Peter Jørgensen Herslund

Senior Consultant

Calsep Copenhagen

Consulting Services, examples

Common EoS modelling for 6 OBM contaminated CO2 rich reservoir fluids (2015)
An SRK-Peneloux common EoS model was developed for six reservoir fluids, all with very high CO2 contents. An excellent match of all routine PVT data was obtained through parameter regression and simultaneous adjustment of binary interaction coefficients between CO2 and the C7+ hydrocarbon fractions. The Corresponding-States-Principle (CSP) viscosity model was applied successfully to simulate oil and gas viscosities in this system. The project also included a communication study by depth gradient simulation to investigate possible communication between sampling locations in the reservoir.

Extensive QC and common EoS modelling of 17 reservoir fluid samples from the North Sea (2018).
An extensive quality check was conducted for 17 reservoir fluid samples originating from the same reservoir in the North Sea. The QC involved compositional fluid QC, analyses of depth gradient trends, communication studies and consistency checks with historical production data. Two new common EoS models were developed based on 11 fluid samples that passed the extensive QC. The two models were developed with special focus on gas injection EOR data, as they would be applied for both history matching and simulation of future production scenarios involving WAG.

Wax deposition simulations for a 20 km, 8” subsea pipeline (2017).
A common EoS model was developed for 13 well stream compositions. The model was tuned to match recent well test data and wax onset measurements. A DepoWax case for the pipeline, including two vertical risers, was set up in PVTsim Nova. Steady state flow simulations were conducted for 12 production scenarios covering both summer and winter conditions. No wax deposits were found, when all 13 wells produced into the pipeline. If one or more wells were taken off-line, wax deposition and buildup was found in short distance from the pipeline inlet.

General flow assurance study (2013).
A flow assurance study was performed for two reservoir fluid samples. The study involved simulation of asphaltene onset at reservoir conditions with and without gas injection. An evaluation of wax precipitation risk was performed. Gas hydrate curves were simulated at various production scenarios (various water cuts) and with both methanol and mono-ethylene-glycol as inhibitors. A scale precipitation study was performed for a supplied formation water analysis. Scenarios both with and without sea water injection was considered.

Research Calsep Project, examples

Verification reports (2014 – 2019)
Collection and sorting of relevant experimental data. Automated calculations using PVTsim Open Structure to generate verification reports for; Mutual solubilities in water and gas systems (special attention to CO2 and H2S), Scale (special attention to acid gas sensitive scaling systems).

Parameterization of EoS models in PVTsim Nova (2014 – 2017).
More than 15,000 experimental phase equilibrium data points for pure components, binary and multi-component systems were checked for consistency. Approximately 11,000 data points were selected and new parameters regressed for various components and models in PVTsim Nova (SRK-CPA, PR-CPA, PR-HV, Gas Hydrates).


Sørensen, H., Boesen, R.R., Leekumjorn S. and Herslund, P.J.
Peng-Robinson Equation of State Extended to Handle Aqueous Components Using CPA Concept.
Journal of Natural Gas Engineering, 3 (1), 2018, pp. 1-38.

Boesen, R. R., Herslund, P. J., and Sørensen, H.
Loss of Monoethylene Glycol to CO2-and H2S-Rich Fluids:
Modeled Using Soave–Redlich–Kwong with the Huron and Vidal Mixing Rule and Cubic-Plus-Association Equations of State.

Energy & Fuels 31, 2017, pp. 3417–3426.

Herslund, P.J., Daraboina, N., Thomsen, K., Abildskov, J. and von Solms, N.
Measuring and modelling of the combined thermodynamic promoting effect of tetrahydrofuran and cyclopentane on carbon dioxide hydrates.
Fluid Phase Equilibria Volume 381, 15 November 2014, Pages 20–27.

Herslund, P.J., Thomsen, K., Abildskov, J. and von Solms, N
Modelling of cyclopentane promoted gas hydrate systems for carbon dioxide capture processes.
Fluid Phase Equilibria Volume 375, 15 August 2014, Pages 89–103.

Herslund, P.J., Thomsen,K., Abildskov,J. and von Solms, N.
Modelling of tetrahydrofuran promoted gas hydrate systems for carbon dioxide capture processes.
Fluid Phase Equilibria Volume 375, 15 August 2014, Pages 45–65.

Herslund, P.J., Thomsen, K., Abildskov, J., von Solms, N., Galfré, A., Brântuas, P., Kwaterski, M., Herri, J.-M.
Thermodynamic promotion of carbon dioxide–clathrate hydrate formation by tetrahydrofuran, cyclopentane and their mixtures.
International Journal of Greenhouse Gas Control 17 (2013) 397-410.

Herslund, P.J., Thomsen, K., Abildskov, J., von Solms, N.
Application of the Cubic-Plus-Association (CPA) Equation of State to Model the Fluid Phase Behaviour of Binary Mixtures of Water and Tetrahydrofuran.
Fluid Phase Equilibria 356 (2013) 209-222.

Herslund, P.J., Thomsen, K., Abildskov, J., von Solms, N.
Phase equilibrium modeling of gas hydrate systems for CO2 capture.
Journal of Chemical Thermodynamics 48 (2012) 13-27.


2017 – 2021


Graduate Diploma in Business Administration (International Business), Copenhagen Business School, Denmark
2010 – 2013   Ph.d. in Chemical Engineering, Technical University of Denmark, Denmark.
2003 – 2009 M.Sc. in Chemical Engineering, Technical University of Denmark, Denmark.



2013 – Senior Consultant, Calsep A/S, Denmark.
2010 – 2013 Ph.d. Student, Technical University of Denmark, Denmark.
2009 – 2010 Research Assistant, Technical University of Denmark, Denmark.


For more information about Calsep office locations, phone and fax numbers, please go to Calsep locations.


Calsep A/S
Headquarter & Europe


Calsep FZ LLC
Middle East


Calsep, Inc.

Kuala Lumpur

Calsep Asia Pacific Sdn Bhd
Asia and Pacific