Cementing Products

CentraPro Plus®

Centralizer Placement SystemCareful planning and engineering are critical for the success of the cementing job with propercentralization necessary for good mud removal. The optimum placement of centralizers establishes theachievable standoff.

Additionally, in highly inclined and horizontal well situations, optimum placement minimizes frictionforces and thereby ensures a casing can be run safely to bottom.

The all new centralizer placement software of Weatherford contains a completelyrevised mathematical simulation model. software calculates the optimum standoff, aswell as precise torque and drag simulation.

CentraPro PlusCentraPro Plus

A new mathematical simulation model based onrevised API-10D formulas is used to calculatethe optimum spacing of centralizers to obtainthe best standoff at a given borehole depth.

The latest model takes into account relevantfactors such as:

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The lateral force at any given location basedon borehole geometry, buoyed string weightsand tension forces

The reaction of the centralizer exposed tothese forces, based on actual test data foreach pipe size/hole size combination

The sag between centralizers based on theelasticity of the pipe and a three-dimensionalvector analysis of the weight and tensioncomponentsThe revised mathematical model incorporates a

torque and drag analysis that accounts for theknown running forces of the centralizers, as wellas the friction factors which depend on the mudtype. This analysis is imperative to evaluatewhether the desired centralizer spacing can berun or rotated without delays, problems due tohigh drag forces or damaging the pipeconnections. The equations on which thesemodels are based were completely developed byWeatherford.

Torque and Drag

Mathematical Model

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Model Variations Databases

Presentation of Data

Technical Support

The new software allows several variations to simulatedifferent borehole situations. The buyoed weight of thestring, for example, can be based on the cement slurryweight, the mud weight or a combination of both.

The model can be run either in the “fixed standoff”mode, which results in a spacing required to obtain aparticular standoff, or in the “fixed spacing” mode,which results in a standoff at each centralizer location.

All relevant centralizer data and pipeinformation are stored in databases. Thisminimizes the possibility of human inputerrors. Each wellfile contains relevant dataon each casing or liner string (called ‘jobs’).

Each job may be divided into sections thatallow the variation of parameters such as holesize, centralizer type and spacing, frictionfactors and pipe data.

Results of the simulation are presented in a way whichcan easily be read and interpreted. A completeoverview of the standoff, required number ofcentralizers and stop collars, as well as the torque anddrag figures are printed in tabular as well as graphicalform.

CentraPro Plus software installations arebased strategically in technical supportcenters around the globe. Experiencedpersonnel are ready to assist you in theoptimum placement of centralizers for allkinds of situations. For more information,please contact your nearest Weatherfordrepresentative.

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