As described in PSIG paper 1613, PG&E's Batch Analysis Tool (BAT) allows a planning engineer to run hundreds to thousands of simulations automatically and sequentially rather than manually, one run at a time. This functionality greatly increases efficiency and allows for thorough analyses of all potential scenarios. This paper will present an actual use case study where BAT was utilized to perform over 6,500 simulation runs to gain system intelligence, optimize operations and gain customer reliability information for a multitude of operating scenarios for 256 combinations of system operating restrictions.
As the location of the San Bruno pipeline incident, PG&E's Peninsula Local Transmission (LT) System has a high level of safety focus and activity.[1] In-line inspection (ILI), strength tests, pipeline replacements and automatic and remote control valving projects result in system outages throughout the year. In addition, ILI's and strength tests can result in pressure reductions, and/or pipeline sections being isolated, which can significantly reduce capacity and the ability to meet customer demand. Customer service reliability is of particular interest for pressure reductions or operating restrictions that may occur during the high demand winter heating season.
This paper will present the use of the BAT in an actual study performed on the Peninsula LT system. Five major sections of the gas system faced potential operating restrictions resulting in 256 operating restriction scenarios. Each operating restriction scenario was analyzed at various temperatures, and at various operating configurations (pressure set points, cross-tie operations, interruptible non-core customer curtailments, use of portable Compressed Natural Gas (CNG) or Liquefied Natural Gas (LNG), and modeling uncertainty). In only 59 hours the BAT technology was used to complete an extensive and complex hydraulic analysis of 6,500 runs. Performing the analyses without BAT, manually a single run at a time, would have taken weeks and only yielded a fraction of the runs and system intelligence. The expansive analysis identified the most impactful operating restrictions, the best ways to operate under the restrictions, and the time of year the system would be most at risk of not meeting demand. This paper will illustrate how the power of the technology used to rapidly perform hundreds to thousands of runs provides critical system intelligence, optimize operations to maximize capacity and improve customer service reliability and fully understand operational risks when making key decisions on proceeding with the safety work.