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The ICMT's latest release, the transient mechanistic CO2 corrosion prediction
software package MULTICORP V4, provides many new capabilities and enhancements that allow the user to
significantly expand the scope of internal pipeline corrosion analyses. It covers almost all key aspects
of internal corrosion of mild steel oil and gas pipelines and is based on solid theoretical foundations,
which include the models of:
- Kinetics of electrochemical reactions at the steel surface, such as iron dissolution, hydrogen evolution, etc.
- Kinetics of solid state reactions at the steel surface, such as mackinawite scale buildup.
- Dynamics of coupled transient transport of multiple species between the bulk solution and the steel surface, through the turbulent boundary layer and through a porous surface film.
- Kinetics of chemical reactions including precipitation of solids such as iron sulfide, iron carbonate, etc.
- Growth of iron carbonate and iron sulfide scales
Therefore it is possible to reliably predict the effects of key variables that affect
internal pipeline corrosion such as:
- Effect of multiphase flow (two- and three-phase flow)
- Effect of temperature (1-100 °C)
- Effect of CO2 partial pressure (0 – 2 MPa)
- Effect of H2S content (0 – 1 MPa)
- Effect of organic acids (0 – 10,000 ppm)
- Effect of pH and brine chemistry (pH3 – pH7)
- Effect of steel type
- Effect of inhibition by crude oil and/or corrosion inhibitors
- Magnitude and morphology of localized attack

Main input screen where the key parameters are specified.
MULTICORP V4 has many advantages when compared to other related software packages available to users.
As the package is based on a mechanistic (theoretical) model, the equations behind MULTICORP V4 are faithful
descriptors of the important physico-chemical processes underlying corrosion. This is in contrast with the
other models, all of which are empirical or semi-empirical. This mechanistic approach offers many advantages
some of which are listed below.
Besides providing immediate answers - e.g. the corrosion rate, the package allows the
users to get a deeper insight into the root causes behind the problem, thereby raising the user's confidence
in the provided answer. The other empirical models based on arbitrary mathematical equations lack this
capability, completely or in part. Due to the strong theoretical background, the user can extrapolate
the predictions outside the calibration domain with much more confidence then can ever be achieved with
the (semi) empirical models whose extrapolation capabilities are questionable. Any extensions of the
model to include new phenomena (for example: sand, elemental sulfur, microbial corrosion, etc.) can be
done relatively easily, in a logical fashion, and without changing most of the existing coding. This
is in contrast with the extensions of (semi) empirical models which are cumbersome and often
prohibitively difficult.
MULTICORP V4 is the one of the few packages that seamlessly integrates a corrosion model
with a multiphase flow model a feature much needed by the corrosion engineers. It is the only package that
enables successful prediction of one of the most important multiphase flow effects on corrosion which is
related to water wetting and entrainment of water by the oil phase. It can be easily coupled with other
multiphase flow simulators.
MULTICORP V4 includes the brand new mechanistic
model of sour corrosion (H2S effect) which is fully integrated
with the CO2 corrosion model and is calibrated with both
short and long term corrosion data.
MULTICORP V4 has a simple yet powerful water chemistry model which can predict speciation and
pH of brine and the effect that these have on the corrosion rate.
MULTICORP V4 is the only package that has a full blown model of the effect of organic acids built in.
The same is true for a unique model of corrosion inhibition by crude oils. It is the only model that can accurately
predict corrosion at very low temperatures (1°C) as well as high salinity brines (25% NaCl).
MULTICORP V4 is the only package that enables fundamentally correct and reliable prediction of
conditions where protective iron carbonate and iron sulfide scales form which can help mild steel survive the corrosive
conditions found in pipelines. Other models are either incapable of predicting protective scale formation or have
arbitrary and dubious factors to account for this phenomena.

Processing window where the development of the corrosion rate and surface scales can be tracked as a function of time.
MULTICORP V4 package has been extensively calibrated and verified with a reliable experimental database.
Most of the data came from large-scale corrosion and multiphase flow laboratory experiments. In addition, a reliable
field corrosion database, provided by the major oil and gas companies, has been used to verify the performance of the model.
MULTICORP V4 package has a huge growth potential not least because it is the only software of its kind
which is produced by a leading research institution (ICMT). Therefore, MULTICORP developers have exclusive and continuous
access to the latest research results generated at ICMT and interact closely and frequently with the experts from the
leading oil and gas companies which sponsor ICMT.
MULTICORP plugin modules such the TOPCORP V2 for top-of-the-line corrosion, WWCORP V1 for
accurate prediction of water wetting, are also available.
In summary MULTICORP V4 is a unique software package both in scope and approach. With its current and
future development which is backed up by ICMT sponsors and ICMT ongoing experimental programs it is rapidly becoming
and industrial leader for prediction of internal corrosion of oil and gas pipelines.
MULTICORP V4 can be obtained by joining the CC JIP.
MULTICORP V5 is expected to debut in 2009 with a full blow mechanistic model of localized corrosion.
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