Annulus Washing Tool Pressure Reduction Apparatus
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Solution Overview
Problem
Current methods for washing annuli in wells are inefficient, particularly in removing debris and cement sheaths, which can lead to increased operational time and safety risks due to pressure surges and the generation of large volumes of swarf during casing removal for well abandonment.
Innovation Solution
A method involving a tool with a pressure reduction apparatus that injects washing fluid into the annulus, creating a localized reduction in pressure within the casing to facilitate the flow of debris and cement back into the casing, utilizing swirling fluid dynamics to enhance flow velocity and efficiency, and allowing for cementing operations with improved bond quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If mechanical cutting and pulling is used to remove casing, then casing can be removed, but it becomes more difficult and time consuming as casing becomes more stuck in unconsolidated material
Solution Approach 1:
The patent replaces mechanical cutting and pulling methods with a hydrodynamic jet system. High-pressure fluid jets are used to erode and remove the unconsolidated material and cement sheath from the casing annulus, enabling easier and faster casing removal without mechanical contact that becomes stuck in the material.
Solution Approach 2:
The invention uses hydraulic principles by directing high-pressure fluid jets into the annulus to remove debris and cement sheath. The fluid dynamics create a cleaning action that eliminates the need for mechanical tools to physically cut and pull stuck casing, significantly improving removal efficiency.
2Productivity
If milling is used to remove stuck casing, then casing can be removed, but it produces large volumes of swarf that require disposal
Solution Approach 1:
The patent substitutes mechanical milling operations with a hydrodynamic jet cleaning system. Instead of mechanically removing material through cutting and milling that generates swarf, high-pressure fluid jets erode and flush the unconsolidated material and cement sheath, eliminating swarf generation while maintaining casing removal capability.
3Productivity
If perf and wash technique is used, then annulus can be flushed to remove debris, but pressure surge may cause tool to be urged back through casing towards surface
Solution Approach 1:
The patent segments the annulus cleaning process into multiple zones with controlled fluid injection. By using multiple nozzles positioned at different locations and controlling fluid flow to specific annular regions, the system achieves effective cleaning while managing pressure distribution to prevent dangerous surges that would urge the tool back towards the surface.
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 method effectively removes debris and cement sheaths, reduces operational time, and enhances the safety of well abandonment procedures by minimizing pressure surges and improving cement bonding within the annulus.
Implementation Method 1
utilizing swirling fluid dynamics to enhance flow velocity and efficiency
Implementation Method 2
creating a localized reduction in pressure within the casing to facilitate the flow of debris and cement back into the casing
Implementation Method 3
flowing a washing fluid from an injection aperture on the tool into the annulus through a first casing aperture in the casing
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
Some examples of the present disclosure relate to a method for washing an annulus that at least partially surrounds a casing in a well. The method comprises locating a tool inside a wellbore casing, and flowing a washing fluid from an injection aperture on the tool and into the annulus via a first casing aperture in the casing. An inflow region of the casing is created having a reduced pressure relative to the annulus, and the method involves flowing the washing fluid from the annulus and into the inflow region of the casing through a second casing aperture in the casing.