OLGA-S is the steady-state prediction routine, or point model, from the OLGA* dynamic multiphase flow simulator. It is a mechanistic model that simulates each of the flow regimes in multiphase flow and determines the main flow properties, such as pressure drop, hold-up and flow regime. OLGA-S is developed by Schlumberger in cooperation with the Institute for Energy Technology. OLGA-S is delivered in binary form as a library that can be dynamically linked to a driver program. Most steady-state pipeline simulators have OLGA-S incorporated as a possible flow correlation, in addition to the standard correlations.