Some pipelines operate at full capacity most of the time. In such cases the operator has little need for accurate demand forecasting and generally aims to push as much gas through the pipeline as possible.

Gas demand forecasting becomes much more important when a pipeline has spare capacity. In this case, the operator has many options when it comes to daily operations. It is a waste of energy to pack the pipeline with more gas than is necessary, both from economical and environmental standpoints. On the other hand, running low on line pack can have some serious consequences when the operator is not capable of delivering the required amount of gas to its customers.

An accurate forecasting tool enables the operator to prepare a pipeline inventory for the upcoming period – typically a few days or up to a week. Ideally, the pipeline should only be packed with sufficient gas to satisfy upcoming customer demand, plus a small safety margin.

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The quality of the forecast is only as good as the quality of the input data and it is important to ensure that all factors that significantly affect gas demand are taken into account by the forecasting tool.

Factors to consider

Line pack management – making sure that the pipeline has sufficient capacity to deliver the requested amount of gas. Cutting a customer short of the contracted volume can have significant economical impacts in the form of penalties.

Gas quality – it is not sufficient to simply deliver the right amount of gas, it also has to be the right quality. To help in this aspect, many operators have real-time, model-based applications that accurately track the gas quality throughout the network.

Weather – extreme or unexpected weather conditions can drastically affect gas demand. Often there are several weather data vendors to choose from, so selecting the most accurate vendor can provide significant benefits.

Maintenance schedules – including planned compressor outages in the forecast is important, so that the true capacity is reflected. If, for example, a specific compressor station is scheduled to be out of service for two days due to maintenance, it might be necessary to pack the pipeline ahead of time to ensure that all customers will receive the needed gas.

There are direct financial benefits of accurately forecasting gas demand for the pipeline operators, as penalties caused by insufficient line pack are minimised or eliminated. Consumers benefit from guaranteed gas deliverability and, in some cases, reduced operating costs that are passed along.

Finally, the quality of the forecasting software applications is important. Accurate transient hydraulic models can significantly help to validate that the upcoming period can be carried out without violating operational and contractual limits.