Maximizing benefits from a real-time based predictive model requires that the same be used continuously and consistently as an operations aid. Many routine but important operational questions require analyses of multiple operating scenarios, to select the most appropriate one amongst them. Even with the robust hydraulic simulation engines and their associated GUI available today, carrying out the required analyses becomes a time consuming and tedious task. A viable alternative would be to provide "intelligence" within the simulation software such that these questions can be answered in an automated mode.
Recognition of the role of hydraulic simulation software, for both the design and operation of pipeline systems, has grown over the years. In the operational context, the ability of real-time models to "track" fluid behavior in the system, for all hydraulic variables of importance and at all points along the system, has gained significant recognition. Benefits of predictive simulations, commencing from either the current real-time state or a hypothetical starting state for the pipeline system, for the purposes of operating the system with higher degrees of safety and efficiency, is also gaining wider acceptance. Recognition of the benefits of predictive simulations as training tools for operators is apparent from the recent legislative thrust to make such training a requirement. Part of the phenomenon of increased acceptance of hydraulic simulation software is a reflection of the robustness and accuracy of commercially available simulation engines. Another important contributing factor to this increased use and acceptance has been the development of Graphical User Interfaces (GUI) by software vendors. The easy and visual interface and access to the hydraulic engine provided by the GUI, compared to the keyword files that existed earlier, has permitted greater and more effective use of the software by personnel not intimately associated with the hydraulic simulation engines or their keyword controlled command language structures. While the task of using these simulation tools in practical contexts has indeed been made easier by the current hydraulic engines and associated GUI, provision of timely answers to many important but routine operational questions nevertheless remain a challenge. Examples of typical questions that fall in this category include:
Given the current state in the pipeline system, anticipated short term weather conditions and equipment availability projections, what is maximum throughput (system capability) possible by a given time?
Given the current state in the pipeline system, specified delivery nomination that has to be met during that day, anticipated short term weather conditions and equipment availability projections, what set of station discharge pressure set points will lead to a "balanced" operation in the system? In this context, the term ‘balanced’ implies that all compressors are utilizing approximately equal percentages of their maximum power. For "bullet line" transmission systems, such balanced operation generally translates to conditions wherein the least amount of fuel gas is used to meet the specified delivery nomination. Such operation also has the benefit of being more robust for the purposes of handling unscheduled equipment outages.
