In this paper we discuss the basic ideas behind a hydraulically accurate pipeline throughput maximizer. Given a model of the pipeline of interest, a current batch lineup, as well as a batch schedule and a list of scheduled equipment and/or station outages a detailed report on how to run a pipeline in order to maximize and/or verify throughput is generated through a series of successive steady state pipeline/dynamic calculations. Each steady state calculation solves the detailed mass, and momentum balances along with a dynamic accounting method that handles the energy balance, and determines a valve and pump line up that will maximize the product throughput on the line. The pipeline is assumed to remain in this steady state flow configuration as the simulation steps forward in time until the next event—such as a planned outage, or new incoming batch enters the pipeline—at which time a new solution is computed. To account for thermal transients that could occur during the event interstitials, a method for handling heat transfer in such a steady state is presented. The result of such calculations is a series of pump and valve line ups, along with associated pipeline flows, pressures, linefills, and various component physical properties during each new period carried forward for an arbitrary amount of time, typically one month or less. Given the partial steady state nature of the calculations, the time requirement to simulate an entire months' worth of data is on the order of minutes.
Understanding the current conditions in an oil or gas pipeline is critical for its day-to-day operations; understanding its medium term capabilities also must be considered by pipeline managers to successfully plan operations for days, weeks, and months to come ensuring smooth day-to-day operations and ensuring deliveries arrive as promised.