Mechanical Percussive Hammer Drill Bit Impact
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Solution Overview
Problem
Traditional downhole drilling methods face reduced rate of penetration due to increased formation rock strength and mechanical limitations, especially when drilling through cement plugs or using wireline or coiled tubing systems, which can lead to high drill bit wear and stick-slip conditions.
Innovation Solution
A mechanical percussive hammer assembly that applies repetitive axial impact forces to a drill bit using a driveshaft, hammer, and anvil with cammed control surfaces, allowing for adjustable impact frequency and force, reducing the need for complex hydraulic systems and improving rock cutting efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional rotating drill bits are used for drilling, then weak materials can be sheared and removed effectively, but rate of penetration decreases when drilling through hard formation rock or cement plugs
Solution Approach 1:
The patent employs periodic impact forces through a mechanical hammer assembly that delivers repeated axial blows to the drill bit. The hammer mechanism includes a hammer body, anvil with cam surface, and spring-loaded components that create periodic impact cycles, transforming continuous rotation into pulsed percussive action to break hard rock and cement plugs effectively
Solution Approach 2:
The patent replaces complex hydraulic impact systems with a purely mechanical hammer assembly driven by rotational motion. The mechanical conversion from rotation to impact is achieved through cam surfaces, follower arms, and spring-loaded hammers, eliminating the need for hydraulic valves, pistons, and fluid pressure systems while maintaining effective impact force delivery
2Force
If hydraulic impact tools with valves and pistons are used, then axial impact forces can be generated, but device complexity increases and adaptability to wireline or coiled tubing systems is reduced
Solution Approach 1:
The patent substitutes hydraulic mechanisms with a mechanical impact generation system. The hammer assembly converts rotational motion from the driveshaft into axial impact forces through cam-follower-hammer mechanics, eliminating complex hydraulic valves, pistons, and fluid pressure control systems while delivering effective percussive force to the drill bit
Solution Approach 2:
The mechanical hammer assembly is self-actuating through the rotational motion of the driveshaft. The cam surfaces automatically convert rotation into hammer activation without requiring external hydraulic control systems, making the impact tool adaptable to various conveyance systems including wireline and coiled tubing where complex hydraulic control is impractical
3Productivity
If high rock cutting force is applied to increase penetration rate, then drilling speed improves, but drill bit wear and breakage increase
Solution Approach 1:
The periodic impact delivery allows high force application in short pulses followed by recovery periods. The hammer strikes the drill bit in repeated cycles, delivering high impact forces to fracture rock while the intervals between impacts allow stress dissipation and prevent continuous overload on the drill bit structure, reducing cumulative wear and breakage risk
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 enhances the rate of penetration by reducing cutting force, lowering drill bit wear, minimizing stick-slip occurrences, and increasing tool life, while being adaptable for various drilling operations and conveyance systems.
Implementation Method 1
an anvil with a cammed control surface, wherein rotation of the driveshaft is operable to rotate the hammer along the control surface and the cam is operable to axially move the hammer with respect to the driveshaft
Data Source
AI summary
A modular, mechanical percussive hammer assembly may be used with drill strings, wireline cable, and coiled tubing. Rotation of a splined driveshaft by downhole electric, hydraulic or mud motor rotates a downwardly-biased hammer and drill body rotatively captured within a upwardly-biased stationary anvil. A bit is carried by the drill body. The hammer contacts and rotates along a cammed control surface of the anvil as the driveshaft is rotated. Interaction between the cammed control surface and the hammer operated to create an axial impact force that is transmitted to the drill body and drill bit.