Yellowstone National Park, USA, has more than 10,000 thermal features throughout a land area of 2.2x10 acres (just short of a million hectares). These characteristics make it unique among the world’s geothermal areas and, consequently, it has been the subject of numerous geological, geochemical, and ecological studies. Past and current research related to arsenic in the thermal waters of Yellow...

A concept of "Fractal Fracture Mechanics" for HDR .(Hot Dry Rock) geothermal reservoir design has been developed as an extension of conventional rock fracture mechanics. It is suggested that this concept is successfully applicable to characterize and model subsurface fracture network in HDR geothermal reservoir. Furthermore, this modeling procedure makes it possible to evaluate the thermal ener...

Abstract Steam-water capillary pressure is often either ignored or determined artificially in geothermal reservoir engineering. However steam-water capillary pressure plays an important role in geothermal reservoir performance and may not be substituted by air-water capillary pressure. To this end, preliminary mathematical models have been developed to calculate drainage and imbibition steam-wa...

Modeling carried out using a super-critical version of TOUGH2 has been used to investigate different source models for the geothermal fields in the Taupo Volcanic Zone (TVZ), New Zealand. The models describe the cooling, by groundwater circulation, of magmatic intrusions into the upper 8 km of the crust. By comparing the calculated surface heat flux from these intrusions with actual thermal out...

Geothermal solid wastes such as scale and sludge from the Philippines and Mexico containing Cu, Zn, and Pb at levels above earth's crustal abundance were studied for their acidification potential if disposed in a landfill. A batch reactor technique using the iron and sulfur oxidizing bacteria ThiobaciZlus ferrooxidans was developed for geothermal wastes to predict their acid mine drainage and b...

Increasing attention has been given to energy utilization in Turkey. In this report, we present an energy efficiency evaluation and economic feasibility analysis of a geothermal heating and cooling system (GSHP) and a mechanical compression water chiller system (ACHP) to improve the energy utilization efficiency and reduce the primary energy demand for industrial use. Analyses of a mechanical w...

A geothermal direct-use project utilizes a natural resource, a flow of geothermal fluid at elevated temperatures, which is capable of providing heat and/or cooling to buildings, greenhouses, aquaculture ponds, and industrial processes. Geothermal utilization requires matching the varied needs of the user and characteristics of the resource in order to development a successful project. Each appl...

Estimates for the pressure decline in high TDS geothermal fluids containing dissolved gases are extremely sensitive to the PVT representation of the reservoir fluid. Significant errors in predicted pressures will occur if the geothermal fluid is represented by one or two pseudo components with modified water properties. As a result, we have developed a PVT model to predict the thermodynamic pro...

The geochemical characteristics of the hot spring waters in the Rehai and Ruidian geothermal fields, Tengchong County, Yunnan Province, China, are described and their possible environmental impact assessed. The results show that the alkaline spring waters contain high levels of K, Na, F, Cl, SiO2, whereas the only acidic spring water in Rehai geothermal field contains high levels of SO42−, Mn a...

A thermodynamic approach is presented to classify geothermal reservoir as vapor or liquid dominated. According to it, the vapor dominated reservoir has specific volume of fluid (i.e. combined vapor and liquid) greater than the critical volume of water whereas the liquid dominated reservoir has lesser specific volume. Enthalpy is not a conservative entity in a geothermal system. Apart from it, t...