Geothermal Resource Assessment of Gueydan Dome, Vermilion Parish, Louisiana

Gray, Taylor A.¹; Nunn, Jeffrey A.^1
1 Geology and Geophysics, Louisiana State University, Baton Rouge, LA.

The high thermal conductivity and vertical geometry of salt domes in South Louisiana have the potential to be a economic source of geothermal energy. The Gueydan dome of South Louisiana is a piercement salt diaper lying along the Vermilion and Acadian Parish border. The shallowest salt encountered is at a depth of 4,790 feet, and the surrounding strata are Cenozoic sand and clay deposits. Previous geothermal assessments in the vicinity conducted in the 1970s and early 1980s selected prospect locations off the east and south flanks of the dome. This study assesses the economics of reservoirs to the north and west of the dome where existing oil and gas wells are in the mature stages of production. The two target reservoirs are the Camerina "A" sand and the Alliance Sand. A well drilled southeast of the dome intersected the Camerina "A" sand at 15,886 feet where formation temperatures reached 360 degrees Fahrenheit. The Alliance sand is an excellent reservoir with 600 millidarcy permeability and 28 percent porosity. Isotherms indicate a thermal anomaly at the crest with formation temperatures at 144 degrees Fahrenheit recorded at 4,372 feet. This temperature is above the average geothermal gradient for the Gulf Coast, but not high enough to be considered an economic resource for geothermal energy. Using shallow temperatures as a constraint, numerical modeling of the thermal regime and an economic evaluation will be conducted to indicate prospect locations at greater depths along the flanks of the dome.

AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009