Downhole Drilling Accelerator for Percussive Motion Conversion
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Solution Overview
Problem
Existing downhole drilling technologies face challenges in efficiently converting rotational drive into percussive motion at the drill bit, leading to increased torque on tubular connections and reduced drilling efficiency.
Innovation Solution
A drilling accelerator that mechanically converts rotational drive into axially directed percussive motion using a housing with a drive connection, a rotational to axial mechanical drive converter, and a longitudinally moveable drive shaft, which applies percussive force to the drill bit, thereby enhancing drilling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If rotational drive is directly applied to the drill bit, then the drill bit can rotate and drill, but the drilling penetration rate is low and high torque is generated on tubular connections
Solution Approach 1:
The patent replaces the conventional direct rotational mechanical drive system with a hybrid system that incorporates a percussive mechanism. The rotational motion from the drive shaft is converted into axial percussive motion through a mechanical converter (such as a cam-follower mechanism or eccentric mechanism), which substitutes part of the rotational drilling action with impact-driven penetration, thereby reducing torque requirements and increasing penetration rate.
Solution Approach 2:
The patent introduces dynamic percussive motion to the traditionally static or uniformly rotational drilling process. By superimposing axial impact forces on the rotational motion of the drill bit, the system creates a dynamic drilling action that alternates between cutting and impact, enhancing rock fracture efficiency and reducing the torque needed to maintain drilling progress.
2Productivity
If weight on bit is increased to improve penetration rate, then drilling efficiency increases, but the required equipment strength and tubular connection load increase
Solution Approach 1:
The percussive mechanism delivers preliminary impact forces to the rock formation before the rotational cutting action fully engages. These pre-applied axial impacts create initial fractures and loosen the rock structure, reducing the subsequent weight on bit needed to achieve continued penetration, thereby lowering the overall strength requirements for drilling equipment.
Solution Approach 2:
The drilling system employs periodic percussive impacts rather than continuous static weight application. The rhythmic delivery of axial impact forces allows the rock formation to respond to each blow, creating cumulative fracture effects over time. This periodic action achieves high penetration rates without requiring sustained high weight on bit, reducing peak load requirements on equipment and tubular connections.
Data Source
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AI summary
A drilling accelerator that is driven from a rotational drive to generate a percussive axial motion on a drill bit. The drilling accelerator includes a drive connection to mechanically convert rotational drive to axially directed percussive motion. A wellbore tubular connection is also disclosed that transitions torque to resist back off when left hand or right hand torque is applied.