Spider Tool Slips with Curved Support Surfaces
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Solution Overview
Problem
High-capacity spiders used in oil and gas exploration face limitations due to restricted central openings, which hinder the passage of larger diameter pipe collars and reduce workspace accessibility, leading to increased interference and safety risks during pipe handling operations.
Innovation Solution
A powered spider with outwardly curved and inwardly tapered slip support surfaces allows for radial outward movement of pipe gripping slips, expanding the central opening and accommodating larger pipe sizes, while maintaining a low elevation profile to enhance workspace accessibility and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a high capacity spider is used to handle larger pipe strings, then the pipe gripping capacity is improved, but the central opening size is reduced due to larger slips, limiting the passage of pipe collars
Solution Approach 1:
The slip support surface is designed with a curved profile that allows the slips to move radially outward when in the gripping position, dynamically changing the central opening size from a restricted state during pipe handling to an expanded state for pipe collar passage
Solution Approach 2:
The invention adds radial movement capability to the traditional vertical slip movement, allowing slips to move in both vertical and radial directions. This dimensional addition enables the slips to clear from the central opening path while maintaining gripping capability on the pipe
2Ease of operation
If the spider elevation profile is kept low to improve workspace accessibility, then worker safety and convenience are improved, but the pipe gripping capacity is reduced
Solution Approach 1:
The curved slip support surface enables the slips to dynamically adjust their radial position, allowing a compact low-profile structure to achieve high gripping capacity when needed while maintaining workspace accessibility during normal operations
3Force
If larger slips are used to increase pipe gripping capacity, then the ability to handle heavier pipe strings is improved, but the interference with pipe handling equipment and worker safety are worsened
Solution Approach 1:
The slips dynamically change their radial position based on operational needs - moving outward to clear the central opening for tong operations and worker access, and moving inward to engage the pipe for gripping, thereby eliminating interference while maintaining high capacity
Solution Approach 2:
The harmful interference effect is eliminated by extracting the slips from the central opening path through radial outward movement, separating the gripping function from the pipe collar passage path
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 solution enables the spider to handle wider pipe sizes and accessories without opening the rotary table, reducing interference and injury risks by increasing the unobstructed central opening width, allowing for safer and more efficient pipe handling operations.
Implementation Method 1
The slips are slidably attached to the slip carrier plates by the slip support surfaces and slip slide surfaces so that each pipe gripping slip will be slidably supported on its corresponding slip carrier plates
Data Source
AI summary
A pipe gripping apparatus is disclosed having a plurality slips slidably mounted on corresponding slip support surfaces disposed radially the vertical axis of a central opening. The slip support surfaces include an upper region having a radially outwardly curved surface and a lower region having a flat inwardly tapered surface with respect to the vertical axis of the central opening. Powered actuators and a timing ring pivotally linked to the slips move the slips towards and away from each other along their corresponding slip support surfaces to engage and release a pipe. Move of the slips fully upward and outward along outwardly curved slip support surfaces will substantially remove the slips from the central opening to prevent obstruction of the central opening by the slips.