Dual Barrier Perforating System for Wellbore Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for sealing oil and gas wellbores during abandonment fail to effectively prevent fluid migration between the casing and the wellbore annulus, necessitating improved sealing technologies to meet regulatory and environmental standards.
Innovation Solution
A system and process involving upper and lower assemblies with perforating guns and expandable sealing elements that introduce a sealing fluid to form a fluid-impermeable plug within the annulus, using a combination of mechanical barriers and a sealing fluid that transitions from liquid to solid to create a comprehensive seal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional sealing methods are used in wellbore abandonment, then the sealing process is simple, but fluid migration between casing and annulus cannot be prevented
Solution Approach 1:
The sealing system is divided into multiple independent components: upper and lower packers with expandable sealing elements, a float collar with check valves, and a perforating gun assembly. Each component addresses a specific sealing challenge, allowing the system to achieve comprehensive sealing effectiveness while maintaining manageable complexity through modular design.
Solution Approach 2:
The assembly uses nested configuration where the float collar is positioned within the packer assembly, the perforating gun is housed within the float collar, and multiple sealing elements are arranged concentrically. This nesting approach reduces overall device complexity by optimizing space utilization while maintaining effective sealing across multiple barriers.
2Reliability
If mechanical barriers alone are used for sealing, then the sealing structure is simple, but fluid flow cannot be completely prevented
Solution Approach 1:
The sealing system utilizes parameter changes by employing expandable sealing elements that change their physical state from compressed to expanded when actuated. This transformation allows the sealing elements to transition from a retracted position to a fully expanded sealing position, creating effective fluid flow prevention while maintaining a compact stored configuration.
Solution Approach 2:
The float collar incorporates check valves that utilize phase transition principles to control fluid flow direction. The valve mechanism transitions between open and closed states based on pressure differential, automatically preventing reverse flow and enhancing the reliability of fluid flow prevention without requiring complex active control systems.
3Reliability
If multiple assemblies are used to seal both annulus and casing interior, then sealing completeness is improved, but operation complexity increases
Solution Approach 1:
The upper and lower packers, float collar, and perforating gun are combined into a single integrated assembly that can be lowered and set as one unit. This merging of multiple sealing functions into one operable assembly maintains sealing completeness while significantly easing operation, as the entire multi-component system can be controlled through a single setting tool rather than requiring separate operations for each component.
Solution Approach 2:
The integrated assembly performs multiple functions simultaneously: the packers provide mechanical sealing barriers, the float collar with check valves controls fluid flow direction, and the perforating gun creates access holes. This multi-functionality within a single operable unit achieves sealing completeness while reducing operational complexity compared to managing separate assemblies for each 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
The solution effectively seals both the annulus between the wellbore and casing, as well as inside the casing, preventing fluid flow and meeting regulatory requirements by forming a reliable, impermeable barrier.
Implementation Method 1
using a combination of mechanical barriers and a sealing fluid that transitions from liquid to solid to create a comprehensive seal
Data Source
AI summary
A system and method for use in used in oil and gas wellbores is provided. More specifically, the disclosure relates to barriers or seals used in downhole operations involving activities such as perforating operations and well abandonment operations. The system and method relate to sealing a borehole such as when a well is being abandoned at the end of its productive life. The embodiments are particularly applicable to boreholes containing casing with an inner wall and an outer wall wherein an annulus is formed between the outer wall of the casing and the borehole wall.