Seated Hammer Core Sampling with Impact Decoupling
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Solution Overview
Problem
Current core sampling methods are expensive, slow, and inefficient, particularly when dealing with hard rock formations, as they require high-speed drill rigs and fragile diamond impregnated bits that are prone to damage, and existing impact mechanisms fail to deliver sufficient force or protect the core sample from mechanical damage.
Innovation Solution
A core sampling apparatus with a rotatable tubular housing and a core taking bit that can move axially, combined with a retrievable hammer assembly that provides impact along a longitudinal path decoupled from the core catcher barrel, allowing for efficient core sampling through any formation while protecting the core from rotation and impact forces, using a magnetic or fluid-driven hammer mechanism that isolates the core from damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-speed rotation and diamond impregnated bits are used for core sampling, then penetration speed is improved, but the cost increases and the bits become fragile and prone to damage
Solution Approach 1:
The patent replaces the traditional high-speed rotational mechanical cutting system with a percussive impact system. The core bit is subjected to repeated impact forces from a hammer mechanism rather than continuous high-speed rotation, which reduces the fragility and cost of the cutting elements while maintaining penetration capability into hard rock formations.
Solution Approach 2:
The patent changes the operational parameters from high rotational speed to controlled impact frequency and force. By varying the impact parameters and decoupling them from core rotation, the system achieves effective penetration without the need for expensive, fragile diamond-impregnated bits operating at high speeds.
2Force
If impact force is applied to advance the core sampling barrel, then penetration capability is improved, but the core sample becomes damaged by axial impact movement
Solution Approach 1:
The patent segments the impact force application from the core sample. The hammer mechanism applies impact force to the core bit through an impact transfer tube, while the core catcher barrel and its contents remain isolated from these axial impact movements. This segmentation allows high impact forces for penetration without transmitting damaging forces to the core sample.
Solution Approach 2:
The patent introduces an intermediary impact transfer tube that transmits impact forces from the hammer to the core bit while isolating the core catcher barrel. This intermediary component acts as a mechanical decoupler, allowing the core to be advanced into the barrel without being subjected to the harmful axial impact movements.
3Force
If the hammer is locked to the outer casing during impact, then impact force delivery is improved, but the outer casing experiences excessive stress and limited working life
Solution Approach 1:
The patent introduces an impact transfer tube as an intermediary component between the hammer and the outer casing. This tube absorbs and directs the impact forces to the core bit while preventing these forces from being transmitted to the outer casing, thereby reducing casing stress and extending working life while maintaining effective impact force delivery.
4Reliability
If slow rotation is used with durable bits, then cost and durability are improved, but penetration speed into hard rock formations decreases
Solution Approach 1:
The patent substitutes the high-speed rotational cutting mechanism with a percussive impact mechanism. This allows the use of durable, less expensive bits that operate at slow rotation speeds while achieving effective penetration into hard rock formations through repeated impact forces, thereby resolving the contradiction between durability and penetration speed.
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
Enables faster, cost-effective core sampling across various formations without damaging the core samples, using durable bits that require slow rotation and minimizing stress on the drill casing, allowing for efficient penetration and retrieval of high-quality core samples.
Implementation Method 1
using a magnetic or fluid-driven hammer mechanism
Implementation Method 2
using a magnetic or fluid-driven hammer mechanism
Data Source
Figure 1A
Figure 1B~1C
Figure 1D
AI summary
A retrievable core sampling assembly for latching to or relative to a rotatable tubular housing 1 of a core sampling apparatus to allow the capture and retrieval of a core 19 from a subterranean formation, the assembly comprising or including: a core catcher barrel 18 for a core 19, the barrel 18 being rotationally isolated from the tubular housing 1 and cooperable with a core taking bit 2 coupled to the rotatable tubular housing 1 to retain a core 19, and a hammer 100 for providing impact to the core taking bit 2 along a longitudinal impact path that is or is substantially decoupled from the core catcher barrel 8 so that when latched, rotation and impact of the core taking bit 2 captures and passes core material from the formation to the core catcher barrel 2 in manner that isolates a core 10 9 in the core catcher barrel 18 from rotation and impact forces.