What Calsep does

Calsep is a privately held Danish software and consulting company headquartered in Kongens Lyngby (Copenhagen), Denmark, founded circa 1982-1989. The company specializes in PVT (Pressure-Volume-Temperature) simulation, equation-of-state (EoS) modeling, and flow assurance software for the oil and gas industry, with growing extension into Carbon Capture and Storage (CCS). Its flagship product, PVTsim Nova, is a modular PVT simulation platform supporting multiple thermodynamic models (SRK, Peng-Robinson, CPA, PC-SAFT, GERG-2008) and interfacing with more than 30 reservoir, flow, and process simulators including OLGA, LedaFlow, Eclipse, tNavigator, Hysys, Prosper, and INTERSECT. PVTsim Nova is sold in modular packages (Basic PVT, PVT Lab, Reservoir, Flow Assurance, OLGA/LedaFlow, Premium, Full Package) plus an optional CCS Module, with expert-assisted Nova Apps such as Auto EoS and Separation App embedding the firm's consulting experience into automated workflows. A Calsep Cloud platform with a Python-based Flash API and private cloud deployment extends the offering into real-time and embedded use cases.

The company's revenue model combines modular software licenses with annual maintenance, professional consulting services for field-wide EoS modeling, asphaltene/wax analysis, and multiphase metering, structured training courses, and the emerging Calsep Cloud / Flash API subscription line. Go-to-market is direct enterprise sales through four wholly-owned regional offices in Copenhagen (HQ and R&D), Houston (Americas), Dubai (Middle East), and Kuala Lumpur (Asia Pacific), supplemented by an active event presence (ADIPEC, User Group Meetings across Houston, Stavanger, Kuala Lumpur, Tokyo, Perth, Abu Dhabi) and technical content via Tech Talks and webinars. Calsep serves reservoir engineers, flow assurance engineers, PVT lab engineers, process engineers, and CCS engineers across more than 300 companies worldwide. The company is founder-managed, has no disclosed external institutional ownership or funding rounds, and notably won a 2022 federal court judgment against former employees for source-code theft.

Name

Calsep

Legal name

Calsep A/S

Website

https://calsep.com

Company type

Private

Founded year

1982

Operating status

Operating

Headcount range

11–50 employees

Short description

Calsep is a privately held Danish software and consulting firm that provides PVT simulation software (PVTsim Nova), equation-of-state modeling, and flow assurance services for reservoir engineers, flow assurance specialists, and CCS engineers across 300+ oil and gas companies worldwide.

Ownership category

akta.pro rank

Headquarters

HQ city

Kongens Lyngby

HQ country

Denmark

HQ region

Europe

Offices4 records

Markets served

GTM type

B2B

Offering type

Software

Cost components

Personnel, Technology or R&D, Operations, Marketing or Sales, Infrastructure

Revenue model

1. Software Licenses (PVTsim Nova): PVTsim Nova is sold as modular packages (Basic PVT, PVT Lab, Reservoir, Flow Assurance, Premium, Full Package) with annual maintenance providing access to latest versions and technical support.
2. Consulting Services: PVT consulting services for Equation of State simulation of reservoir fluid phase behavior, including field-wide EoS modeling, asphaltenes and wax analysis, multiphase meter support, and customized PVT software development.
3. Training and Courses: Open and in-house training courses for reservoir engineers, process engineers, and flow assurance specialists on PVT and phase behavior of reservoir fluids. Courses are held at Calsep offices globally.
4. Calsep Cloud Services: Flash API for performing fast flash calculations via cloud (public or private cloud deployment), Predict Liquid Production service, and Calsep SDKs.

Go-to-market motion2 records

Distribution channels1 record

Marketing channels6 records

Core offering

Calsep develops and sells PVTsim Nova, a proprietary PVT (Pressure-Volume-Temperature) simulation program based on Equation of State (EoS) modeling that is used by reservoir engineers, flow assurance specialists, PVT lab engineers, process engineers, and CCS engineers in the oil and gas industry. The company also delivers PVT consulting services (field-wide EoS modeling, asphaltenes and wax analysis, multiphase meter support, customized PVT software), training courses on reservoir fluid phase behavior, and cloud-based solutions (Flash API, Private Cloud, Predict Liquid Production) through Calsep Cloud.

