When liquid is injected into a geothermal reservoir, a fraction of the liquid may vaporise if the reservoir is sufficiently hot. The vapour forms at an approximately p1ana.r liquid-vapour interface and diffuses towards the far boundary of the reservoir. If vapour is extracted froin the far boundary, then once the new vapour has diffused across the reservoir, the rate of production of vapour at ...

Fluid flow and tracer transport in a fractured Bot Dry Rock (HDR) geothermal reservoir are modeled using fracture network modeling techniques. The steady state pressure and flow fields are solved for a two-dimensional, interconnected network of fractures with no-flow outer boundaries and constant-pressure source and sink points to simulate wellbore-fracture intersections. The tracer response is...

The optimal design of production in fractured geothermal reservoirs requires knowledge of the resource’s connectivity, therefore making fracture characterization highly important. This study aims to develop methodologies to use resistivity measurements to infer fracture properties in geothermal fields. The resistivity distribution in the field can be estimated by measuring potential differences...

Information on the distribution of permeability at depth is of primary concern in geothermal reservoir engineering. Based on a tracer circulation test performed at the European Enhanced Geothermal System (EGS) test site at Soultz-sous-Forêts, France, three different inversion methods are applied and studied with respect to their potential for estimating the permeability distribution: A fully ph...

The conversion efficiency of geothermal power developments is generally lower than that of conventional thermal power plants. Confusion can be found in literature concerning the estimation of this conversion efficiency. Geothermal power plants conversion efficiency estimates that is based on the enthalpy of the produced geothermal fluid can be the most desirable for use during the first estimat...

We have extended our “EKP-postprocessor” (Ishido and Pritchett, 1996) to calculate electrokinetic potentials in fractured geothermal reservoirs that are represented computationally as “MINC” doubleporosity media. In such reservoir descriptions, global mass exchange between adjacent macroscopic computational grid blocks takes place mainly through the “fracture zone”. Inter-block flow through the...

In this work, the hydrogeochemistry and environmental isotopic compositions of thermal and mineral springs in Arxan, northeastern China, were used to assess the genesis of the thermal system hosted by deep-seated faults. The reservoir temperature was calculated using the mineral saturation index and geothermometers. According to isotopic analysis, the spring water was of meteoric origin. Sixtee...

We have refined a method used previously by several authors to estimate water-steam relative permeabilities. Our version provides also reasonable estimates of the corresponding saturations. It relies on production output data obtained by means of short tests. This constitutes a distinct advantage over the previous variants, which require long-term production data, because it allows early accura...