MULTICORP V4.2 Software

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The ICMT's latest release, the transient mechanistic CO₂ corrosion prediction software package MULTICORP V4.2, provides many new capabilities and enhancements that allow the user to significantly expand the scope of internal pipeline corrosion analyses:

• Mechanistic model of CO₂ and H2S corrosion mechanism,
• Capability to perform batch run for a set of experimental data,
• Capability to perform Monte Carlo simulation of the corrosion process for uncertain data,
• Corrosion prediction correction based on the field data using case-based reasoning,
• Oil pipeline corrosion prediction with transition along the line

MULTICORP 4.2 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.

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MULTICORP V4.2 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 V4.2 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 V4.2 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 V4.2 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 V4.2 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 V4.2 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 V4.2 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.

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MULTICORP4.2 enables users to define a series of corrosion parameters (point), execute all of them in batch mode and provide graphical results of corrosion trends.

Batch run results.

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MULTICORP 4.2 allows corrosion engineers to define their pipeline configuration (dimensions, length, inclination, insulation) and run corrosion prediction along the pipeline with pressure, temperature and environment changes and variations along the line.

Line run results.

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MULTICORP V4.2 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 V4.2 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 V3 for top-of-the-line corrosion, WWCORP V1 for accurate prediction of water wetting, are also available.

In summary MULTICORP V4.2 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 V4.2 can be obtained by joining the CC JIP.

MULTICORP V5 is expected to debut in late 2011 with a full mechanistic model of localized corrosion, new platform (VBasic 2008), new corrosion simulator, and functionality to interact with other flow modeling/corrosion software products.