FTA method for unavailability in gas networks

Contact: Dr. Blazhe Gjorgiev

We have developed a fault tree analyses (FTA) method for the unavailability of supply of gas networks. The method is based on the automatic generation of fault trees, which estimate the probability of disruption of the gas delivery from terminals/storages to the demand nodes. Moreover, it allows probabilistic analyses of the availability of gas supply to individual demand nodes and to the overall the gas network. Furthermore, the developed framework is enriched by steady-state analysis of the gas network operations performed using a physical flow/pressure model. The framework is exemplified with reference to the reduced gas network of Great Britain. The results provide insights to support a robust reliability assessment of the gas network.

Automatic fault tree creation procedure — Graphical representation of the procedure for automatic fault tree creation. “G-i” denotes gate number i, “N-i” denotes the basic event failure of Node i, “L-i-j” denotes the basic event failure of line connecting Node i and Node j, “TER-i” denotes the basic event failure of Terminal i, and “AND” and “OR” are logical Boolean operators.

Critical components in the GB gas system — Representation of the most important components in the network according to: risk achievement worth (left) and risk reduction worth (right). Brighter colors are associated to components with higher importance.