The OLGA dynamic multiphase flow simulator models transient flow (time-dependent behaviors) to maximize production potential. Transient modeling is an essential component for feasibility studies and field development design. Dynamic simulation is essential in deep water and is used extensively in both off- and onshore developments to investigate transient behavior in pipelines and wellbores.
Transient simulation with the OLGA simulator provides an added dimension to steady-state analysis by predicting system dynamics, such as time-varying changes in flow rates, fluid compositions, temperature, solids deposition, and operational changes.
From wellbore dynamics for any well completion to pipeline systems with various types of process equipment, the OLGA simulator provides an accurate prediction of key operational conditions involving transient flow.
Improved survey data smoothing and simplification
OLGA 2018.1 provides improved means to create pipeline geometries from survey data in the Profile generator. A new filtering method is introduced to remove noise and smoothen the survey data. Furthermore, a new simplification method is introduced that can automatically optimize the simplification while avoiding the dependency on carefully selected angle groups. Both methods increase automation and reduce the need for user input.
More flexible simulation initialization
OLGA 2018.1 extends the simulation initialization capabilities with the ability to combine the three existing methods: initial conditions, steady state preprocessor, and restart. This flexibility enables adding a new well or tie-in to the simulation model of an existing field and using a restart file to initialize the existing parts of the model while using the steady-state preprocessor or initial conditions to initialize new parts.
Hydrate Kinetics models in Engine Extensibility framework
OLGA 2018.1 makes the Engine Extensibility interface available for Hydrate Kinetics functionality. This enables the utilization of new and updated third-party functionality for oil and water dominant systems from Colorado School of Mines, as well as new functionality for gas dominant systems provided by University of Western Australia. The functionality is delivered as extensions to OLGA, not as integrated functionality.
Improved stability-based time step control
OLGA 2018.1 incorporates a revised Courant-Friedrichs-Lewy (CFL) criterion for optional use. While the original CFL criterion in OLGA is based on the mass transport velocities, the revised criterion is an approximation of the numerical stability criterion for OLGA based on the maximum interfacial wave speed of the moving fluids. This criterion enables quickly bringing a simulation to dynamic steady state but should be applied with care when resolving detailed transient phenomena.
New simulation output for calculation of momentum forces
OLGA 2018.1 provides momentum flux as a simulation output to support the calculation of momentum forces acting on pipes. This is particularly of interest in slug flow where the alternating slugs and slug bubbles cause large variations in the forces, which can lead to vibrations in pipelines. Furthermore, OLGA 2018.1 can report the maximum momentum flux that may occur in the short mixing zone behind a slug front to aid in addressing the forces exerted on pipe bends and in stress analysis.
New slug flow output variables
OLGA 2018.1 broadens the information derived from the slug unit cell model. Previously, only average values were reported (e.g., for volume fractions). Now, additional output, as volume fractions in the associated slug body and slug bubble zones, is available. The new output provides useful information, but it cannot replace the detailed output obtainable from slug tracking simulations.
OLGA delivered as 64-bit application
OLGA 2018.1 is delivered as a 64-bit application only and is not offered as a 32-bit application. This transition facilitates the use of modern hardware and instruction sets offered only within 64-bit operating systems.