There is low resistivity contrast between reservoir zone and host formation in geothermal fields, especially in areas where the technique of water injection is being carried out. Therefore, in low contrast area, permittivity can be one of the important reservoir indicators besides resistivity. In this study, one EM tomography method of reconstructing the resistivity and permittivity from electr...

In t roduc t ion The F i r s t Stanford Geothermal Reservoir Engineering Workshop was convened i n December, 1975. Its success i n compiling t h e s c a t t e r e d information on geothermal rese r v o i r engineering r e s u l t e d i n i t s es tab l i shment as an annual event of t h e Stanford Geothermal Program. it is appropr ia te t o look back over t h e eff o r t s of t h e p a s t six ...

Reliable and sufficient welltest data is necessary for the evaluation of reservoir properties and well performance. Best results a r e usually obtained by monitoring downhole pressure and flow rate continuously during a transient test. However, a recurring problem for geothermal welltests has been the failure of the downhole pressure instrument in the high temperatures and hostile environments,...

Extensive work has been done in the recent years involving use of conventional and passive seismic data for fracture characterization. This is particularly the case with unconventional reservoirs such as shale gas, shale oil and geothermal fields. The purpose of our study is to combine the benefits of conventional seismic data that provides relatively higher resolution reservoir characteristics...

The existing volumetric approach was honored by considering the effects of oil and gas saturations on the evaluation of geothermal resources in oil and gas reservoirs. The main reason to do so was that oil and gas phases may not be simply substituted by water because the values of the specific heat of oil and gas are smaller than that of water. We selected an oil reservoir, Hexiwu, from Huabei ...

A feature of French geothermal engineering is the development of industrial projects in normal gradient, non-convective areas. The economic feasibility of exploitin producing between 150 and 350 m /h at temperatures from 5 5 O to 85' from depths of 1,500 to 2,000 meters, in sedimentary basins with normal gradient, for direct heat production has been proved by 50 plants providing heating for ove...

A tracer test was carried out in a geothermal doublet system to study the injection behavior of a developed reservoir known to be fractured. The doublet produces about 320 gpm of 160' F heating and then injected; the wells are spaced 250 ft apart. observed in 2 hours and 45 minutes in the production well, indicating fracture flow. However, the tracer concentrations were low and indicated porous...

Heat extraction from deep, hot rocks for energy production is based on water circulation through a man made fracture or natural fractures. As multiple and non-planar fractures in a stress field affect the geothermal reservoir behavior, so the capability to simulate multiple fractures and joints is needed to help reservoir design and operation. A 3D model is developed in this work to simulate an...

Heat extraction mode, e.g. well layout or arrangement of wells, of enhanced or engineered geothermal system (EGS) is crucial to its performance and directly affects its commercial viability. Assuming the subsurface target hot dry rock (HDR) has been well-fractured and the created heat reservoir can be treated as a homogeneous porous medium, we numerically simulate the long-term heat extraction ...

Numerical simulations were carried out to characterize the behaviors of fractured reservoirs under production which causes in-situ boiling. A radial flow model with a single production well, and a two-dimensional geothermal reservoir model with several production and injection wells were used to study the two-phase reservoir behavior. The behavior can be characterized mainly by the parameters s...