Stabilizer Assembly Axial Load Path Redirection

Solution Overview

Problem

Existing stabilizer assemblies in drill strings experience mechanical compromise and early failure due to axial loads and forces, which accelerate wear and damage at the interlocking features between the sleeve and collar, leading to catastrophic failures.

Innovation Solution

A stabilizer assembly design featuring a tubular member with a first castellated portion and a stabilizer sleeve with a second castellated portion, along with shoulders defining an annular space, where a key is inserted to redirect the axial load path through the shoulders and keys instead of the castellated portions, reducing wear and damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If interlocking features (castellated portions) are used to maintain axial and rotational position between sleeve and collar, then positional stability is improved, but wear and damage accelerate due to high cyclic loading

Engineering Contradiction:

Improvepositional stabilityVSAvoidservice life

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The connection interface is segmented into two distinct functional zones: castellated portions for rotational positioning and shoulders for axial load bearing. This segmentation separates the functions of rotational constraint and axial load transmission, preventing the interlocking features from experiencing harmful cyclic bending loads while maintaining positional stability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Shoulders act as intermediary elements that mediate the axial load transfer between the sleeve and collar. By introducing these intermediate load-bearing surfaces, the design redirects axial forces away from the castellated portions, protecting them from mechanical compromise while maintaining the interlocking connection.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Strength

If castellated portions bear axial loads, then connection strength is improved, but wear and damage accelerate leading to catastrophic failure

Engineering Contradiction:

Improveconnection strengthVSAvoidresistance to wear and damage

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The connection interface is segmented into two distinct functional zones: castellated portions for rotational positioning and shoulders for axial load bearing. This segmentation separates the functions of rotational constraint and axial load transmission, preventing the interlocking features from experiencing harmful cyclic bending loads while maintaining positional stability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Shoulders act as intermediary elements that mediate the axial load transfer between the sleeve and collar. By introducing these intermediate load-bearing surfaces, the design redirects axial forces away from the castellated portions, protecting them from mechanical compromise while maintaining the interlocking connection.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Force

If axial loads are transferred through interlocking features, then load bearing capacity is improved, but cyclic loading accelerates wear and induces early failure

Engineering Contradiction:

Improveaxial load bearing capacityVSAvoidservice duration

Core Design Contradiction:

ForceVSDuration of action of moving object

Solution Approach 1:

The connection interface is segmented into two distinct functional zones: castellated portions for rotational positioning and shoulders for axial load bearing. This segmentation separates the functions of rotational constraint and axial load transmission, preventing the interlocking features from experiencing harmful cyclic bending loads while maintaining positional stability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Shoulders act as intermediary elements that mediate the axial load transfer between the sleeve and collar. By introducing these intermediate load-bearing surfaces, the design redirects axial forces away from the castellated portions, protecting them from mechanical compromise while maintaining the interlocking connection.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS10208546B2Stabilizer assembly

Publication Date: 2019.02.19 SCHLUMBERGER TECH CORP

AI summary

A stabilizer assembly for incorporation in a drill string. The stabilizer assembly includes a tubular member and a stabilizer sleeve slidably disposed about the tubular member. The tubular member has a first castellated portion extending externally around the tubular member, and the stabilizer sleeve has a second castellated portion engaging the first castellated portion. The tubular member includes a first shoulder extending externally around the tubular member, and the stabilizer sleeve further includes a second shoulder extending internally around the stabilizer sleeve. The first and second shoulders at least partially define an annular space between the tubular member and the stabilizer sleeve. A key is disposed within the annular space such that an axial load path between the tubular member and the stabilizer sleeve is substantially through the first and second shoulders and the key and substantially not through the first and second castellated portions.