Nissen, Susan E.1, W. Lynn Watney1, Saibal Bhattacharya1, Alan P.
Byrnes1, David Young1
(1) Kansas Geological Survey, University of Kansas, Lawrence, KS
ABSTRACT: Geologic Factors Controlling Natural Gas Migration from the Yaggy Underground Gas Storage Site, Kansas
In January 2001, explosions and eruptions of gas geysers occurred in the city of Hutchinson, Kansas. Three days earlier, an estimated 143 million cu ft of natural gas at high pressure escaped from a casing leak at the Yaggy underground gas storage facility, 7 miles to the northwest. At Yaggy, natural gas is stored in solution caverns in the Lower Permian Hutchinson Salt. The casing leak was located just below the top of salt and 184 ft above the top of the storage cavern. Vent and observation wells drilled in the area after the explosions encountered gas over a distance of 9 miles, primarily along a narrow, northwest-southeast-trending corridor between Yaggy and eastern Hutchinson. The widespread distribution of gas warranted further characterization of the surrounding geology to resolve features that provided pathways for the gas. Studies of 116 borehole logs in a 150 mi2 area, along with seismic lines, core, well logs, and shut-in pressure data, suggest that gas moved through the area within a thin dolomite interval 170 ft above the top of the Hutchinson Salt, apparently along a fracture cluster that follows the crest of a low-relief, westerly plunging anticline. High-resolution seismic and stratigraphic analyses revealed deep-seated structural features that appear to have controlled fracture and fault concentrations in the thin, brittle dolomite beds that served as the conduits for the gas. Episodes of focused meteoric water circulation along associated fractures apparently resulted in evaporite dissolution that enhanced structural relief and tensional forces along the anticline.
AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.