Tennessee Gas Pipeline's Gas Control and Technical Operations Groups have been experimenting with Expert Systems since 1995. The engineers and technicians have successfully developed rules and procedures in an expert system language that recognize inconsistent data and replaces it with more reliable information, as well as providing the gas controllers with recommendations to improve pipeline operation. Concurrent to the expert system development, the Operations and Transportation Planning groups have been developing steady-state and real-time pipeline simulators that predict the pipeline operation, empowering the engineers and controllers to develop new methods of transporting gas efficiently. The pipeline simulator also features look ahead run engines that enable the modeler to evaluate probable outcomes of various operating scenarios. This paper will examine the integration of an expert system and a pipeline simulator by:
Defining the scope of the expert system and pipeline simulator
Diagramming the data flow from the SCADA system to the expert system
Describing how the expert system, using rules and procedures created by the controllers and engineers, creates the input data for the pipeline simulator
Providing examples of using the data from the pipeline simulator to feed the expert system to optimize the pipeline configuration
Using the expert system as a focal point
for sharing the SCADA data, pipeline simulation results and the economic possibilities of various operations Finally, we will propose a closed loop process in which the pipeline simulator receives its initial state from the expert system. The pipeline simulator would in turn feed the data back to the expert system for analysis and recommendations based on the controllers pipeline knowledge. The combination of an expert system and a pipeline simulator could yield an unprecedented level of operational efficiency. It is the goal of this paper to provide insight into the application of the two systems working together.
ExSys. 2Expert System removes erroneous SCADA data points from the data stream and passes the data to the Pipeline Simulator, PLSim, which computes the fuel consumption for a variety of operating options, and 3returns the theoretically optimized solution to the Expert System. 4The power and gas prices from the marketing system are used with, the station selection from the pipeline simulator, to compute actual and future theoretical operating costs. 4aThe processed information from the expert system is sent to a historical database for long term storage. 5The Expert System displays the combination of the Pipeline Simulation data and the processed SCADA data. 1aThe raw SCADA data is also stored in the historical database for audit purposes and for evaluation, to verify that the processed data was accurately scrubbed by the expert system. The ExSys and PLSim Integration - 2nd Generation Most companies have detailed PLSim models. What if the ExSys could be built from an existing PLSim model? The PLSim models used by Tennessee Gas Pipeline, were developed over a period of several years.