PVT Consulting and Simulation Software

Calsep is a leading provider of PVT simulation services to the oil and gas industry

Calsep has more than 30 years of experience working with the oil industry on projects related to reservoir fluid phase behavior. That allows us to offer knowledge-based PVT simulation software and studies within EoS modeling of all kinds of fluids including natural gases, gas condensates, near critical fluids, black oils, and heavy oils. Calsep undertakes projects with application for reservoir simulation, flow assurance, and process simulation.

Read more about Calsep


International experts in EOS modeling

Calsep undertakes fluid modeling studies assessing all stages of production. The studies may cover the effect of injection gas in the reservoir for EOR purposes as well as the risk and mitigation of solid precipitation in wells and pipelines. Calsep can deliver fluid property or composition input files for more than 20 different reservoir, flow and process simulators.

Read all about our services


Develop your own PVT modeling skills

Calsep offers open courses as well as in-house courses to reservoir engineers, process engineers, engineers dealing with flow assurance or multi-phase flow metering, laboratory staff and others needing to apply PVT simulation software in their work.

Read more about Courses

PVTsim Nova

A leading PVT simulation software

PVTsim Nova was launched May 2014 as a new generation of the PVTsim software package that has been continuously developed since the first version was released in 1988. Powerful and reliable simulation options wrapped in a user-friendly graphical user interface has made PVTsim the preferred PVT simulation tool of more than 200 companies in oil and gas industry.

Read more about PVTsim Nova

Monthly Tech talk
Monthly Tech talk

Huron-Vidal Mixing Rule. A Unique Combination of a Cubic Equation and a GE model.

Cubic equations have been an industrial standard in oil industry since the nineteen eighties, but in the original form those equations are unable to handle the mutual solubility between hydrocarbons and aqueous components. Formation water is often produced together with petroleum reservoir fluids and hydrate inhibitors may have to be added to prevent hydrate formation when unprocessed well streams are transported in subsea pipelines.

The chemical industry has long used the so-called GE (or Excess Gibbs Energy) models to handle mixtures of water, alcohols and glycols. Examples are UNIFAC, UNIQUAC, and NRTL. Water and hydrate inhibitors are polar compounds. At a molecular level these components form clusters when dissolved into a hydrocarbon phase. This is inconsistent with the classical mixing rules, which assumes a random distribution of molecules. The GE models have never obtained widespread use in the oil industry because the models are inapplicable at pressure higher than around 10 bar/1470 psi.

Read previous tech talks