The Gas Control Department of an LDC or a pipeline company operates the overall natural gas pipeline system to ensure that safe operating pressures are maintained and customer demand is met. This includes monitoring and control of pipe pressures and flow rates as well as compressors, regulators, valves, odorizers, and storage facilities. There are four primary tasks that Gas Control must complete on a daily basis:
- System forecasts — To prepare for operations, customer usage must be forecast as closely as possible on a day-by-day basis. To estimate usage, Gas Control takes historical and current data (such as weather forecasts, nominations, usage forecasts, storage activity, line pack, as well as any expected maintenance on the system) and runs the model developed by Gas Planning to develop a forecast of how the system will likely be used for up to five days out. Each day this forecast is fine-tuned to get the most accurate picture of what will actually happen on gas flow day. If the forecast indicates an over- or under-capacity situation, the appropriate measures will be put in place to ensure the integrity of the pipeline.
- Development of the operations plan — Next, Gas Control uses their forecast to determine how the pipeline will be used (i.e., how much gas can be scheduled, the appropriate line pack and the pressures required to run the system as planned). This information is then communicated to the various personnel responsible for running the pipeline.
- Implementation, monitoring and adjusting the plan — At the start of the gas flow day, the plan is implemented. Throughout the day, Gas Control monitors system conditions and makes adjustments as necessary. For instance, a malfunction with part of the system or higher or lower usage than expected will alter the pipeline’s plan. Gas Control must react in real time to keep the pipeline operating smoothly. Also, customers may make intra-day nominations that must be evaluated and implemented if accepted.
- Recording actual performance — And finally, Gas Control must record the daily activity on the pipeline. Rarely do customers use the exact amount of gas they had anticipated. And all system conditions such as pressures and flow rates must be recorded for future review. Thus it is important to maintain precise records that account for all the gas on the system.