Hydroformed Pipe Centralizer Ribs Eccentricity Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing centralizers for tubular strings in well bores often fail to adequately prevent eccentricity and contact with the borehole wall, requiring more robust and easily attachable solutions that can withstand drilling rotation and varying drilling conditions.

Innovation Solution

A hydroformed centralizer with outwardly projecting ribs is developed, which can be attached to pipes using crimping or stop rings, allowing for secure positioning and rotation, and is manufactured through a process involving a mold with cavities that shape the ribs by applying fluid pressure to the tubular work piece.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional centralizers are used, then they can be attached to pipe, but they fail to adequately prevent eccentricity and contact with the borehole wall

Engineering Contradiction:

Improveability to prevent eccentricityVSAvoidstructural capacity

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The centralizer body is segmented into multiple outwardly projecting ribs that contact the borehole wall. These ribs divide the centralizing function into multiple contact points around the circumference, providing distributed support and preventing eccentricity more effectively than a smooth centralizer body.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention transitions from a two-dimensional smooth centralizer surface to a three-dimensional structure with outwardly projecting ribs. This adds radial dimensionality to the contact surfaces, creating multiple levels of contact points that enhance the centralizer's ability to prevent eccentricity and withstand drilling forces.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Strength

If robust centralizers are designed to withstand drilling forces, then structural integrity is improved, but attachment complexity increases

Engineering Contradiction:

Improveresistance to drilling forcesVSAvoidattachment method complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The attachment means are merged with the centralizer body itself, forming an integrated structure. The attachment means include features such as external threads, lugs, or other attachment elements that are part of the centralizer body, eliminating the need for separate attachment components and simplifying the overall attachment process.

Inventive Principle:

Principle #5Merging (Combining)

3Duration of action of stationary object

If centralizers are designed for drilling with casing applications, then rotational durability is improved, but manufacturing complexity increases

Engineering Contradiction:

Improverotational durabilityVSAvoidmanufacturing simplicity

Core Design Contradiction:

Duration of action of stationary objectVSEase of manufacture

Solution Approach 1:

The hydroforming process uses hydraulic pressure to form the ribs and shape the centralizer body. Fluid pressure is applied to a hollow centralizer blank to plastically deform the metal into the desired ribbed configuration, providing a efficient manufacturing method for complex geometries.

Inventive Principle:

Principle #29Pneumatics and hydraulics

Solution Approach 2:

The hydroforming process changes the physical parameters of the centralizer blank through controlled plastic deformation. By applying hydraulic pressure and controlling the forming parameters, the metal is transformed from a simple cylindrical blank into a complex ribbed structure with enhanced mechanical properties.

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

The hydroformed centralizer effectively reduces eccentricity and withstands drilling forces, providing structural integrity and flexibility in attachment methods to suit various drilling applications, including those requiring rotation and axial positioning control.

Implementation Method 1

applying sufficient pressure to the side wall through the inner bore to force the tubular sidewall radially outward against the confining surface

Methodology Applied

Scientific EffectHydraulic pressure: Pressure Increase

Implementation Method 2

plastically deform the side wall to form centralizer ribs on the side wall

Methodology Applied

Scientific EffectPlastic deformation: Plasticity

Data Source

PatentUS7814633B2Pipe centralizer and method of forming

Publication Date: 2010.10.19 NABORS DRILLING TECHNOLOGIES USA INC

AI summary

A centralizer for installing on a metal pipe. The centralizer includes a generally tubular body having a central opening sufficiently large to allow insertion therethrough of a pipe having an external diameter; a sidewall of substantially uniform thickness including an inner-facing surface directed to the central opening and an outer-facing surface onto which are formed a plurality of outwardly protruding ribs by hydroforming the sidewall. A method for hydroforming a centralizer including placing a length of metal tubular work piece, the work piece having a sidewall and an central opening, inside a confining surface comprised of mold elements, the mold elements including cavities spaced and shaped in the configuration of desired side wall centralizer ribs, the mold elements being supported substantially against expansion radially outward from their position about the tubular work piece; applying sufficient pressure to the side wall through the inner bore to force the tubular sidewall radially outward against the confining surface and into the mold cavities to plastically deform the side wall to form centralizer ribs on the side wall; and removing the tubular work piece from the confining surface.