Geothermal Energy for New Mexico: Assessment of Potential and Exploratory Drilling

[摘要] This report summarizes the drilling operations and subsequent interpretation of thermal and geochemical data from the New Mexico Tech NMT-2GT (OSE RG- 05276 POD) test well. This slim hole was drilled along an elongate heat-flow anomaly at the base of the Socorro Mountains to better assess the geothermal resource potential (Socorro Peak geothermal system) on the western side of the New Mexico Tech campus in Socorro, New Mexico. The reservoir depth, hydraulic properties, temperature and chemistry were unknown prior to drilling. The purpose of the NMT-2GT (OSE RG-05276 POD) well was to explore the feasibility of providing geothermal fluids for a proposed district space heating system on the New Mexico Tech campus. With DOE cost over runs funds we completed NMT-2GT to a depth of 1102 feet at the Woods Tunnel drill site. Temperatures were nearly constant (41 oC ) between a depth of 1102 feet. Above this isothermal zone, a strong temperature gradient was observed (210 oC /km) beneath the water table consistent with vertical convective heat transfer. The existence of a groundwater upflow zone was further supported by measured vertical hydraulic head measurements which varied between about 258 feet at the water table to 155 feet at a depth of 1102 feet yielding a vertical hydraulic a gradient of about 0.1. If the upflow zone is 1 km deep, then a vertical flow rate is about 0.6 m/yr could have produced the observed curvature in the thermal profile. This would suggest that the deep bedrock permeability is about 20 mD. This is much lower than the permeability measured in a specific capacity aquifer test completed in 2009 within fracture Paleozoic sandstones near the water table (3000 D). Flow rates measured during drilling were measured using a v-notch weir. Flow rates were consistently around 1000 gpm. While the temperatures are lower than we had anticipated, this geothermal resource can still be developed to heat the NM Tech campus using heat pump technology.

[发布日期] 2010-02-17

[学科分类] 再生能源与代替技术

[关键词] AQUIFERS;CAPACITY;CHEMISTRY;DRILLING;EXPLORATORY WELLS;FLOW RATE;FRACTURES;GEOTHERMAL ENERGY;GEOTHERMAL FLUIDS;GEOTHERMAL RESOURCES;GEOTHERMAL SYSTEMS;HEAT FLUX;HEAT PUMPS;HEAT TRANSFER;HYDRAULICS;PERMEABILITY;SANDSTO