External Tool Trap with Crush Cylinders for Drill String Impact
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Solution Overview
Problem
Conventional internal tool traps fail to cushion the impact of falling drill strings and are ineffective when the string is lowered below the trap's position, posing safety risks to oilfield workers and equipment.
Innovation Solution
An external tool trap assembly with a collar clamp, energy-absorbing crush cylinders, and a catcher plate assembly that can be attached to the outside of a lubricator or tool string housing, featuring a funnel receptacle to catch and absorb the kinetic energy of falling equipment, preventing damage and injury.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an internal tool trap is used to catch falling drill strings, then the tool string can be caught, but the impact cannot be cushioned and the trap becomes ineffective when the string is lowered below the trap position
Solution Approach 1:
The invention moves the trap from an internal position within the housing to an external position below the housing. This dimensional relocation allows the trap to function effectively for both caught strings and lowered strings, resolving the limitation where internal traps become ineffective when strings are lowered below trap position.
Solution Approach 2:
The invention incorporates energy-absorbing crush cylinders that deform during impact to cushion the falling tool string. This beforehand cushioning mechanism absorbs the kinetic energy of the falling string, preventing damage to both the string and surrounding equipment.
2Device complexity
If an internal tool trap is used, then the structure is compact, but it cannot prevent damage from unintended release and is ineffective when string is lowered below trap
Solution Approach 1:
Relocating the trap externally below the housing improves safety reliability by ensuring the trap remains effective regardless of string position during lowering operations, while maintaining reasonable structural complexity through the use of standard mechanical components.
Solution Approach 2:
The crush cylinders provide beforehand cushioning by being pre-positioned to absorb impact energy, significantly improving safety protection reliability without adding excessive structural complexity.
3Ease of manufacture
If the trap mechanism is positioned inside the housing, then installation is simple, but it poses safety risks to workers and equipment
Solution Approach 1:
The external positioning of the trap below the housing reduces safety risks to workers and equipment by placing the catch mechanism outside the confined housing space, while the clamp assembly maintains easy installation through straightforward attachment to the housing exterior.
Solution Approach 2:
The crush cylinders provide beforehand cushioning that significantly reduces safety risks by absorbing impact energy before it can reach workers or surrounding equipment, while maintaining ease of installation through modular design.
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 external tool trap effectively cushions and catches unintentionally released drill strings, minimizing damage to tools and equipment while ensuring worker safety by dissipating kinetic energy through crush cylinders, allowing for safe lowering and raising of drill strings during operations.
Implementation Method 1
energy-absorbing crush cylinders... first and second energy absorbing crush cylinders are affixed to corresponding bottom ends of the first and second vertical rails... dissipating kinetic energy through crush cylinders
Implementation Method 2
cushions the impact of falling drill strings... catch and absorb the kinetic energy of falling equipment
Data Source
AI summary
An improved external trap apparatus 570 and a method for safely controlling drilling tool string components during oil field drilling operations includes a collar clamp 72 affixed to a drilling tool string lubricator 80 and configured with laterally spaced first and second vertical rails 120, 122 depending therefrom. Lubricator 80 also carries a lubricator clamp assembly 572 which is affixed to Lubricator 80 with inward clamping surfaces defining a non-circular or slightly elliptical central bore 574. Laterally spaced first and second vertical rails 120, 122 are configured to support a reinforced catcher plate assembly 164 carrying a tool-end receiving funnel receptacle 202 and first and second energy absorbing crush cylinders 160, 162. When the drill string 82 is raised or withdrawn from the well 28, the funnel receptacle 202 can be rotated into coaxial alignment to catch the drill string's end or downhole tool, in the event of an inadvertent loss of control of the drill string 82.