Directional Drilling Liner Latch Couplings for Unstable Wellbores
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Solution Overview
Problem
Complex well trajectories and unstable formations in oilfield drilling lead to challenges such as hole instability, loss circulation, and stuck pipe, which increase nonproductive time and risk denying access to hydrocarbon reserves, particularly in small reservoir pockets with narrow mud windows.
Innovation Solution
A directional drilling system that allows for simultaneous wellbore drilling and liner conveyance, featuring internal and external latch couplings for selective latching and unlatching of the lining member, enabling multiple bottom hole assembly trips, hole enlargement, and cementation operations, while withstanding drilling torque and maintaining compatibility with existing tools.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional drilling methods are used in unstable formations, then drilling operations can proceed, but hole instability, loss circulation zones, and stuck pipe occur frequently, increasing nonproductive time
Solution Approach 1:
The patent applies preliminary action by installing the liner and latch couplings into the wellbore before drilling the production interval. This allows the wellbore to be stabilized and prepared in advance, preventing hole instability and loss circulation during subsequent drilling operations. The liner acts as a pre-installed structural support that eliminates the need to drill through unstable formations without protection.
Solution Approach 2:
The patent segments the drilling process into distinct phases: first installing the liner with latch couplings, then drilling the production interval, and finally retrieving the BHA. This segmentation allows each operation to be optimized independently, with the liner installation completing the stabilizing function before drilling begins, thereby eliminating nonproductive time caused by wellbore instability during drilling.
2Manufacturing precision
If the lining member is continuously conveyed during directional drilling, then accurate wellbore placement is achieved, but the bottom hole assembly must be retrieved and reinstalled for hole enlargement and cementation operations
Solution Approach 1:
The patent extracts the BHA from the liner for specific operations (hole enlargement and cementation) while leaving the liner in place with the latch couplings. This allows the BHA to be retrieved, modified, and reinstalled without removing the liner, thereby maintaining wellbore placement accuracy while enabling necessary intermediate operations. The latch couplings facilitate this by providing secure attachment points for the BHA during trips.
Solution Approach 2:
The latch couplings act as intermediaries between the liner and the BHA, enabling selective connection and disconnection. This intermediary mechanism allows the BHA to be temporarily removed for hole enlargement and cementation operations while maintaining the liner's position and the wellbore's structural integrity, thus reducing trip time compared to complete liner removal and reinstallation.
3Adaptability or versatility
If multiple bottom hole assembly trips are performed for hole enlargement and cementation, then complete well construction is achieved, but nonproductive time increases due to repeated tripping
Solution Approach 1:
The patent applies preliminary action by pre-installing the liner with latch couplings before any drilling or enlargement operations. This preliminary structural support remains in place throughout multiple BHA trips, eliminating the need to re-install protective measures during each trip. The latch couplings are pre-positioned to facilitate quick BHA attachment and detachment, reducing the time penalty associated with multiple trips for hole enlargement and cementation operations.
4Reliability
If the lining member is hung from casing latch couplings, then stable drilling operations are maintained, but the system complexity increases with additional latching mechanisms
Solution Approach 1:
The latch couplings serve multiple functions: they provide structural support for the liner, enable selective BHA attachment and detachment, and maintain wellbore stability during drilling operations. This multi-functionality reduces the need for separate systems for each function, thereby limiting the increase in overall system complexity despite the additional latching mechanisms required for stable liner conveyance and BHA trips.
Data Source
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AI summary
A method and system for directional drilling while conveying a liner, with latching parking capabilities for multiple trips, is disclosed. As the wellbore is drilled, each casing and liner is installed having upper and lower interior latch couplings. A liner to be installed below a parent casing includes an exterior latch assembly dimensioned for connection to the interior latch couplings of the parent casing. A bottom hole assembly may include upper and lower exterior inner string latch assemblies for connection to the upper and lower interior latch couplings of the liner to be installed. Such arrangement allows the liner to be conveyed and installed with the bottom hole assembly while directional drilling and for the liner to be temporarily hung from the parent casing for bottom hole assembly change-out while drilling. Float plugs dimensioned to be landed at lower liner interior latch couplings may be provided for cementing operations.