Dynamic Pressure Control for Annulus Barrier Injection
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Solution Overview
Problem
Existing methods for forming barriers in well annuli, such as those using cement or polymeric hardening liquids, face challenges with reliability and leakage, particularly under differential pressure conditions, and are ineffective in repairing leaking packers.
Innovation Solution
A device comprising an injection tool and a pump unit that introduces a polymeric hardening liquid into the annulus with controllable pressure, starting at a low initial pressure and increasing to a higher final pressure over time, allowing the liquid to penetrate and fill cracks effectively, forming a high-quality barrier.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polymeric hardening liquid is introduced into the annulus with constant pressure, then the injection process is simple, but the barrier quality is insufficient under differential pressure conditions
Solution Approach 1:
The pump unit dynamically adjusts the injection pressure over time, transitioning from an initial pressure to a final pressure that is higher than the initial pressure. This dynamic pressure control allows the system to adapt to the changing viscosity of the hardening liquid and ensure effective penetration into cracks while maintaining barrier quality under differential pressure conditions.
Solution Approach 2:
The invention changes the pressure parameter during the injection process. By controlling the pressure to increase from an initial value to a final value higher than the initial pressure, the system optimizes the injection process for different stages of liquid hardening, ensuring reliable barrier formation without requiring an overly complex device.
2Reliability
If cement is used to form the annulus barrier, then the barrier is initially strong, but it can leak water or hydrocarbons between zones or to the surface
Solution Approach 1:
The polymeric hardening liquid undergoes a parameter change from liquid to solid state through hardening, transforming its properties during injection. This phase transition allows the material to flow initially for crack penetration, then set to form a reliable barrier that prevents leakage of water or hydrocarbons, addressing the limitations of cement.
Solution Approach 2:
The invention uses polymeric hardening liquid as an alternative to traditional cement, leveraging the unique properties of polymeric materials that can transition from fluid to solid state. This composite approach provides superior sealing capability while eliminating the leakage issues associated with cemented barriers.
3Manufacturing precision
If high pressure is applied during liquid injection, then the liquid penetrates cracks effectively, but the liquid may not have sufficient time to harden properly
Solution Approach 1:
The pump unit employs dynamic pressure control, applying higher pressure at later stages of injection when the liquid has had time to harden. This dynamic adjustment ensures that crack penetration occurs effectively without compromising the hardening process, as the pressure increases from an initial level to a final level higher than the initial pressure during the injection duration.
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 device improves the reliability and quality of the barrier formed in the annulus by ensuring the polymeric hardening liquid penetrates larger cracks first and then fills smaller ones, providing enhanced sealing capabilities even under differential pressure.
Implementation Method 1
the polymeric hardening liquid relates to a polymeric based liquid that is hardening with time, i.e. the viscosity of the hardening liquid increases from a pumpable liquid to a none pumpable paste, and being a solid at the final stage
Data Source
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AI summary
A device (1) for forming a barrier in an annulus (5) of a well (11). The device comprises an injection tool (20) adapted to introduce a polymeric hardening liquid in through an opening in the annulus (5), and a pump unit (26) adapted to provide pressure to said liquid so that the liquid is introduced into the opening in the annulus with a controllable pressure. The device comprises a control unit (30) adapted to control the pump unit (26) so that said liquid is provided into the opening with an initial pressure at a start-up phase of introducing the liquid into the opening and a final pressure at a close-down phase of introducing the liquid into the opening, wherein the final pressure is higher than the initial pressure.