Abstract: Proposed Thermal Model for Deep Fresh Water in the Val Verde and Delaware Basins

SWIFT, DOUGLAS B., RICHARD J. ERDLAC, Jr., and JAMES J. REEVES, West Texas Earth Resources Institute, Midland, TX

Recent re-evaluation of the paleo-thermal gradient effecting the Delaware and Val Verde Basins suggests that those gradients may have been significantly higher in the past. Present day bottom hole temperatures well in excess of 100 degrees Celsius suggest the possibility of temperatures sufficiently high for in-situ distillation of fresh water, during intervals of reservoir rupture. It is hypothesized that non-sealing faults may have served as upward conduits of live steam. The anomalous presence of relatively fresh water in Ellenburger strata of the Delaware and Val Verde Basins, as well as in the San Andres on the Central Basin Platform of Crane County preclude sourcing from outcrop. Pressure release along faults bounding live steam reservoirs are hypothesized. This mechanism may explain anomalous fresh water and super-saline concentrations in near adjacent reservoir beds of comparable age. The possibility of future use of large scale, porous reservoirs as low grade geothermal energy sources is discussed. This model opens up the possibility of a number of new fresh water sources in TransPecos Texas. Fresh water, often seen as an inherent barrier to exploration of the western Delaware Basin, may not be a barrier at all.

AAPG Search and Discovery Article #90936©1998 AAPG Southwest Section Meeting, Wichita Falls, Texas