Underreamer Drill Hammer Radial Bit Adaptation
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Solution Overview
Problem
Existing methods for installing large diameter casings are expensive and require specialized, non-reusable drill bits and drive shoes, leading to high costs and long lead times.
Innovation Solution
A low-profile underreamer drill hammer with a percussive drill bit that moves between radially retracted and extended positions, allowing for efficient advancement of casing through soil and rock without the need for special drill bits or drive shoes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If specialized large diameter drill bits and drive shoes are used to advance casing, then the casing can be installed, but the cost increases and lead time extends due to non-reusability and susceptibility to wear
Solution Approach 1:
The drill bit is designed to perform multiple functions: it can advance the casing through soil and overburden, then retract to drill a smaller diameter hole in bedrock for anchoring. This multi-functionality eliminates the need for separate specialized drill bits and drive shoes, reducing overall system complexity while maintaining installation reliability
Solution Approach 2:
The drill bit incorporates a movable cutting element that can transition between extended and retracted positions. This dynamic configuration allows the same drill bit to adapt to different drilling conditions (soil vs. rock), eliminating the need for multiple static specialized bits and reducing device complexity
2Ease of manufacture
If reusable drill bits are used to reduce cost, then the cost decreases, but the drill bit must be able to adapt to different drilling conditions which increases complexity
Solution Approach 1:
The drill bit uses a movable cutting element that can be positioned dynamically - extended for soil/overburden drilling and retracted for rock drilling. This single adaptable component replaces multiple specialized bits, reducing manufacturing costs while maintaining the ability to handle different drilling conditions
Solution Approach 2:
The drill bit features an asymmetric design where the cutting element can be positioned at different radial distances from the center. This asymmetric positioning capability allows the same bit to create different effective diameters for different ground conditions, providing versatility without requiring multiple symmetric specialized bits
3Volume of moving object
If the drill bit remains extended to drill larger diameter holes, then larger holes can be drilled, but the drill bit experiences increased wear when drilling rock
Solution Approach 1:
The cutting element can be dynamically retracted during rock drilling operations. This reduces the effective diameter of the drill bit when drilling rock, minimizing wear on the cutting elements while still allowing the drill bit to advance through the rock for anchoring purposes
Solution Approach 2:
The drill bit applies different effective diameters to different drilling conditions: full extended diameter for soil/overburden where large hole volume is needed, and reduced retracted diameter for rock where minimizing wear is critical. This local adaptation of drilling parameters optimizes both hole volume and drill bit durability
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 system enables cost-effective and efficient installation of large diameter casings by allowing the drill bit to adapt its diameter for different drilling conditions, reducing wear and increasing the reusability of the drill hammer.
Implementation Method 1
a percussive drill hammer housed within the housing, the percussive drill hammer having a drill bit movable between a radially retracted position and a radially extended position
Data Source
AI summary
An underreamer drill hammer comprising a canister including a housing having an outer diameter, a proximal end configured for attachment to a drill string, and a percussive drill hammer housed within the housing, the percussive drill hammer having a drill bit movable between a radially retracted position and a radially extended position. The drill bit can rotate and is designed in a manner that the drill bit head cams, pivots, or swings out to a larger cutting diameter when the system is rotated in a first direction. The system is rotated in a second direction to retract the bit heads. The bits are retracted to remove the canister from the casing or to drill a smaller diameter hole through rock.