Split Casing String Mudline Suspension System
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Solution Overview
Problem
Existing mudline suspension systems are often rated for lower subsurface pressures than required in certain applications, leading to the need for more robust solutions that can handle greater mechanical loads without increasing costs.
Innovation Solution
The implementation of a split casing string system where a downhole liner portion is hung from a lower end of the casing string below the mudline suspension hanger profile, and an uphole tieback portion is sealed to the downhole liner and passes upwardly through the mudline suspension hanger profile, bypassing it and being supported from a wellhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a standard mudline suspension system is used, then the system is cost-effective and easy to install, but it cannot handle greater subsurface pressures than its rating
Solution Approach 1:
The casing string is divided into two functional segments: a downhole liner portion that remains hung from the mudline suspension hanger profile, and an uphole tieback portion that is sealed to the liner and passes upwardly through the hanger profile to be supported from the wellhead. This segmentation allows the system to bypass the pressure limitation of the original mudline suspension system while maintaining the simplicity of the overall configuration.
2Stress or pressure
If the mudline suspension system is rated for higher pressures, then it can handle greater subsurface pressures, but the cost increases
Solution Approach 1:
The mudline suspension hanger profile serves multiple functions: it continues to support the downhole liner portion for standard operations, while simultaneously allowing the uphole tieback portion to pass through and be supported from the wellhead for high-pressure applications. This multi-functionality enables the system to achieve 10,000 psi pressure rating without replacing the entire suspension system, thereby avoiding increased manufacturing costs.
3Stress or pressure
If a split casing string system is implemented, then the pressure rating increases from 5,000 psi to 10,000 psi, but the system complexity increases
Solution Approach 1:
The uphole tieback portion is sealed to the downhole liner portion and nested within the mudline suspension hanger profile. The tieback portion passes upwardly through the hanger profile and is supported from the wellhead, creating a nested configuration that achieves high-pressure capability while maintaining a compact and manageable system structure.
Data Source
AI summary
A wellbore system includes a mudline suspension system arranged to provide a pressure rating sufficient for performing operations within a wellbore. The wellbore system includes a conductor pipe installed through a subaquatic surface location, and at least one casing string hung from an interior of the conductor pipe into the wellbore. A split casing string extends through the at least one casing string, includes a downhole liner portion hung from a lower end of the at least one casing string and an uphole tieback portion sealed to an interior surface of the lower liner portion. A wellhead supports the split casing string, wherein the upper tieback portion of the split casing string is hung from the wellhead.