Total Base Gas (sometimes called Cushion Gas) is that part of the Total Capacity volume of gas that is intended to permanently remain in the reservoir to maintain reservoir pressure. The Total Base Gas can be subdivided into two fractions: the Native Base Gas and the Injected Base Gas.
The value is reported in MCF (thousand cubic feet of gas).
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U.S. Energy Information Administration, 2004, The basics of underground natural gas storage: U.S. Energy Information Administration Web site, http://www.eia.gov/pub/oil_gas/natural_gas/analysis_publications/storagebasics/storagebasics.html., date accessed, July 21, 2011.