Product overview

Calsep offers PVTsim Nova as a unified PVT simulation platform with modular architecture. The core product PVTsim Nova is available in multiple package tiers: Basic PVT (entry-level lab data handling), PVT Lab (comprehensive PVT reporting), Reservoir (black oil and compositional reservoir simulation), Flow Assurance (hydrates, wax, asphaltenes management), PVTsim for OLGA/LedaFlow (transient flow simulation), Premium (combined laboratory/reservoir/flow assurance), and Full Package (complete access to all capabilities). An optional CCS Module provides dedicated carbon capture and storage simulation. The product portfolio also includes Calsep Cloud platform with Flash API for real-time cloud-based calculations, Nova Apps for expert-assisted modeling (Auto EoS, Separation App), and professional consulting and training services.

Differentiator

Problem solved

Functional benefit

Brands

• PVTsim Nova: The company's flagship PVT (Pressure-Volume-Temperature) simulation software for reservoir engineers, flow assurance specialists, PVT lab engineers, process engineers, and CCS engineers.
• PVTsim Nova CCS Module
• Nova Apps
• Calsep Cloud

Products and services

• PVTsim Nova Versatile PVT (Pressure-Volume-Temperature) simulation program designed for reservoir engineers, flow assurance specialists, PVT lab engineers, process engineers, and CCS engineers in the energy industry. Supports multiple thermodynamic models (SRK, Peng-Robinson, CPA, PC-SAFT, GERG-2008, Huron-Vidal) and integrates with 30+ reservoir, flow, and process simulators. Trusted by over 300 companies worldwide.
• PVTsim Nova CCS Module Dedicated Carbon Capture and Storage (CCS) simulation module integrated with PVTsim Nova, providing CO2 and H2 specific EoS models, brine solubility simulations, accurate CO2 hydrate predictions, hydrate PT and PH phase mapping, impurity impact investigation, and PH/PT phase envelopes for CCS engineers and researchers.
• Nova Apps

Quantifiable outcome

• Develop EoS model within minutes using automated Auto EoS feature
• +2 more outcomes

Segments5 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

Yes

API docs

API detail

Core technology

AI maturity

App detail

Integration19 records

AI capability3 records

Feature6 records

Scale indicators3 records

Recent moves6 records

Expansion highlights6 records

Broad incumbents

• SLB (Schlumberger): SLB offers the ECLIPSE compositional reservoir simulator and the INTERSECT platform — broad oilfield-services incumbents with embedded PVT and EoS capabilities that compete for the same customer wallet.
• KBC (Yokogawa): KBC (a Yokogawa company) delivers process simulation, digital twin, and consulting services to the energy and chemicals sectors, overlapping with Calsep's process-engineering and consulting offerings.
• Halliburton Landmark: Halliburton's Landmark business (DecisionSpace, INTERSECT) competes with Calsep by bundling PVT and fluid-property features inside its integrated reservoir and drilling software suites.
• Aspen Technology (Emerson): AspenTech (now part of Emerson) provides process-simulation software (HYSYS, Aspen Plus) used by Calsep's process-engineering customers; an overlapping but broader incumbent in hydrocarbon process modeling.

Emerging players

• Roxar (Emerson): Roxar (Emerson) offers reservoir management and flow-assurance software (Tempest, RMS) targeting similar reservoir-engineering and pipeline operators as Calsep.
• OLI Systems: OLI provides electrolyte and rigorous thermodynamic simulation used in upstream water chemistry, sour-service, and CCS-related applications — an adjacent specialist that overlaps with parts of Calsep's polar-component and CCS modeling.

Direct peers

• Computer Modelling Group (CMG): CMG builds reservoir simulation suites (GEM, IMEX, STARS) widely used by Calsep's reservoir-engineering customers, making it the closest competitor for fluid-modeling and EoS-dependent reservoir workflows.
• Infochem (S&P Global Commodity Insights): Infochem provides PVT, multiphase flow, and wax/asphaltene software for the oil & gas industry — historically Calsep's closest direct competitor in standalone PVT simulation, now part of S&P Global Commodity Insights.
• Petroleum Experts (Petex): Petex provides integrated production modeling tools (Prosper, MBAL, GAP) that Calsep's PVTsim interfaces with directly, serving the same reservoir and production-engineering personas.

Others

• Beicip-Franlab: Beicip-Franlab provides reservoir consulting and PVT/EoS studies to IOCs and NOCs — adjacent rather than directly competitive, but drawing on the same domain expertise and often paired with Calsep-style tools.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat6 records

Key risks7 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/calsep-a-s

Revenue estimate

Valuation estimate

Number of profiles

Profiles11 records

Subsidiaries3 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Calsep