Nested Tubular Actuator for Downhole Expansion
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Solution Overview
Problem
Monobore expansion systems in the downhole hydrocarbon recovery industry require a seal between an expanded liner and an open hole, which is currently achieved through time-consuming and undesirable cementing operations due to the large annular gap, necessitating a more efficient actuation method for downhole tools.
Innovation Solution
A downhole actuator comprising nested tubulars with differing longitudinal contraction properties that radially expand, allowing for the actuation of downhole tools without the need for separate actuation runs, utilizing a discontinuous tubular design with web-structured walls and tensile support members to transmit tension and facilitate longitudinal contraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cementing operation is used to seal the liner to the open hole, then sealing reliability is improved, but operation time and complexity increase
Solution Approach 1:
The actuator is divided into multiple nested tubular segments with different longitudinal contraction properties. When radially expanded, these segments contract longitudinally at different rates, generating the actuating force needed to move the downhole tool without requiring cementing operations.
Solution Approach 2:
The actuator utilizes dynamic longitudinal contraction during radial expansion to generate actuating force. The discontinuous tubular structure with web-structured walls and tensile support members allows controlled longitudinal movement that translates the expansion motion into tool actuation, eliminating the need for static cementing seals.
2Reliability
If a separate actuation run is performed to actuate the downhole tool, then actuation reliability is improved, but device complexity and operation time increase
Solution Approach 1:
The actuator combines the liner expansion function with the tool actuation function into a single integrated operation. By nesting the actuator tubulars within the liner and configuring them with different contraction properties, the system merges two separate operations (expansion and actuation) into one unified process, reducing complexity while maintaining reliability.
Solution Approach 2:
The actuator serves multiple functions: it acts as a structural component during expansion and simultaneously generates the actuating force for the downhole tool. The nested tubular structure with differential contraction properties enables a single component system to perform both expansion support and tool actuation, eliminating the need for separate actuation runs.
3Productivity
If the liner is expanded without a seal, then expansion speed and simplicity are improved, but sealing capability deteriorates
Solution Approach 1:
The actuator's nested tubular structure with different longitudinal contraction properties generates its own actuating force through the expansion process itself. The differential contraction between tubular segments creates the necessary longitudinal movement to actuate the downhole tool, allowing the expansion operation to serve dual purposes without requiring separate sealing or actuation 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
Enables efficient actuation of downhole tools, such as packers, by reducing the need for cementing operations, thereby saving time and resources for well operators by allowing for direct sealing of the expanded liner to the open hole.
Implementation Method 1
at least two nested tubulars having differing longitudinal contraction properties consequent simultaneous radial expansion
Implementation Method 2
a discontinuous tubular being configured to restrict longitudinal expansion while longitudinally contracting in response to radial expansion
Data Source
AI summary
Disclosed herein is a downhole actuator. The actuator includes, a discontinuous tubular being configured to restrict longitudinal expansion while longitudinally contracting in response to radial expansion.