Single-Trip Open-Hole Wellbore Isolation Assembly
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Solution Overview
Problem
The existing methods for abandoning an open-hole well require multiple trips downhole, which is time-consuming and costly due to the need for multiple hydraulic and mechanical seals, often taking days to complete, especially in long wellbores.
Innovation Solution
A single-trip open-hole isolation assembly that includes an elongated liner with a bi-directional valve and a liner stabilizer, allowing for the setting of dual hydraulic seals and a mechanical barrier in a single trip, using a running tool to position and secure the liner, valve, and stabilizer within the wellbore, and injecting hardenable fluids to form cement plugs for sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple trips downhole are made to install hydraulic seals and mechanical barriers, then reliable wellbore isolation is achieved, but operation time and cost increase significantly
Solution Approach 1:
The patent combines multiple isolation functions (first hydraulic seal, mechanical barrier, second hydraulic seal) into a single integrated assembly that can be deployed in one trip. The liner assembly includes a packer for the first hydraulic seal, a valve for the mechanical barrier, and cement injection capability for the second hydraulic seal, all operable from a single deployment
Solution Approach 2:
The isolation system is segmented into distinct functional components (packer, valve, cement plug) that can be independently set and activated within the single-trip assembly, allowing each barrier to be established separately but concurrently during one operation
2Reliability
If multiple trips downhole are made to install hydraulic seals and mechanical barriers, then proper sealing is achieved, but operation cost increases due to rig equipment usage
Solution Approach 1:
The patent merges multiple sealing and isolation functions into a single deployable assembly, eliminating the need for repeated rig mobilization and demobilization. The combined assembly reduces operational costs by requiring only one trip downhole while maintaining all necessary sealing functions
Solution Approach 2:
The liner assembly serves multiple functions simultaneously: it provides the first hydraulic seal via the packer, establishes the mechanical barrier through the valve, and creates the second hydraulic seal through cement injection, making it a universal isolation solution for wellbore abandonment
3Productivity
If a single-trip assembly is used to install all isolation barriers, then operation time and cost are reduced, but device complexity increases
Solution Approach 1:
The patent employs a nested structure where the valve is positioned within the liner, the packer is collapsed within the liner during deployment, and the cement plug is injected through the liner. This nesting allows multiple components to be integrated in a compact, manageable assembly despite the complexity of functions
4Reliability
If multiple trips are made to set seals and barriers, then each component can be properly installed, but the wellbore isolation process takes days to complete
Solution Approach 1:
The patent prepares the entire isolation assembly for deployment in advance, with all components (packer, valve, cement) pre-positioned and ready for simultaneous activation. The running tool is pre-configured to set all barriers in sequence during a single trip, eliminating the need for multiple separate operations
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 reduces the time and cost of abandoning an open-hole well by enabling a dual barrier to be installed in a single trip, significantly decreasing operation time and expenses, while ensuring effective fluid isolation of the open-hole section from the wellhead.
Implementation Method 1
injecting a first hardenable fluid (e.g., cement) through the valve and into an annulus formed between the liner and the open-hole section of the wellbore to form a cement plug
Implementation Method 2
closing the valve to fluidically isolate the first portion of the interior flow passage from the second portion
Implementation Method 3
setting a liner stabilizer that is coupled to the liner
Data Source
AI summary
A method of isolating an open-hole section of a wellbore includes positioning, a liner, a valve, and a liner hanger that are attached to a working string adjacent an interface between the open-hole section and a cased section of the wellbore. The method includes injecting cement through the liner and the valve to form a first balanced cement plug within the open-hole section of the wellbore. Generally, the liner, the valve, and the liner hanger are secured within the balanced cement plug. After the balanced cement plug is set, the liner hanger is actuated and the liner, the valve, and the liner hanger are detached from the working string, which causes the valve to close and creates a mechanical barrier between the balanced cement plug and the working string. Additionally, the mechanical barrier is covered in cement to form another balanced cement plug.