Abstract: Evaluating Fluid Flow Around the Danbury Salt Dome, Brazoria County, TX

GELL, CHRISTIANNE M., and R. M. CAPUANO, University of Houston, Dept. of Geosciences, Houston, TX

Fluid flow around salt domes is important in the petroleum industry because many salt domes have a narrow ring of hydrocarbon production around them. This research evaluates fluid flow around the Danbury Salt Dome, located in an overpressured sedimentary basin, Brazoria County, Texas. Analyzing the chemical constituents of oil and water wells around the salt dome will aid in determining the source of salt in the brines, ultimately leading to the origin of each of the waters: oceanic water, fresh meteoric groundwater, water that has upwelled from the overpressured section, or one of these sources altered by halite dissolution or recrystallization. Information on fluid sources will then be used to predict fluid flow associated with the dome.

Fluid samples were collected from 17 oil and 4 water wells within 5 km of the Danbury Salt Dome. The wells range in depth from 0.1 to 2.7 km. The samples are being analyzed for: conductivity, total dissolved solids, pH, H[2]S, Na, K, Ca, Mg SiO[2], Al, Fe, SO[4], CO[3], HCO[3], B, Sr, CH[3]COO, F, Cl, Br, I, dD and dO¹⁸. Br, I, Cl, dD and dO¹⁸will be used as natural tracers to predict fluid migration in the area by identifying the source of water and mixing relationships.

Total dissolved solids of the oil well samples vary between 63,000 to 131,000 mg/l and show no correlation with depth. Other chemical analyses are in progress.

AAPG Search and Discovery Article #90931©1998 AAPG Foundation Grants-in-Aid