Removable Scab Liner Milling for Multilateral Wellbore Access
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Solution Overview
Problem
Existing well completion methods struggle to efficiently facilitate fluid production from lateral wellbores by ensuring continuity and integrity during drilling and completion, particularly in multilateral wells, where angled scab portions complicate communication between main and lateral wellbores.
Innovation Solution
A system utilizing an anchor, production deflector, and removable scab liner is employed to re-establish continuity and integrity, enabling drill-through capabilities and allowing for the deployment of smart completions that control fluid flow from multiple lateral sections, with features like internal ridges and indicator layers aiding in angled milling and visual confirmation of cutting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a liner with an angled scab portion is run downhole into the lateral wellbore section, then the liner can be positioned to enable future communication between main and lateral wellbores, but the angled scab portion complicates the communication process and requires additional removal operations
Solution Approach 1:
The scab portion is designed as a removable component that is extracted from the liner after serving its positioning function. The milling operation removes the scab portion to create the communication pathway, separating the positioning function (scab portion) from the permanent liner structure.
Solution Approach 2:
The liner is divided into functional segments: the main liner body that remains in place, and the scab portion that is removed. This segmentation allows the scab to serve as a temporary positioning element while the liner body provides long-term structural integrity.
2Productivity
If the scab portion is removed through milling to enable communication, then fluid flow path is created, but additional operations and time are required compared to direct drilling
Solution Approach 1:
The scab portion is positioned in advance during liner installation to serve as a guide and positioning element. This preliminary positioning action simplifies the subsequent milling operation by providing a reference surface, reducing the complexity and time of the communication creation process.
Solution Approach 2:
The scab portion acts as an intermediary element between the liner and the communication pathway. It facilitates the milling operation by providing a stable surface for the milling bit to engage, enabling cleaner and more efficient removal compared to milling directly into the liner body.
3Manufacturing precision
If internal ridges are included in the scab portion, then angled milling is facilitated and cutting is improved, but the scab portion becomes more complex in structure
Solution Approach 1:
Internal ridges are added only to specific portions of the scab that require angular milling. This localized feature provides the necessary cutting guidance and precision without requiring the entire scab structure to be complex, maintaining simplicity where possible while adding precision where needed.
Data Source
AI summary
A technique facilitates production of desired well fluids from a lateral wellbore or wellbores. Aspects of the technique comprise drilling and completing the main wellbore which may include a lower lateral wellbore portion. A production deflector may be run downhole into the main wellbore, and then a lateral wellbore section, e.g. an upper lateral wellbore section, may be drilled from the main wellbore. A liner may then be run downhole and out into the lateral wellbore section. The liner comprises a scab portion which ends up disposed across the main wellbore. Subsequently, the scab portion is removed, e.g. milled, to enable communication with both the lateral wellbore section and the main wellbore extending below the lateral wellbore section.