Liner Cementing via Inner String to Remove Shoe Track
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional well construction methods result in the creation of a cement-filled shoe track, which requires time-consuming drilling operations, potentially affecting the integrity of the cement and breaching problematic formations, especially in deep-water or sub-sea locations.
Innovation Solution
A method involving an inner string to deliver settable material directly to the annulus, eliminating the need for a cement-filled shoe track, and allowing for the reconfiguration of the liner to permit fluid flow from hydrocarbon-bearing formations, while also enabling geophysical data collection through pilot bore drilling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cementing methods with float collar and shoe track are used, then cement is protected from well fluid contamination, but time-consuming drilling operations are required to remove the cement plug
Solution Approach 1:
The invention extracts and eliminates the shoe track cement plug by delivering cement directly to the annulus through the inner string, bypassing the need to create and subsequently drill out a cement plug in the shoe track. This removes the harmful element (cement plug requiring drilling) while maintaining the beneficial function (cement protection).
Solution Approach 2:
The inner string is positioned and ready before cementing begins, with the distal end already at the shoe. The cement is delivered directly through the inner string to the annulus, performing the cementing action in advance without requiring subsequent drilling operations to remove a plug.
2Manufacturing precision
If a drill bit slightly smaller than casing internal diameter is used to remove cement, then complete cement removal is achieved, but the drill bit must be retrieved and replaced if bore extension is needed
Solution Approach 1:
The invention extracts the cement plug elimination function from the drilling process. By delivering cement directly to the annulus through the inner string, the system eliminates the need to drill out a shoe track plug, thereby removing the constraint that would require drill bit retrieval and replacement for bore extension operations.
3Quantity of substance
If cement is pumped through the running string and liner, then the annulus is completely filled, but a solid cement plug remains in the shoe track requiring drilling removal
Solution Approach 1:
The inner string acts as an intermediary delivery system for the cement slurry. Instead of pumping cement through the running string and liner (which creates a plug), the inner string delivers cement directly to the annulus at the shoe, serving as a mediator that enables precise cement placement without creating a removable plug.
Solution Approach 2:
The invention segments the cement delivery path from the running string/liner system to a separate inner string system. This segmentation allows cement to be delivered independently directly to the annulus, separating the cementing function from the liner installation function and eliminating the shoe track plug creation.
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 approach reduces the risk of breaching problematic formations, saves time by avoiding cement drilling, and allows for immediate access to hydrocarbon-bearing formations without the need for cement removal, enhancing operational efficiency and safety in deep-water environments.
Implementation Method 1
pumping a settable material from surface, through the inner string, and through the shoe to at least partially fill an outer annulus surrounding the liner
Implementation Method 2
When the cement cures the operator is left with a solid plug of cement inside the shoe track
Data Source
AI summary
A well construction method, and corresponding apparatus, in which a drilled bore (106) is lined with a plurality of successively smaller diameter sections of bore-lining tubing includes at least one casing (108, 110, 112) and at least one liner (120). The well construction method comprises: drilling a final section of a bore (106) to intersect a hydrocarbon-bearing formation (130); providing a shoe (134) at a distal end of a liner and a running tool (150) at a proximal end of the liner, and coupling an inner string (140) between the shoe (134) and the running tool (150); running the liner (120) into the final section of the bore (106) such that the liner extends into the hydrocarbon-bearing formation (130); pumping a settable material (116) from surface (104), through the inner string (140), and through the shoe (134) to at least partially fill an outer annulus (114) surrounding the liner (120); and retrieving the inner string (140) and the running tool (150).