Assessment of tight gas sands in Cook Inlet Basin

Abstract

The Cook Inlet Basin is the source for all of the natural gas used in south-central Alaska. The estimated ultimate recovery from existing Cook Inlet gas fields is approximately 8.5 trillion cubic feet (tcf) and the proven reserves remaining on January 1, 2004 were 1.8 tcf. It will be difficult to meet the peak demand for gas in south-central Alaska after 2009. Cook Inlet Basin contains vast quantities of unconventional gas resources in tight sands. Resources-in-place and producible gas reserves from the tight sands are unknown. It is likely that these tight sands will be developed as additional gas reserves and will be produced along with the high permeability conventional gas reserves in order to meet both local and export demands. The objectives of this study are to quantify the distribution of tight gas sands; to estimate the resources in place and producible gas reserves in the Cook Inlet Basin; and to predict the post-stimulation gas production. Rate transient analysis, well log analysis and reservoir stimulation analysis were therefore conducted on selected key tight sand wells. Results indicate that the tight gas can play an important role in meeting south-central Alaska's gas demand beyond 2009.