Downhole Plug Assembly Fluid Barrier via Untethered Object
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing well perforation and stimulation techniques face challenges in forming effective fluid barriers in tubing strings, particularly in maintaining mechanical integrity and allowing for the passage of equipment, while also requiring temporary and efficient operation.
Innovation Solution
A plug assembly is deployed downhole with a tubular main body, a sealing ring, and a ratcheting seal retainer that radially and axially translates to form fluid seals, allowing an untethered object to block the passageway and create a fluid barrier, with components potentially made from degradable materials for temporary operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a plug assembly is used to form a fluid barrier in a tubing string, then reliable fluid sealing is achieved, but the mechanical integrity and equipment passage capability are compromised
Solution Approach 1:
The plug assembly is divided into distinct functional segments: a sealing element for fluid barrier formation, a seal retainer for positioning, and a main body for structural support. This segmentation allows each component to perform its specific function optimally while maintaining overall system reliability without excessive complexity
Solution Approach 2:
The sealing function is extracted as a separate sealing element that can be independently positioned and energized by the seal retainer. This extraction allows the fluid barrier capability to be maintained while the main body remains relatively simple and permissive to equipment passage
2Duration of action of stationary object
If degradable materials are used for temporary operation, then the temporary integrity is ensured, but the duration of action is limited
Solution Approach 1:
The material properties of the plug assembly components are changed to be degradable over time. This parameter change allows the plug to maintain mechanical integrity and fluid sealing capability during the required operational timeframe, then automatically disintegrate after completing its temporary function, eliminating the need for retrieval operations
3Ease of operation
If the passageway dimension is larger than the untethered object, then equipment passage is allowed, but the fluid barrier formation is challenged
Solution Approach 1:
The sealing mechanism transitions from relying solely on passageway fit to utilizing radial expansion in a different dimension. The sealing element is energized radially outward by the seal retainer to contact the passageway walls, creating a reliable fluid barrier even when the passageway is larger than the untethered object, while still allowing equipment passage
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 enables the formation of reliable fluid barriers that enhance well stimulation operations, such as hydraulic fracturing, while allowing equipment passage and ensuring temporary integrity through degradable materials that disintegrate after the operation.
Implementation Method 1
a sealing element of the plug assembly to be energized against a wall of the tubing string and be energized against the body of the plug assembly
Data Source
AI summary
A technique includes running a plug assembly inside a tubing string of a well; deploying an untethered object in the tubing string; and communicating the untethered object into a passageway of the plug assembly to land the untethered object in a seat of the plug assembly. The passageway has a maximum cross-sectional dimension that is larger than a maximum cross-sectional dimension of the untethered object. The technique includes using the landed untethered object to form a fluid barrier in the tubing string.