Downhole Isolation Valve Pressure-Actuated Sleeve
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Solution Overview
Problem
Current methods for testing the integrity of downhole liner and casing seals in oil and gas exploration are limited by the inability to directly inspect operations deep within the wellbore, and existing tools require displacement of wellbore fluids to create pressure differentials, which may not always be feasible.
Innovation Solution
A tubular isolation valve attached to a work string with an inner sleeve that moves between closed and open positions in response to pressure, allowing fluid flow only when necessary, and a method using a packer tool to pressurize the annulus and open the valve for integrity testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fluid pressure differentials are used to test seal integrity, then seal integrity can be evaluated, but wellbore fluids must be displaced which may not always be feasible
Solution Approach 1:
The valve transitions from a static closed state to a dynamic open state in response to pressure differentials. The movable valve element responds dynamically to pressure changes, opening only when the pressure differential exceeds a threshold, thereby enabling seal integrity testing without requiring complete fluid displacement of the wellbore.
Solution Approach 2:
The valve's flow state changes based on pressure differential parameters. By monitoring the pressure differential across the valve and observing whether it opens or remains closed, the system evaluates seal integrity based on parameter changes rather than requiring complete fluid displacement.
2Reliability
If the valve remains closed to isolate sections, then fluid flow is blocked, but pressure testing requires opening the valve to establish flowpath
Solution Approach 1:
The valve operates periodically between closed and open states. It remains closed during normal operation to maintain isolation, then opens temporarily when pressure differential triggers it during pressure testing, allowing the system to achieve both isolation reliability and testing capability through periodic state changes.
Solution Approach 2:
The valve is preliminarily set in the closed position to prevent fluid flow and maintain isolation. This preliminary closed state is intentionally designed to be overridden when pressure testing is required, allowing the system to first establish isolation then enable testing when needed.
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 reliable pressure testing of downhole seals by creating a flowpath only when pressure conditions indicate seal integrity issues, allowing for effective evaluation of liner top seal performance without displacing wellbore fluids.
Implementation Method 1
said inner sleeve is moveable at a predetermined pressure
Implementation Method 2
a packer tool to pressurize the annulus
Data Source
AI summary
A downhole isolation valve for testing the integrity of a tubular within a wellbore includes a tubular body with an axial through bore having a reduced diameter portion defining a valve seat and a ledge; an inner sleeve, with a closed end configured to seal within the valve seat, a shoulder spaced from that closed end, and a radial outlet positioned between the shoulder and the closed end; wherein in use the inner sleeve is selectively moveable within the bore at a predetermined pressure between a closed position, in which there is no flowpath through the bore, and an open position, in which the closed end is positioned beyond the valve seat to expose the radial outlet to the through bore beyond the valve seat and provide a flowpath through the bore of the outer tubular body.