The present invention relates to the transport of fluid, such as fuel, over a pipeline and more particularly, to a system and process for delivering contract capacity from two sources along a pipeline to a single end user or target delivery site without violation of prohibitions against forwardhaul-backhaul overlaps at a delivery point and without overlapping main line capacity. Thus, the present invention relates to a new and unique, multi-source, end-user specific, segmentation system and process.
According to current fuel supply protocols, for example for the supply of natural gas, a shipper will contract with a natural gas pipeline transmission company to ship a particular natural gas pipeline capacity on an intra or interstate natural gas pipeline transmission system. More specifically, the shipper/supply company will contract to supply a certain capacity over one or more zones of the pipeline system. That capacity can be segmented into non-overlapping segments along the system so that the contract capacity can be delivered to each of several discreet delivery points. It is generally considered to be outside the contract, however, to overlap delivery to an end user such that contract capacity is exceeded at any point along the pipeline. It is also in general considered outside the contract to deliver contract capacity from two sources, forwardhaul and backhaul, along a pipeline system to a single delivery point.
An exemplary gas pipeline system is illustrated in FIG. 1. As noted above, a shipper will buy a certain capacity from one or more designated zones of a gas pipeline system. The shipper can then deliver the contract capacity to customer(s) along the pipeline in and through those zones. With reference to the exemplary system illustrated in FIG. 1, assuming a customer is located at site X, assuming that the shipper has a source of fuel located at A and a second source of fuel located at B, and assuming that the shipper has bought a certain capacity along the pipeline from A to B, the shipper can transport the contract capacity along the pipeline from A to X or can transport the contract capacity along the pipeline from B to X. As a further alternative, the shipper can transport the contract capacity from source A to customer X and can also transport the contract capacity from source B to customer Y. As long as the shipper ships no more than the contract capacity along any segment of the pipeline system to a delivery point, the shipper will be considered by the pipeline transmission company to be operating consistent with the capacity contract. In this regard, a delivery point along an interstate or intrastate transmission system is a flow meter that is electronically monitored to determine flow at that point. In general a pipeline transmission company would consider it outside the contract, however, to deliver contract capacity from source A to customer X and from source A to customer Y concurrently because this would overlap mainline capacity. The pipeline transmission company would also consider it outside the capacity contract to deliver contract capacity from each of source A and source B to a delivery point at customer X.
It would be desirable to deliver contract capacity from two sources along a pipeline to a single end user or target delivery site. In such a case, the contract capacity with the transmission company could be one half the requirement of the customer.
The present invention provides a system and method for supplying a predetermined amount of fluid, such as fuel and more specifically natural gas, to a target delivery site along at least two pipeline segments wherein a predetermined number of flow meters corresponding to a total of the at least two pipeline segments are provided to meter flow to the site, the predetermined number of flow meters being disposed in parallel for flowing a respective portion of the total flow to the site.
In one embodiment the flow from the at least two pipeline segments is combined upstream of the at least two flow meters and the combined flow is then split into a number of pathways corresponding to the number of flow meters and flowed through the respective flow meters for determining the capacity flow.
In another embodiment, each flow meter is associated with a respective pipeline segment. The outflows from each of the flow meters are then combined for delivery to the site.
As noted above, in the presently preferred embodiment, the fluid flowing through the respective pipeline segments is a fuel and more particularly natural gas. Thus, the fluid flowing through each of the pipeline segments is the same.