Production
The temperatures and pressures encountered during most production trains are normally low enough for Equation of State (EOS) predictions to be very reliable. However many contaminants such as CO2, H2S, and mercaptans have a polar nature and complex phase behaviour. The partitioning between phases of these contaminants requires careful modelling using an appropriate EOS.
Flow assurance issues such as wax deposition, hydrate formation, and asphaltene dropout are major concerns when planning production systems. Understanding these complex phase behaviours can only be achieved by devising a careful sampling program, and performing specialist PVT studies. Our in-house software is designed to model such complex phase behaviours and can also model multiphase flow pipeline pressure drops and Joule-Thomson temperature drops.
The flexible nature of spreadsheet modelling enables a continuous sequence of phase behaviour calculations to be performed from reservoir through all stages of production to export conditions. This has proved a valuable tool for modelling the export liquid and gas volumes from the commingled production from condensate reservoirs. As a stand alone tool this provides an accurate method of monitoring liquids allocation, and in conjunction with reservoir simulation data an effective method for predicting liquids production. It also provides a useful benchmark when devising more complex Integrated Asset Models.
Case studies