Directional Washing Tool for Well Annulus Cleaning and Plugging
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Solution Overview
Problem
Current methods for plugging a well's longitudinal section are costly and weaken the casing, requiring multiple trips and complete removal of casing sections, while also failing to adequately clean the annulus before plugging.
Innovation Solution
A method involving a washing tool attached to a tubular work string for directional washing and plugging, where a perforation tool forms holes in the casing, a washing fluid cleans the annulus, and a fluidized plugging material is placed through these holes to plug both the casing and annulus in a single trip, without removing casing parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If milling technology is used to plug casing sections, then plugging can be achieved, but multiple trips are required and casing strength is weakened due to complete removal of longitudinal sections
Solution Approach 1:
The annulus is cleaned of undesirable particles and fluids before plugging material is introduced. This preliminary cleaning action ensures optimal adhesion of the plugging material to the casing and formation, eliminating the need for mechanical removal of casing sections while maintaining plugging effectiveness and casing strength.
2Reliability
If milling technology is used to plug casing sections, then plugging can be achieved, but the process is very expensive due to multiple trips into the well
Solution Approach 1:
The cleaning operation and plugging operation are merged into a single continuous process. The washing tool cleans the annulus and then the same tool or a connected tool introduces the plugging material without requiring the well to be brought in and out of service between operations, significantly reducing operational time and cost.
3Productivity
If plugging material is introduced without cleaning the annulus, then plugging can be performed, but adhesion and flow of plugging material are compromised by undesirable particles and fluids
Solution Approach 1:
The annulus is cleaned of undesirable particles and fluids before plugging material is introduced. This preliminary cleaning action ensures optimal adhesion of the plugging material to the casing and formation, eliminating the need for mechanical removal of casing sections while maintaining plugging effectiveness and casing strength.
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
This method allows for effective cleaning and plugging of the well section in one trip, maintaining casing strength and ensuring optimal plugging by removing undesirable particles and fluids before introducing the plugging material, thus enhancing the adhesion and flow of the plugging material.
Implementation Method 1
pumping a washing fluid down through the tubular work string and out into the casing via the washing tool; conducting the washing fluid radially outward into the annulus via at least one hole formed at a first location within the longitudinal section
Implementation Method 2
pumping a fluidized plugging material down through the tubular work string and out into the casing at the longitudinal section; placing the fluidized plugging material in the casing, hence also in the annulus via said holes in the casing
Data Source
Figure 1
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AI summary
Method and washing tool (24; 24') for combined cleaning of an annulus (10) in a well (2) across a longitudinal section (L1) of the well (2), and subsequent plugging of the longitudinal section (L1), wherein the method comprises the following steps: (A) conducting a perforation tool (18; 18') into a casing (8) to said longitudinal section (L1); (B) forming holes (22) in the casing (8) along the longitudinal section (L1); (C) by means of a washing tool (24; 24') conducted into the casing (8) on a tubular work string (16), pumping a washing fluid (26) through the tubular work string (16) and out into the casing (8) via the washing tool (24; 24'); (D) by means of a directional means associated with the washing tool (24; 24'), conducting the washing fluid (26) out into the annulus (10) via at least one hole (22) at a first location within the longitudinal section (L1), after which the washing fluid (26) will flow via the annulus (10) and onward into the casing (8) via at least one hole (22) formed in at least one second location within the longitudinal section (L1); (E) pumping a fluidized plugging material (50) out into the casing (8) at the longitudinal section (L1); and (F) placing the plugging material (50) in the casing (8) and in the annulus (10) along the longitudinal section (L1) so as to plug the casing (8) and the annulus (10).