Recessed Gage Cutting Elements for Cased-Hole Bit Debris Removal

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Tools for cased-hole operations face challenges in disintegrating structures without damaging the existing casing, as they often become stuck due to lack of cutting elements at the gage or inner diameter, necessitating a solution that minimizes cutting into the casing while effectively removing equipment.

Innovation Solution

The development of a cased-hole bit with gage inserts made of hardmetal or superhard materials, featuring a recessed cutting edge that extends to the nominal diameter, minimizing engagement with the casing while effectively cutting through debris between inserts and the wellbore sidewall.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If cutting elements are added at the gage or inner diameter to enable effective cutting of debris, then cutting effectiveness is improved, but the risk of casing damage increases

Engineering Contradiction:

Improvecutting effectivenessVSAvoidcasing damage risk

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The cutting elements are designed with non-uniform exposure around the gage circumference, creating zones of different cutting aggressiveness. This allows effective cutting in some areas while minimizing casing engagement in others, resolving the contradiction between cutting effectiveness and casing protection.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The cutting elements are configured to dynamically adjust their engagement with the casing based on operating conditions such as lateral forces and rotation speed. This dynamic behavior allows the system to maintain cutting effectiveness when needed while automatically reducing casing engagement to prevent damage.

Inventive Principle:

Principle #15Dynamics

2Object-affected harmful factors

If cutting elements are recessed to minimize casing engagement, then casing protection is improved, but the ability to cut through debris effectively deteriorates

Engineering Contradiction:

Improvecasing protectionVSAvoiddebris cutting ability

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

Different portions of the cutting element array have different recess depths and exposure levels. This local variation allows some cutting elements to protect the casing while others effectively cut debris, simultaneously achieving both casing protection and effective debris removal.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The gage cutting structure is segmented into multiple discrete cutting elements with different functions. Some elements are optimized for debris cutting while others are positioned or shaped to minimize casing engagement, allowing the system to perform multiple functions simultaneously.

Inventive Principle:

Principle #1Segmentation

3Productivity

If cutting elements are positioned to extend to nominal diameter for effective cutting, then cutting performance is improved, but the likelihood of large cuttings becoming wedged and causing sticking increases

Engineering Contradiction:

Improvecutting performanceVSAvoidsticking prevention

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The cutting elements are positioned asymmetrically relative to the nominal diameter, with intentional gaps and varied radial positions. This asymmetric configuration prevents large cuttings from becoming wedged between symmetrically positioned elements, reducing the risk of sticking while maintaining cutting performance.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The cutting elements extend slightly beyond what would be minimally required for effective cutting, creating intentional clearance zones. This partial over-extension prevents cutting elements from binding against each other or the casing, eliminating the excessive action that would cause sticking.

Inventive Principle:

Principle #16Partial or excessive action

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 solution allows for efficient disintegration of structures in cased wellbores without damaging the casing, ensuring the bit or tool can rotate freely and remove metallic and elastomeric cuttings effectively, preventing sticking issues.

Implementation Method 1

cutting elements made of hardmetal or superhard materials, featuring a recessed cutting edge that extends to the nominal diameter, minimizing engagement with the casing while effectively cutting through debris

Methodology Applied

Scientific EffectAbrasion: Abrasion

Implementation Method 2

efficient disintegration of structures in cased wellbores without damaging the casing

Methodology Applied

Scientific EffectImpact force: Impact Force

Data Source

PatentUS11208848B1Cutting element for casing bit

Publication Date: 2021.12.28 KLEAR BIT TECHNOLOGIES LLC

AI summary

A downhole tool, or earth-boring bit, for use in disintegrating structures in a cased wellbore includes a tool body having a central axis about which the tool body rotates and an outermost gage surface on the tool body. At least one gage cutting element on the gage surface has a blunt outermost projection and a sharp cutting edge recessed from the blunt outermost projection, wherein, during rotation of the tool body, the blunt outermost surface contacts the cased wellbore and the sharp cutting edge does not. The blunt outermost projection may be on a leading element while the sharp cutting edge is on a separate, trailing element.