| Title | Geothermometry and Shallow Circulation of a Low Enthalpy System: The Bath Geothermal Reservoir, Jamaica |
|---|---|
| Authors | DeBonne N. WISHART |
| Year | 2013 |
| Conference | Stanford Geothermal Workshop |
| Keywords | geothermometry, hydrogeochemistry, geothermal, thermal springs, Jamaica. |
| Abstract | Geothermometry was applied to the thermal fluid discharges from fractures at the Bath hot springs to estimate the temperature of the geothermal reservoir expected to be encountered by drilling. Bath is situated in Jamaica’s most seismically-active region. Na-K geothermometers estimate reservoir temperatures at 83°C-102°C compared to geotemperatures of 80°C-83°C estimated from silica geothermometers. The ä2H–ä18O relationship of surface discharge temperatures indicate shallow mixing and the influence of saline geothermal source. The depth to circulation is estimated to be between 1 – 1.8 km. SiO2/Cl and B/Cl relationships suggest the existence of a low enthalpy geothermal system. A comparative interpretation of the results of thermal discharges from springs of central Jamaica shows Bath has the greatest geothermal potential and warrants hydrogeophysical exploration to target the region for shallow well drilling and geothermal energy generation. The total stored heat (E) is 1.54 x 1015 J with a determined reservoir thickness of 0.4 km, an area of 3 km2, and 25 years of production. The total reserve in the Bath geothermal system is 33.83 MWe with a power capacity per km2of 13.54 MW. A hydrogeological conceptual model for the geothermal reservoir is proposed based on hydrogeochemical, geological, structural, and isotopic data. |