expandable ring is deformed radially using a retrievable setting tool, and an untethered object is used to further expand the plug, creating a secure seal within the tubing string through a two-step expansion process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-step expansion plug is used, then the device complexity is reduced, but the reliability of fluid isolation is insufficient
Solution Approach 1:
The plug is divided into two distinct expansion stages: a first expansion phase using a setting tool to expand the plug body to a first diameter, and a second expansion phase using fluid pressure to expand the plug body to a second diameter. This segmentation of the expansion process into separate steps enhances isolation reliability while managing structural complexity through a modular design approach.
Solution Approach 2:
The setting tool performs a preliminary expansion action to establish an initial seal and positioning of the plug before the final expansion. This preliminary action ensures the plug is properly seated and provides a baseline isolation, upon which the second expansion phase builds to achieve the final isolation reliability required for wellbore operations.
2Reliability
If a two-step expansion plug is used, then the fluid isolation reliability is improved, but the ease of operation becomes more difficult
Solution Approach 1:
The plug incorporates a self-expanding mechanism where fluid pressure differential automatically triggers the second expansion phase. After the initial expansion by the setting tool, the plug is designed to respond autonomously to pressure changes, eliminating the need for additional manual intervention or complex control systems, thereby maintaining ease of operation despite the two-step process.
Solution Approach 2:
The second expansion phase utilizes hydraulic principles where fluid pressure differential across the plug body drives the expansion mechanism. This pneumatic/hydraulic self-actuation simplifies operation by leveraging the existing wellbore fluid system to complete the expansion process without requiring additional mechanical intervention.
3Strength
If the expandable ring is made rigid, then the strength increases, but the adaptability to tubing string variations decreases
Solution Approach 1:
The plug body incorporates dynamic elements that allow it to transition between rigid and flexible states. The expandable ring structure can deform radially during the expansion process to adapt to tubing variations, then lock into a rigid configuration once expanded, providing both adaptability during installation and strength during operation.
Solution Approach 2:
The plug design allows for parameter changes in the physical state of the expandable ring. Before expansion, the ring maintains a flexible, compressed state that can accommodate variations in tubing diameter. Upon expansion, the ring transitions to a rigid, expanded state with fixed dimensional parameters, providing the necessary strength and positional stability for reliable fluid isolation.
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 method enables effective isolation and stimulation by providing a reliable seal within the tubing string, allowing for efficient fluid management and operation in wellbore environments.
Implementation Method 1
the expandable ring is deformed radially using a retrievable setting tool
Implementation Method 2
an untethered object is used to further expand the plug, creating a secure seal
Data Source
AI summary
A plug assembly includes an expandable assembly and a locking ring. The expandable assembly is adapted to be deformed radially over the locking ring. The locking ring has a stopping inner surface. The plug assembly is used with an untethered object, which has an outer surface adapted to couple with the stopping inner surface of the locking ring. The untethered object is also adapted to contact an inner surface of the plug assembly and, using well fluid pressure, to apply forces to the plug assembly. The forces cause the longitudinal movement of the untethered object while contacting the inner surface of the plug assembly until the untethered object contacts the stopping inner surface of the locking ring.