Guided Wash Pipe Milling for Lateral Wellbore Windows
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Solution Overview
Problem
Current wellbore milling operations for lateral windows in multilateral well completions require multiple trips and risk debris accumulation due to the need for separate tool removal and insertion, and the whipstock deflection surface is vulnerable to milling damage.
Innovation Solution
A guide bar system is introduced, coupled to a whipstock and wash pipe, allowing a single trip for setting the whipstock and milling the window without decoupling from the guide bar, which guides the wash pipe to mill the window while protecting the whipstock and retaining debris.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If separate tool removal and insertion is performed for milling operations, then the milling can be performed, but multiple trips are required and debris accumulation risk increases
Solution Approach 1:
The patent combines the whipstock setting operation and the milling operation into a single continuous process. The wash pipe is coupled to the guide bar that is attached to the whipstock, allowing the mill to be run immediately after whipstock setting without removing or replacing tools. This merging of operations eliminates the need for multiple trips and prevents debris accumulation that would occur during tool removal and insertion.
2Productivity
If the wash pipe mills directly against the whipstock, then the window can be milled, but the whipstock deflection surface is vulnerable to milling damage
Solution Approach 1:
The patent introduces a guide bar as an intermediary component between the whipstock and the wash pipe mill. The guide bar is coupled to the whipstock and extends into the wash pipe, serving as a protective barrier that prevents the mill from contacting and damaging the whipstock deflection surface. The guide bar can be worn or replaced without affecting the whipstock, thus protecting the critical deflection surface while still enabling the milling operation to proceed.
Data Source
AI summary
Methods and apparatus for milling a window for a lateral wellbore in a casing string. An example method introduces a milling assembly into a primary wellbore, the milling assembly comprising: a whipstock, a guide bar coupled to the whipstock, and a wash pipe coupled to the guide bar. The method further includes running the milling assembly to a depth at which it is adjacent to the window in the casing string; securing the whipstock in the casing string; decoupling the wash pipe from the guide bar; guiding the wash pipe to mill the guide bar without milling the whipstock; and milling the window in the casing string with the wash pipe.