Annular Barrier Valve Unit for Cement Retention During Expansion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing annular barriers in well completion processes risk cement being sucked back into the casing if pressure is released prematurely before cement setting, leading to undesirable outcomes.
Innovation Solution
An annular barrier with an expandable metal sleeve and a valve unit that includes a piston system with a shear element, allowing controlled expansion without complete pressure release, ensuring the cement remains in place during the setting process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pressure is released before cement has set, then the annular barrier can be expanded, but cement may be sucked back into the casing
Solution Approach 1:
The valve unit is pre-configured with the unit piston in the first position during run-in, establishing pressure equalization between the annular space and annulus before expansion. This preliminary positioning prevents premature pressure release that would cause cement to be sucked into the casing.
Solution Approach 2:
The system changes the pressure parameter control by using a shear element that maintains pressure until a predetermined force is reached, then allows controlled pressure release. This parameter change enables barrier expansion while preventing cement suction by maintaining pressure during the critical setting period.
2Reliability
If pressure is maintained to prevent cement suction, then cement remains in place, but the annular barrier cannot be expanded
Solution Approach 1:
The valve unit transitions from a static pressure maintenance state to a dynamic expansion state through the shear element mechanism. The unit piston moves from the first position (pressure equalization) to the second position (expansion) when the predetermined force is reached, enabling the barrier to expand while maintaining cement retention through controlled pressure management.
Solution Approach 2:
The system changes the pressure parameter from a constant maintained state to a controlled release state. The shear element shears at a predetermined force, allowing pressure to be released controlledly for expansion while preventing complete pressure loss that would cause cement suction, thus achieving both cement retention and barrier expansion.
3Reliability
If a shear element is used to control pressure release, then controlled expansion is achieved, but the device complexity increases
Solution Approach 1:
The valve unit merges multiple functions into a single integrated assembly: the unit piston, shear element, piston sleeve, and aperture system are combined into one compact unit. This merging achieves controlled expansion functionality while minimizing the increase in device complexity through functional integration.
Solution Approach 2:
The shear element automatically shears when the predetermined force is reached, enabling self-actuated transition from the first position to the second position without external control mechanisms. This self-service feature simplifies the overall control system while maintaining reliable controlled expansion.
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
Prevents cement from being sucked into the casing by maintaining pressure until the expansion position is reached, ensuring effective zonal isolation and cement retention.
Implementation Method 1
a shear element preventing movement of the unit piston from the first position to the second position until a predetermined force is reached
Implementation Method 2
the second aperture is in fluid communication with the third aperture in the first position so that pressure equalisation between the annular space and the annulus occurs
Implementation Method 3
pressurised fluid from the expansion opening to the expandable space for expanding the expandable metal sleeve
Data Source
AI summary
The present invention relates to an annular barrier for providing zonal isolation in an annulus downhole between a well tubular metal structure and another well tubular metal structure or a wall of a borehole, comprising a tubular metal part configured to be mounted as part of the well tubular metal structure and having an inside and an axial extension along the well tubular metal structure, an expandable metal sleeve surrounding the tubular metal part, each end of the expandable metal sleeve being connected with the tubular metal part, defining an expandable space between the expandable metal sleeve and the tubular metal part, and an expansion opening in the tubular metal part through which fluid enters in order to expand the expandable metal sleeve, wherein the annular barrier further comprises a valve unit having a first position and a second position; in the second position for leading pressurised fluid from the expansion opening to the expandable space for expanding the expandable metal sleeve, the valve unit comprises a first aperture in fluid communication with the expansion opening, a second aperture in fluid communication with the annulus and a third aperture in fluid communication with the expandable space. The invention also relates to a downhole system comprising the annular barrier and the well tubular metal structure.