Casing Section Displacement for Zonal Isolation Integrity
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Solution Overview
Problem
Existing methods for achieving zonal isolation in subterranean formations are inadequate due to issues like improper setting of zonal isolation materials, shrinkage, fluid migration, and mechanical and thermal stresses leading to fractures and debonding, resulting in fluid migration between zones, loss of production, and environmental hazards.
Innovation Solution
A method involving the operative displacement of a casing section within a wellbore to effect at least partial interference of fluid passages by expanding or deforming the casing section using tools like split-rings or tapered mandrels and sleeves, ensuring retention in a displaced position to prevent reversion and maintain zonal isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If zonal isolation material is provided within the wellbore to isolate zones, then zonal isolation is achieved, but the zonal isolation material may be subjected to mechanical and thermal stresses leading to fractures, cracks, and debonding
Solution Approach 1:
The patent introduces a compliant intermediary layer between the rigid casing and the zonal isolation material. This compliant layer absorbs and mitigates mechanical and thermal stresses, preventing them from being transmitted to the zonal isolation material, thereby maintaining its integrity and preventing fractures, cracks, and debonding
Solution Approach 2:
The patent modifies the mechanical properties of the annular space by introducing a compliant material that changes the stress distribution parameters. This compliant material has different elastic modulus and Poisson's ratio compared to traditional rigid packers, allowing it to accommodate thermal expansion and contraction while maintaining zonal isolation
2Reliability
If sealant containing particles is injected into narrow pathways to remediate channels and micro-annuli, then remediation is attempted, but the narrow pathways present excessive resistance to flow of the injected sealant
Solution Approach 1:
The patent applies local quality by targeting specific defective zones with the sealant composition. The sealant is injected only into areas where channels and micro-annuli are detected, rather than treating the entire annulus. This localized approach reduces flow resistance and improves injectability while maintaining effectiveness
Solution Approach 2:
The patent uses a composite sealant material that combines particles with a carrier fluid having optimized rheological properties. This composite formulation allows the sealant to flow through narrow pathways with reduced resistance while maintaining its ability to plug defects once injected
3Reliability
If the casing section is displaced to interfere with fluid passages, then fluid migration is mitigated, but the casing section may revert to its original position
Solution Approach 1:
The patent employs a retention mechanism that is pre-configured to engage with the displaced casing section. This preliminary action ensures that once the casing is displaced to the desired position to occlude fluid passages, it is immediately secured and prevented from reverting, maintaining stable occlusion
Solution Approach 2:
The patent introduces a retention mechanism as an intermediary component between the displaced casing section and the wellbore environment. This retention mechanism acts as a mediator that holds the casing in its displaced position, preventing reversion while allowing the casing to maintain its occlusive function
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 approach effectively mitigates fluid migration between zones by ensuring the zonal isolation material is positioned opposite a relatively impermeable formation, maintaining the integrity of the seal and preventing fluid communication, thus enhancing production efficiency and safety.
Implementation Method 1
effecting deformation of the casing section
Implementation Method 2
effecting expansion of the casing section
Implementation Method 3
effecting retention of the casing section in the displaced position or in substantially the displaced position
Implementation Method 4
the effecting retention is effected by the expanded split-ring
Implementation Method 5
at least partial occlusion of the fluid passage
Data Source
AI summary
There is provided a method for effecting at least partial interference of a fluid passage extending between a casing, disposed within a wellbore that is penetrating a subterranean formation, and the subterranean formation. The method includes detecting the fluid passage, and effecting an operative displacement of a casing section of the casing such that at least partial interference of the fluid passage is effected.