Hybrid Rotary-Plasma Drill Bit for Hard Rock Tensile Fracture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current drill bit assemblies are inefficient in fracturing rock formations, as they rely on compressive failure and do not effectively utilize the natural tensile failure of rock, leading to slower drilling rates in hard rock formations.
Innovation Solution
A hybrid rotary-plasma drill bit assembly that combines rotary action with high voltage plasma discharges, using multiple electrodes to apply electrical discharge across the circumferential surface of a rock core, causing tensile failure and increasing the efficiency of rock fracture and removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If mechanical cutters are used to drill hard rock formations, then the drill bit can physically cut the rock, but the drilling rate is slow due to reliance on compressive failure
Solution Approach 1:
The patent combines mechanical cutters with electrical discharge electrodes in a hybrid drill bit assembly. The mechanical cutters perform initial rock cutting while the electrodes apply electrical discharge to fracture the rock core through tensile failure. This merging of mechanical and electrical systems resolves the contradiction by achieving faster drilling rates through combined action while distributing the complexity across multiple functional components rather than relying on a single complex mechanism
Solution Approach 2:
The patent replaces purely mechanical compression-based rock fracture with electrical discharge-induced tensile failure. The electrical discharge system substitutes for additional mechanical cutting forces, achieving rock fracture through a different physical mechanism (electrical plasma discharge) that exploits rock's tensile weakness rather than relying solely on mechanical compression, thereby improving drilling rate without proportionally increasing mechanical system complexity
2Productivity
If electrical discharge is applied to fracture rock core, then tensile failure is utilized for faster drilling, but the device complexity increases with multiple electrodes
Solution Approach 1:
The drill bit assembly is designed with multi-functionality, where the same electrode system serves multiple purposes: fracturing the rock core through tensile failure, and the hollow portion serves both as a structural element and as a channel for drilling mud flow to remove rock cuttings. This multi-functionality reduces the need for separate dedicated components, thereby limiting the increase in device complexity while maintaining high rate of penetration
Solution Approach 2:
The electrode system is segmented into multiple electrodes positioned at different locations around the hollow portion. This segmentation allows the electrical discharge to be applied at multiple points simultaneously or sequentially, improving the efficiency of rock core fracture and rate of penetration. The segmented approach distributes the functional load across multiple simpler electrode elements rather than requiring a single complex electrode structure
3Productivity
If rock core is removed through hollow portion, then drilling efficiency is improved, but the hollow portion requires additional structural complexity
Solution Approach 1:
The hollow portion of the drill bit serves multiple functions simultaneously: it provides the structural framework for mounting the electrodes, acts as a channel for drilling mud flow to remove rock cuttings, and defines the working space for electrical discharge application. This multi-functionality eliminates the need for separate dedicated structures for each function, thereby improving rock removal efficiency without proportionally increasing device complexity
Solution Approach 2:
The patent merges the structural support function, electrode mounting function, and rock cutting debris removal function into a single integrated hollow portion structure. The hollow portion combines these functions that would traditionally require separate components, achieving efficient rock core removal while minimizing the increase in overall device complexity through functional integration
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
This approach enhances the rate of penetration in hard rock formations by utilizing tensile failure, resulting in faster drilling rates and more efficient removal of rock cuttings, while also allowing for the use of mechanical cutters to assist in rock core extraction.
Implementation Method 1
Electrical discharge is applied across multiple locations on the circumferential surface of the rock core to fracture the rock core
Implementation Method 2
A hybrid rotary-plasma drill bit assembly that combines rotary action with high voltage plasma discharges
Data Source
AI summary
A rock formation drill bit assembly with electrodes includes a drill bit including a hollow portion that extends along a longitudinal axis of the drill bit. The hollow portion extends from a first end to a second end opposing the first end. Cutters as positioned on the first end. The cutters are configured to cut the rock formation resulting in a rock core protruding from the rock formation into the hollow portion. The rock core includes a circumferential surface. Multiple electrodes are positioned within an inner circumferential surface of the hollow portion. The multiple electrodes are configured to apply electrical discharge across multiple locations on the circumferential surface of the rock core. The electrical discharge causes the rock core to fracture.