Earth Boring Tool Fixed Blades Rotatable Cutting Structures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional earth-boring tools often experience core-outs, where cutting elements near the axial center wear out prematurely, leading to inconsistent drilling and increased maintenance costs, as they are not designed to evenly distribute wear across all cutting elements.
Innovation Solution
A hybrid earth-boring tool featuring both fixed blades and rotatable cutting structures, where the first rotatable cutting structure extends to the centerline and the second to the innermost boundary of the nose region, allowing for balanced wear distribution and reduced core-outs by incorporating blades that extend to the center, nose, shoulder, and gage regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional earth-boring tools are used with cutting elements distributed across the face, then drilling capability is provided, but cutting elements near the axial center wear out prematurely causing core-outs
Solution Approach 1:
The cutting structure is segmented into multiple zones: fixed blades extending to the centerline, first rotatable cutting structures on cones, and second rotatable cutting structures in the nose region. This segmentation allows each zone to perform specific functions and wear patterns, preventing core-outs by distributing cutting action away from the axial center.
Solution Approach 2:
Different regions of the tool have different cutting element configurations tailored to local requirements. The fixed blades with cutting elements at their leading edges handle central material, while rotatable cutting structures with circumferential rows of cutting elements handle peripheral material. This local differentiation ensures uniform wear distribution across all cutting elements.
2Area of stationary object
If cutting elements are distributed across the entire face including center, then complete coverage is achieved, but wear distribution becomes uneven with central elements wearing faster
Solution Approach 1:
The cutting structure is divided into fixed blades extending to the centerline and rotatable cutting structures on cones and nose. This segmentation creates distinct zones that prevent overlapping wear patterns and ensure uniform wear distribution across the entire cutting face.
Solution Approach 2:
Instead of having rotatable cutting structures at the center (which cause core-outs), the invention places fixed blades at the centerline and rotatable structures on the cones and nose. This inversion of the conventional arrangement reverses the wear pattern, preventing premature central element failure.
3Duration of action of moving object
If all cutting elements wear at similar rates, then lifespan is extended, but this requires a complex hybrid design with fixed blades and varying sized rotatable structures
Solution Approach 1:
The hybrid design integrates multiple cutting mechanisms (fixed blades and rotatable cutting structures) into a single tool that performs both drilling and reaming functions. This multi-functionality achieves uniform wear distribution while maintaining a unified tool structure that can handle various drilling conditions.
Solution Approach 2:
The tool incorporates both fixed and rotatable cutting structures that can adapt to different drilling conditions. The rotatable cutting structures on the cones and nose can rotate to distribute wear, while the fixed blades provide stable central cutting action, creating a dynamic system that optimizes wear distribution.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An earth-boring tool includes a body, a plurality of blades attached to the body and extending at least to a nose region of the earth-boring tool, a first rotatable cutting structure assembly coupled to the body, and a second rotatable cutting structure assembly coupled to the body. The first rotatable cutting structure assembly includes a first leg and a first rotatable cutting structure rotatably coupled to the first leg. A first cutting profile of the first rotatable cutting structure extends at least from a gage region of the earth-boring tool and at least partially through a cone region of the earth-boring tool. The second rotatable cutting structure assembly includes a second leg and a second rotatable cutting structure rotatably coupled to the second leg. A second cutting profile of the second rotatable cutting structure extends only from the gage region of the earth-boring tool and to an innermost boundary of a nose region of the earth-boring tool.