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    Reservoir Fluid Modeling

Modeling of reservoir fluid properties is Calsep’s core expertise. Calsep undertakes equation of state (EoS) modeling projects for

  • Acid gases
  • Gas condensates
  • Near critical fluids
  • Volatile oils
  • Black oils
  • Heavy oils

Calsep may assist in all phases of an EoS modeling project:

  • QC of the sampled compositions
  • Planning of PVT experiments
  • Component lumping
  • Regression to experimental PVT data
  • Export of developed EoS model to reservoir simulators
  • Evaluation of existing EoS models
  • Cleaning for Oil-Based Mud (OBM) Contamination

QC of the Sampled Compositions

PVT experiments performed on reservoir fluids are costly and often used to make decisions about production strategy as well as in reserve estimations. For these reasons it is important that the fluid sample is representative of the reservoir fluid. Calsep can carry out a series of Quality Check tests on the sampled fluid compositions (bottom-hole or separator sampled). If certain tests fail, Calsep would also be able to recommend whether the sample can be used for EoS modeling purposes or must be discarded.

Contact Calsep for more information

Planning of PVT Measurements

Calsep can offer support designing a fluid sampling and a PVT laboratory program. Factors influencing the design are

  • Fluid type
  • Reservoir pressure and temperature
  • Production strategy to be applied
  • Likely presence of asphaltenes
  • Risk of wax precipitation in the production well

Contact Calsep for more information

Regression to Experimental PVT Data

It is common practice in the oil industry to have the following routine PVT experiments carried out: 

  • Constant Mass Expansion
  • Differential Liberation (only oils)
  • Constant Volume Depletion (gas condensate and volatile oils)
  • Separator Tests

An EoS model must provide a good match of the experimental data. In compositional simulations heavy lumping is needed and regression to PVT data is generally required to match the data.

Calsep can carry out regression to PVT data for the above mentioned experiments and provide a component lumping scheme that fits the actual application.

Contact Calsep for more information

Export of developed EOS model to reservoir simulators

Calsep can export to the following reservoir simulators 

  • Eclipse (100, 200 and 300)
  • VIP (Comp and Black Oil)
  • More (EoS and Black oil)
  • CMG simulators (IMEX, GEM and STARS)

Contact Calsep for more information

EOS Model Evaluation

An existing EoS model may have to be revisited, either because new experimental information has become available or the production strategy is going to be changed. Calsep has developed procedures, which can accurately determine whether an existing EoS model is applicable not only for the purpose it was developed for, but can also be used in for example flow studies or if the production strategy is to be changed from natural depletion to gas injection EOR.

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Cleaning for Oil-Based Mud Contamination

Reservoir samples are often contaminated by base oil from drilling mud. Calsep provides consulting in order to estimate the composition of a reservoir fluid from a sample with a certain content of base oil contaminate. Calsep can also carry out regression to experimental PVT data for a contaminated fluid and provide a regressed non-contaminated fluid composition.

Contact Calsep for more information