Atmos Simulation Suite has a range of powerful and user friendly tools to assist operators in monitoring their pipelines.
Using a simulation system can offer the following benefits for both gas and liquid pipelines:
- Pipeline hydraulic information in unmetered areas
- Model-based leak detection
- Forecasting of future pipeline operations
- Revenue increase
- Modelling of different operating scenarios
- Training and pipeline design
Running online simulations and look-ahead modelling on a pipeline can save operating companies millions of dollars a year.
Atmos’ simulation products use a unique state estimator to provide the most robust, reliable, and accurate on-line simulation results in the market. It minimizes the effect of measurement errors by the use of confidence levels in individual meters. This is especially useful for large pipeline networks.
The simulation products can model the hydraulic behaviour of both gas and liquid pipelines accurately. The same configuration applies to both online and offline systems, and the online saved states can be imported to offline systems for realistic scenario analysis and emergency studies.
Simulation systems can have significant financial benefit for operating companies. The world’s largest subsea pipeline operator, Gassco, uses Atmos SIM Online to monitor their pipelines. They transport approximately 100 billion standard cubic meters (3.5 x106 MMSCF) of Norwegian natural gas to the European market through 8000km (5000 miles) of large diameter high-pressure subsea pipelines each year. A cost benefit analysis showed a minimum saving of USD 7.5 Million per annum to Gassco as a result of improved decision making based on running a few operational scenario simulations.
Other benefits of the simulation systems include the ability to simplify and speed up tasks that are essential to the safe running of the pipelines. Atmos SIM’s additional module, Atmos Surge Analysis can automatically run and generate surge analysis reports which are required in America by the US Department of Transportation (DOT). Such analysis not only fulfils the requirements of the authorities, but also identifies locations where the pipeline is likely to rupture such that preventative actions can be taken.
Atmos Simulation Suite includes
Atmos SIM Online models the pipeline using real time data from DCS and SCADA systems. It allows the operators to monitor areas where there is limited or no instrumentation, such as at mixing points or subsea.
Forecasting modules allow the operators to view the forecasted behavior in the pipeline and assess the safety of the schedule. ‘Look-ahead modelling’ shows what will happen if the pipeline continues to operate in its current state. ‘Predictive modelling’ shows the pipeline’s behavior in a variety of future scenarios that can be configured, saved and used again. Alarms can be configured for a variety of set thresholds to determine if the current schedule is likely to violate safe operating conditions.
Atmos SIM Offline works independently of any real pipeline control systems and is the ideal tool for design, equipment sizing and locating, operational tuning, capacity planning and training. During tuning operations, the tuning assistant automates the tuning process by calculating specified parameters to achieve the correct hydraulic behavior. This ensures the model’s accuracy without the need of intensive tuning performed by the user. The configured model may also be used for online hydraulic simulations if required.
Atmos SIM leak detection module continuously calculates the volume balance. This volume balance is obtained by calculating the total flow into the system minus the total flow out of the system corrected by the inventory changes calculated by Atmos SIM. The volume balance is statistically analyzed by the sequential probability ratio test (SPRT), which calculates the ratio of leak probability over no-leak probability. This ratio is then tested against certain threshold values to provide leak warnings/alarms.
Atmos SIM also monitors the discrepancies between measured and calculated pressures and flows. These discrepancies are processed by the sequential probability ratio test in order to generate reliable leak alarms.
As an additional module to Atmos SIM Offline, Surge Analysis automates some of the analysis procedures and produces a detailed surge analysis report. This would normally be a huge task for a pipeline operator. It conforms to the US Department of Transport (DOT) requirements, identifying locations where the pipeline is most likely to rupture and which operating conditions would be considered safe.
Different options of Atmos Trainers are available to suit each operator’s requirements. Atmos offers everything from a standard Atmos GUI connected to Atmos SIM Offline to a bespoke online trainer fully replicating the SCADA system in line with actual pipeline operations. The latter may even include simulations of emergencies outside the pipeline, such as fire alarms, earthquakes or electrical failures.