Concentric Liner Drilling with Inner String Retrieval
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Solution Overview
Problem
Current methods for installing liners in oil and gas wells do not allow for the retrieval and re-run of bottom hole assemblies during drilling, limiting the length of drilling and preventing the use of directional steering tools and logging instruments without removing the entire liner string, and there are no established methods to support the liner from buckling when disconnected from the drill pipe.
Innovation Solution
Concentric inner and outer tubular strings are used with a drilling bottom hole assembly at the lower end, where the liner hanger is set and then retrieved to allow for cementing, and the inner string is re-run with a liner hanger control tool to support the liner in tension, preventing buckling by maintaining pressure in an annular chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the liner is suspended on a drill pipe during drilling, then the bottom hole assembly can be retrieved and rerun, but the drill pipe diameter is much smaller than the liner and has no room for bottom hole assembly retrieval
Solution Approach 1:
The patent employs a nested configuration where a smaller inner drill pipe is positioned inside the larger outer liner. The inner drill pipe serves as the suspension medium during drilling operations, while the annular space between the inner and outer strings provides the necessary clearance for bottom hole assembly retrieval and rerunning. This nested arrangement allows the system to overcome the diameter limitation by utilizing the space between concentric tubulars rather than requiring the drill pipe itself to be large enough for BHA passage.
2Reliability
If the liner hanger is set to support the liner, then the liner is secured in place, but the liner may buckle when disconnected from the drill pipe
Solution Approach 1:
The patent applies preliminary action by setting the liner hanger to support the liner weight before the actual drilling or cementing operations begin. The hanger is installed and secured in advance, creating a stable support structure that prevents liner buckling during subsequent disconnection and retrieval operations. This preliminary support mechanism ensures the liner maintains its structural integrity throughout the drilling process.
3Ease of repair
If the entire liner string is removed to retrieve tools, then the bottom hole assembly can be accessed, but the operation becomes complex and time-consuming
Solution Approach 1:
The patent divides the liner system into separable components: the outer liner string and the inner drill pipe with bottom hole assembly. This segmentation allows the bottom hole assembly to be independently retrieved through the annular space between the concentric strings without requiring removal of the entire liner. The modular design enables tool access and maintenance operations to be performed on the BHA while the liner remains in place, significantly reducing operational complexity and time requirements.
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
Enables the retrieval and re-run of bottom hole assemblies during liner drilling, allowing for deeper drilling and the use of directional tools without removing the entire liner string, while preventing buckling of the liner by supporting it with the liner hanger and maintaining pressure in the annular chamber.
Implementation Method 1
maintaining pressure in an annular chamber
Implementation Method 2
supporting it with the liner hanger and maintaining pressure in the annular chamber
Data Source
AI summary
A method of drilling a well and installing a liner includes assembling concentric inner and outer strings of tubulars. A drill bit is located at the lower end of the inner string and a liner with a liner hanger makes up part of the outer string. The inner and outer strings may be rotated in unison to drill the well. At a selected depth, the operator sets the liner hanger and retrieves the inner string. The operator lowers a packer and a cement retainer on a string of conduit. The packer engages the liner hanger and the cement retainer is conveyed to the lower end of the liner. The cement retainer prevents cement in the outer annulus from flowing back up the string of conduit. The operator manipulates the conduit to set the packer.