About Calsep
Calsep stands for CALculation of SEParation processes. Calsep is a specialist company within oil and gas properties and phase equilibria. Consulting services, PVT and flow assurance software are the main products.

35 years of PVT services
From the first beta version and client to being a benchmark software and consultancy company.
At Calsep we are continuesly improving our software adapting to new technologies, consumer behaviour and tendencies in the oil and gas industry. From a humble start in Copenhagen in 1982 to offices in 4 continents offering services to the leading companies in the oil, gas and polymer industry.
Offices
For more information about Calsep office locations, phone and fax numbers, please go to Calsep locations.
For more information about Calsep office locations, phone and fax numbers, please go to Calsep locations.
For more information about Calsep office locations, phone and fax numbers, please go to Calsep locations.


Global team
At Calsep we reach all continents, of course via online meetings but also via our staff and representation in United States, Europe, Asia and in the Middle East. For us it is a big value to be present where our clients typically operate.
Get to know us better:
Latest News
PVTsim Nova User Group Meeting, November 24, Tokyo
We would like to invite PVTsim Users in Japan for an in-person PVTsim user group meeting at ANA InterContinental, Tokyo November 24. Come join us and learn about the latest updates and upgrades in PVTsim…
PVTsim Nova User Group Meeting, November 3, Stavanger
We would like to invite you for an in-person PVTsim user group meeting at Clarion Hotel Stavanger November 3. Come join us and learn about the latest updates and upgrades in PVTsim Nova 6.0 and…
PVTsim Nova 6.0 Released
Calsep is happy to announce that PVTsim Nova 6.0 has been released and it can be downloaded from Client Area. For more information about all the updates and bug fixes check out the list of updates…
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Publications
Open book policy
It is Calsep policy to publish our research results on improved techniques for fluid description and modeling of phase equilibria. The research and development work has been documented in more than 60 publications and 2 textbooks, all authored or coauthored by Calsep’s consultants.
The publications cover subjects like:
- EOS modeling
- Solids precipitation and deposition
- Computer algorithms for solving phase equilibria