Subsea Pinning Machine Drill Bit Release Mechanism
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Solution Overview
Problem
Existing methods for removing tubular members from offshore drilling platforms, such as conductor assemblies, are inefficient and pose risks due to potential structural integrity issues from rust or damage, requiring a more convenient and versatile process to ensure safe removal without compromising the assembly's integrity.
Innovation Solution
A subsea pinning machine equipped with a drill bit release mechanism that drills through the tubular member and remains as a joining pin, utilizing a pair of jaws for gripping and hydraulic motors for operation, allowing for remote control and efficient pinning of the assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate pin insertion process is used after drilling, then the pin can be inserted to secure the assembly, but the operation becomes more complex and time-consuming with multiple steps
Solution Approach 1:
The drill bit is designed to serve dual functions: drilling the hole and then remaining in place as the pin to secure the assembly. This merging of the drilling tool and fastening element eliminates the need for separate pin insertion operations, reducing complexity while maintaining security.
Solution Approach 2:
The drill bit is designed to perform multiple functions throughout the operation sequence - first as a drilling tool to create the hole, then as a fastening pin to secure the tubular member assembly. This multi-functionality consolidates what would traditionally require two separate tools and operations.
2Productivity
If the drill bit is removed after drilling, then a separate pin can be inserted, but the process time and operational complexity increase
Solution Approach 1:
By combining the drilling function and pinning function into a single tool that remains in place, the operation eliminates the time required for tool removal and re-insertion, directly improving productivity while reducing total operation time.
Solution Approach 2:
The drill bit continues to serve a useful function after drilling by remaining as the securing pin. This continuous utilization of the tool eliminates idle time between operations and maintains productive action throughout the entire pinning process.
3Reliability
If traditional drilling and pinning methods are used, then the assembly can be secured, but the risk of failure during lifting increases due to potential rust or damage
Solution Approach 1:
The drill bit is positioned and secured in place before lifting operations begin, creating a pre-established secure connection point. This preliminary action ensures that the assembly is firmly pinned before any lifting stress is applied, preventing failure during the lifting process.
Solution Approach 2:
The drill bit serves as a pre-installed pin that provides structural support and security before lifting occurs. This beforehand securing action cushions against the potential harmful effects of rust and damage by establishing a reliable connection point that can withstand lifting stresses.
4Stability of the object's composition
If multiple strings are cemented together, then the assembly is stable, but removal becomes more difficult and time-consuming
Solution Approach 1:
The drill bit is positioned and secured through the cemented strings before removal operations begin. This preliminary pinning action creates a secure reference point that allows the assembly to be handled and removed more efficiently, overcoming the difficulty posed by the cemented connection.
Data Source
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AI summary
The present invention relates to a process for removing a tubular member extending downwards into a body of water, for example from a drilling platform. The tubular member may, for example, be a conductor assembly from an offshore drilling slot. The invention therefore also relates to a drilling slot recovery apparatus for use in such a process. A subsea pinning machine (1) for pinning together a tubular member assembly (4) that has an outer tubular casing (5) and one or more internal tubular casings (7), comprises a jaws (2) for gripping the outer casing (5), a drill bit (15), an actuator (20) for drilling through the assembly with the drill bit, and a release mechanism (40) for releasing the drill bit once this has drilled through the assembly so that the released drill bit serves in use to pin together the tubular casings forming the assembly.