Bow-Spring Centralizer Heel Support Reduces Friction

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Solution Overview

Problem

Conventional bow-spring centralizers experience high frictional resistance during rotation, leading to torque issues and potential damage to wellheads and downhole equipment, as they compress and contact the outer surface of the central tubular member, especially when passing through restrictions.

Innovation Solution

A bow-spring centralizer assembly with a heel support member that prevents bow spring members from contacting the outer surface of the central tubular member, combined with friction-reducing means such as bearings and non-abrasive materials to minimize torque and wear, and a bolster assembly for protection during handling and storage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional bow-spring centralizers are used to center casing strings, then casing centralization is achieved, but high frictional resistance and torque issues occur during rotation

Engineering Contradiction:
Improvecasing centralizationVSAvoidfrictional resistance and torque
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a heel support member as an intermediary component between the bow spring and the tubular member. This heel support member prevents direct contact between the bow spring and the tubular member surface, thereby reducing frictional resistance and torque during rotation while maintaining the centralization function.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If bow springs are compressed to pass through restrictions, then the centralizer can navigate wellbore restrictions, but the bow springs contact and damage the outer surface of the central tubular member

Engineering Contradiction:
Improveability to pass through restrictionsVSAvoiddamage to tubular member surface
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The heel support member serves as a protective intermediary that prevents the bow spring from directly contacting and damaging the tubular member surface during compression and passage through restrictions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The heel support member is positioned in advance to cushion and protect the tubular member surface before any potential contact with compressed bow springs occurs during restriction passage.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Ease of operation

If friction-reducing means such as bearings are added to reduce torque, then rotation becomes smoother, but device complexity increases

Engineering Contradiction:
Improverotation smoothnessVSAvoidcentralizer structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The heel support member acts as a simple intermediary structure that reduces friction without requiring complex bearing assemblies or additional mechanical components, thereby maintaining operational ease while avoiding increased device complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 reduces frictional resistance and damage to wellheads, allowing for smoother rotation and improved sealing, while protecting the centralizer from damage during transportation and handling.

Implementation Method 1

A plurality of bow spring members extends between said end bands, with said bow spring members biasing said end bands toward each other

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

A bow spring heel support member to prevent such bow spring members from contacting the outer surface of said central tubular member when said bow springs are compressed

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2828467B1Well centralizer
Publication Date: 2018.04.25 BLACKHAWK SPECIALTY TOOLS LLC
  • EP2828467B1 patent drawingFigure 1
  • EP2828467B1 patent drawingFigure 2~3
  • EP2828467B1 patent drawingFigure 4~5

AI summary

A centralizer assembly (1) has a central tubular body member (10) with upper channel (12) and lower channel (15) extending around the external surface of said central tubular body member. A bow spring assembly (100) having bow spring members (110) is installed around the outer surface of the tubular body member (10) and can rotate about the outer surface of the central tubular body member. Bow spring heel supports prevent the bow spring members (110) from contacting the outer surface of the central tubular member (10) when compressed. Non-abrasive materials prevent damage to wellhead or other polished bore receptacles. A robust bolster frame protects the centralizer assembly during shipping, storage or other periods of non-use.