This paper addresses gas nominations and allocations in gas transmission networks. An integrated system is designed to use both the current state of the network and the operational schedule to verify the feasibility of each Shipper's nomination. After the description of the gas management system, a case study will be used to demonstrate the integrated application of the gas management system and the on-line models to an operational pipeline network. The applicability of the integrated approach to other networks will then be addressed together with its potentials and limitations.
Gas Management System.
Rate in Force.
Producers: entities that have gas reserves.
Consumers (also "Offtaker"): entities that have gas demand.
Shippers: dealers or brokers of gas who broker transactions between the Producers and the Consumers. Shippers may also trade allocated capacity with other Shippers. A Shipper can request a series of nominations for registered consumers. A consumer is serviced by a single Shipper.
Transporter: operator and maintainer of the pipeline network - PGN (PT Perusahaan Gas Negara Tbk) in the case study.
Receipt Point Operators: parties who are responsible for defining the pipeline control settings to meet the requested Rate in Force ("RiF") for all contracted Shippers.
Billions of British Thermal Unit (BTU). A BTU is the amount of heat necessary to raise one pound of water by 1 degree Farenheit (F). 1 British Thermal Unit (BTU) = 1055 J.
As the demand for gas increases continuously and government authorities de-regulate in many countries, pipeline operating companies are facing increasing challenges. Many companies are now using computer software systems to help pipeline operators to manage their complex networks with multiple demands, (Ref [1], [2], [3], [4]). Recently, government authorities have recently started to specify Gas Management Systems as part of the approval requirements for constructing and operating gas transmission pipelines. For example, in Indonesia, the Transporter was requested to procure and operate a GMS (Ref [5]). Not only is the GMS required to manage daily nominations, it has to accurately model the pipeline transients and dynamics. This requirement made it necessary to develop a GMS that meets all the rules specified in the Pipeline System Rules (Ref [1]) and is fully integrated with a hydraulic simulation package. In the following sections the GMS is described in detail and its application to the gas transmission network is discussed. The paper then closes with the conclusions section.
An on-line pipeline hydraulic modeling system is an excellent tool for calculating and reporting the current (or future) state of a gas pipeline network. The primary function of the GMS is to superimpose onto this model a system of contractual rules, and an awareness of the current status and future requirements of individual stakeholders within the system. It also acts as the primary reporting system, and the real-time messaging manager.
