Pilot Bit Cam and Rolling Element Layout for Lower Wear Boring

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Solution Overview

Problem

Existing drill bits face challenges in efficiently and economically drilling straight, deviated, and horizontal wells, as they often experience wear and tear due to direct impacts and friction, leading to reduced drilling efficiency and increased operational costs.

Innovation Solution

The development of a drill bit apparatus featuring a rotating segment with a first radial surface and a non-rotating segment, connected by rolling elements that transfer axial movement, allowing for a percussive force to be delivered through cam surfaces, reducing direct impact and enhancing drilling efficiency by distributing the force through spherical rolling elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional drill bits are used for boring wells, then drilling can be performed, but wear and tear increases due to direct impacts and friction

Engineering Contradiction:

Improvedrill bit longevityVSAvoidwear and tear from direct impact

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Rolling elements are introduced as intermediary components between the rotating segment and non-rotating segment. These rolling elements convert direct impact forces into rolling motion, mediating the force transmission and eliminating direct contact wear between the drill bit and formation, thereby resolving the contradiction between drilling effectiveness and wear reduction

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the traditional direct mechanical impact system with a rolling element mechanism. Instead of direct hammering action, the system uses rolling elements to transfer axial movement from rotation, substituting high-friction direct contact mechanics with low-friction rolling mechanics, thus reducing wear and tear

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If rolling elements are added to transfer axial movement, then wear is reduced, but device complexity increases

Engineering Contradiction:

Improvedrill bit longevityVSAvoidstructure with rolling elements

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The rolling elements are integrated within the housing structure, merging the force transmission function with the structural support function. The housing simultaneously provides structural integrity and contains the rolling elements, combining multiple functions into unified components to minimize the increase in device complexity

Inventive Principle:

Principle #5Merging (Combining)

3Object-affected harmful factors

If spherical rolling elements are used to distribute force, then direct impact is reduced, but manufacturing precision requirements increase

Engineering Contradiction:

Improvedirect impact forceVSAvoidspherical rolling element tolerance

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent specifies optimal parameter ranges for the spherical rolling elements, including diameter ratios (each rolling element diameter equals one-half of the housing inner diameter) and contact surface geometries (tapered sections with undulating waveform profiles). By defining these parameters within acceptable tolerances, the system achieves effective force distribution without requiring extreme manufacturing precision

Inventive Principle:

Principle #35Parameter changes

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 design enhances drilling efficiency by reducing wear on the drill bits, increasing the longevity of the equipment, and improving the ability to drill complex well trajectories with reduced operational costs through the distribution of force and reduced direct impact.

Implementation Method 1

one or more rolling elements disposed between and in contact with the first and second radial surfaces for transferring the non-rotating segment in an axial direction upon rotation of the rotating segment

Methodology Applied

Scientific EffectRolling contact: Ball Bearing

Implementation Method 2

allowing for a percussive force to be delivered through cam surfaces

Methodology Applied

Scientific EffectCam mechanism: Cam

Data Source

PatentUS11136828B2Boring apparatus and method

Publication Date: 2021.10.05 STABIL DRILL TECHNOLOGIES LLC

AI summary

An apparatus for boring a wellbore, including a bit body having a first end, an inner cavity, and a second end. The first end is connected to a workstring that is configured to deliver a rotational force to the bit body. The inner cavity contains a profile having a first radial cam surface. The second end includes a working face containing a cutting member. The apparatus also includes a pilot bit rotatively connected within the inner cavity. A second radial cam surface is contained on a first end of the pilot bit. The first and second radial cam surfaces are operatively configured to deliver a hammering force. A second end of the pilot bit may include an engaging surface configured to engage a formation surrounding the wellbore. The bit body rotates relative to the pilot bit.