Mount Elbert Methane Hydrate Site (or Mount Elbert Gas Hydrate Test Well, Mount Elbert test well) Site Highlights First dedicated gas hydrate stratigraphic test well on the Alaska North Slope; First application of extended duration, open-hole wireline pressure testing using Modular Dynamics Testing in a gas hydrate-bearing reservoir; 504 feet (154 m) of core collected (100 feet (30.5 m) hydrate bearing); Confirmation of the existence of 60–75% hydrate saturation within reservoir quality sands in target intervals; Validation of methods used to identify potential hydrate occurrence; Confirmed the formation's ability to produce gas from hydrate through pressure reduction; Well data enabled reservoir modeling simulations of a heterogeneous, complex natural gas hydrate-bearing reservoir system at the well and field-scales. Introduction to the Area The Alaska North Slope region (ANS) is largely known for its remote Arctic wildlife and setting, and prolific petroleum production from the Prudhoe Bay oil fields. However, natural gas hydrate accumulations on the North Slope are increasingly the focus of energy resource and climate studies, both of which seek to understand how much hydrate is located within this region and how those deposits may respond to natural and/or induced changes in pressure and/or temperature. The North Slope region lies north of the Brooks Range and is bounded by the Beaufort and the Chukchi Seas to the north and west, and the Canada–US border to the east. While the ANS is remote, recent research in the region has offered groundbreaking insights concerning the potential to predict and identify significant occurrences of natural gas hydrates (NGH) in subsurface reservoirs, as well as its future production potential. General physical and geological description The Alaska North Slope region was identified by the USGS as an important hydrate-bearing region in the United States. Current USGS estimates indicate ~ (Tcf) of technically recoverable gas resources from hydrate accumulations in this region. Drilling within the greater Prudhoe Bay region has enabled the delineation and evaluation of two trends in particular that have been the focus of recent studies, the Eileen and Tarn trends. The Eileen trend was first indicated by dedicated gas hydrate evaluation conducted in the Northwest Eileen State #2 exploration well in 1972 by Arco and Exxon. Evaluation of data from hundreds of industry well logs enabled Collett to identify a number of extensive gas hydrate-bearing sand horizons that occurred largely below the base of permafrost. Subsequently, drilling problems with the 1991 Cirque-1 well