This book contains the proceedings of NATO Advanced Study Institute, 'Underground Storage of Natural Gas - Theory and Practice', which was held at The Middle East Technical University, Ankara, Turkey during 2-10 May 1988. Underground storage is the process which effectively balances a variable demand market with a desirably constant supply provided by pipelines. Storage reservoirs are the unique warehouses designed and developed to provide a ready supply of natural gas in response to high, peak demands during cold weather. The natural' gas is injected into the underground storage environment...