Within the Kenai Gas Field, Tyonek Gas Pool 1 is defined as the accumulation of gas common to and which correlates with the accumulation found in the interval 9155' to 9890' in the Kenai Deep Unit No. 1 well. This pool was discovered on October 11, 1959 by the Kenai Deep Unit No. 1 well, and regular gas production began in March 1968 from Kenai Deep Unit No. 1. Production peaked at an average daily rate of 52,381,000 cubic feet per day in February 1979 from 3 production wells and then began to decline. During 2009, one additional new well, Kenai Deep Unit No. 9, was drilled, briefly increasing production. During April and May of 2011, only the Kenai Deep Unit No. 1 well produced gas from this pool, averaging 1,985,000 cubic feet per day. Prior to 1980, 8994 barrels of oil were reportedly produced from this pool by the Kenai Deep Unit No. 1 and No. 4 wells.

The Kenai Gas Field structure consists of an asymmetric anticline that trends north-south that lies about 5 miles south of the City of Kenai. The axis of this anticline is parallel with, and about 1 mile east of, the eastern coastline of the Cook Inlet. The shallowest perforated interval in the Tyonek Gas Pool lies 8760 feet below sea level in the Kenai Deep Unit No. 1 well.

 

In the Kenai-Cannery Loop area, the Miocene-aged Tyonek Formation comprises thick (up to 40 feet or more) sandstones and conglomeratic sandstones of good reservoir quality that were deposited by larger, meandering streams within a poorly drained alluvial plain. These sandstones are well consolidated, quartz-rich, feldspathic litharenites and sub-litharenites. Although these sandstones contain clay and calcite cement, their effective porosities range up to 12 percent and permeabilities may exceed 50 millidarcies. Coal beds are also present, especially in the deeper portions of the pool, where they may reach more than 20 feet in thickness.