Wireline Coring Recovery System with Anti-Stuck Catcher
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Solution Overview
Problem
Existing wireline coring recovery systems for seafloor drilling rigs face issues with stuck core barrels due to inappropriate drilling processes or fluid circulation failures, leading to broken ropes and contamination of core samples, and require complex structures and auxiliary devices for recovery, increasing operation costs and risks.
Innovation Solution
A wireline coring recovery system with a simple and compact structure featuring a catcher with an anti-stuck mechanism, submersible tension sensor, and flushing water system, allowing for easy recovery and release of the inner core barrel by utilizing self-weight and rotational mechanisms to clamp and release the spearhead, and real-time tension monitoring to prevent jamming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the catcher continues to clamp the spearhead by force to recover the core barrel, then the core barrel can be recovered, but the rope will break causing failure of the whole coring process
Solution Approach 1:
The catcher is designed with a dynamic clamping mechanism that can transition between clamping and releasing states. The compression spring enables the catcher to automatically release the spearhead when excessive force is applied, preventing rope breakage while maintaining recovery capability through controlled dynamic response.
Solution Approach 2:
The compression spring acts as a cushioning element that absorbs excess clamping force before it can damage the rope. When the core barrel is stuck, the spring compresses to provide a controlled release force, preventing the rope from breaking under excessive tension.
2Reliability
If a sludge pump and auxiliary devices are used to recover the core barrel, then the core barrel can be recovered, but the operation cost increases and the structure becomes complex
Solution Approach 1:
The catcher is designed as a self-service recovery device that uses its own weight and the compression spring mechanism to recover the core barrel without requiring external sludge pumps or auxiliary devices. The system leverages the self-weight of the catcher and the elastic energy stored in the spring to achieve recovery, significantly simplifying the overall system structure.
Solution Approach 2:
The invention extracts and eliminates the need for complex auxiliary devices like sludge pumps from the recovery system. By using only the catcher's own components (weight rod, compression spring, steel balls) and the rope mechanism, the system achieves core barrel recovery without requiring additional auxiliary equipment, thereby reducing structural complexity.
3Reliability
If the catcher is used to clamp the spearhead for recovery, then the core barrel can be recovered, but residue sludge enters the core barrel contaminating core samples
Solution Approach 1:
The invention extracts the harmful sludge removal function from the recovery process by designing a system that does not rely on sludge pumps or fluid circulation. The recovery mechanism uses mechanical components (catcher, compression spring, steel balls) that do not introduce sludge into the core barrel, thereby eliminating the contamination source while maintaining recovery capability.
Solution Approach 2:
The system uses simple, clean mechanical components that can be easily disposed of or replaced if contaminated. The steel balls and compression spring are simple elements that do not retain sludge, unlike complex pump systems. This approach minimizes the risk of sludge contamination in core samples while maintaining effective recovery functionality.
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
The system effectively prevents core barrel sticking, reduces operation costs, ensures clean core samples, and facilitates easy manipulation by converting between interlocking and unlocking modes to recover or release the core barrel, enabling efficient restart of drilling operations.
Implementation Method 1
A compression spring is provided between the compression spring seat and a top of the annular column; a plurality of steel ball holes are provided at a side wall of the annular column; each steel ball hole is provided with one steel ball; a downward movement of the rotatable ferrule forces the steel balls to move towards a center of the annular column and then snap into an annular groove of a spearhead of an inner core barrel
Implementation Method 2
the catcher comprises an anti-stuck mechanism, a weight rod, a compression rod, a fixed guide tube, a rotatable ferrule, a compression spring, a steel ball seat and a plurality of steel balls
Data Source
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AI summary
There is provided a wireline coring recovery system of a seafloor drilling rig, including: a winch, a rope, a submersible tension sensor, a cover, a main shaft and a catcher. One end of the rope is wound on the winch, and the other end of the rope is connected to an upper end of the catcher after the rope passes over a first pulley provided below the submersible tension sensor and then through a tapered hole on the cover. The catcher is provided in a center hole of the main shaft. The present application further provides a method of using the wireline coring recovery system. By the cooperation of the compression rod skewed teeth, the first rotating core skewed teeth, the second rotating core skewed teeth and the compression spring, the inner core barrel is readily recovered or released.