Skip to main content

Skip to navigation

Departments & Programs

More

Research

Research over the past decade includes studies of well test analysis of fractured and multiphase reservoirs, design and interpretation of tracer tests in fractured reservoirs, adsorption in vapor-dominated reservoirs, experimental measurements of fluid flow parameters, and optimization of production and reinjection strategies.

Figure 1: Effluent sample containing SiO2 nanoparticles.

Fracture Characterization in Enhanced Geothermal Systems by Wellbore and Reservoir Analysis (2009-2012)

This project will develop systematic techniques and tools to characterize the entire fracture network in Enhanced Geothermal Systems, both in the wellbore and in the reservoir. A complete characterization of fractures in the region both near the wellbore and in the interwell reservoir regions is central to maximizing the efficiency of energy extraction from Enhanced Geothermal Systems. By allowing for the optimal design of the recovery process, the results of this research will permit the energy extraction from a given area of enhanced fractures to be maximized. Given the significant cost of producing an enhanced fracture system in the field, the improvement of energy recovery is a key to making this energy source viable economically.

Figure 1: Permeability of fractures following hydraulic stimulation.  Thick line

Discrete Fracture Modeling of Hydraulic Stimulation in Enhanced Geothermal Systems (2010-2012)

EGS stimulation modeling remains a relatively undeveloped field. There are major challenges associated with modeling EGS stimulation. It involves interacting hydraulic, thermal, mechanical, and thermoelastic processes. It is complicated by the need to account for the complex geometry of the preexisting fracture network.  A handful of individual fracture pathways may take most of the flow between two wells. This study uses discrete fracture networks to tackle the challenges of EGS modeling.

Figure 1: Comparison of the experimental relative permeability with the channel-

Laboratory Measurements of Properties for Steam/Water Flow in Geothermal Rock (2003-2004)

The Stanford Geothermal Program (SGP) has succeeded in making fundamental measurements of steam/water flow in porous media and thereby made significant contribution to the industry by providing both understanding of the phenomena as well as actual parameter value measurements. Two of the important problems left to undertake is the measurement of steam/water relative permeability and capillary pressure in geothermal rock (most of the previous study was conducted in high permeability sandstone as well-controlled test
material), as well as the understanding of how steam-water boiling mixtures flow in fractures.

Figure 3: Examples of gas-water flow channels.

Laboratory Measurements of Properties for Steam/Water Flow in Geothermal Rock (2002-2003)

The main objective is to improve the ability of engineers and scientists to forecast the future performance of geothermal reservoirs. By understanding the production characteristics, development decisions can be made sooner and with greater certainty. This will result in more efficient utilization of the geothermal energy resource. Another objective is to provide engineers and scientists direct methods to estimate the energy production rate of geothermal reservoirs and practical models of steam-water flow properties, including steam-water relative permeability and capillary pressure models.

Figure 1: Steam saturation distribution obtained by using X-ray CT scanner durin

Stream-water Relative Permeability in Geothermal Rocks (1996)

The reliable measurement of relative permeability functions for steam-water flows in porous media is of great importance for reservoir simulation in order to forecast production performance of geothermal reservoirs. Despite their importance, these functions are poorly known due to the lack of understanding of steam-water flows, and to the difficulty of making measurements. Traditionally, these functions are taken directly from isothermal, immiscible gas-liquid displacement processes. However, the use of such functions is not appropriate because these processes do not involve the two important phenomena pertinent to steam- water flows: heat transfer and phase change. Therefore, the objective of this research project is to determine the appropriate relative permeability functions for steam-water flows in geothermal reservoirs.

Figure 1. Temperature vs distance (dimensionless) for injection of liquid from

Boiling and Condensation in Geothermal Reservoirs (1996)

The primary aim of this research project is to gain a fundamental understanding of the controls upon the vaporization of water as it is introduced into a vapor-dominated reservoir and upon the condensation of steam as it moves in a liquid-dominated reservoir. The research is being conducted using both laboratory and theoretical approaches. The results of this analysis will help reservoir engineers to forecast field performance and to estimate likely thermal breakthrough times of injected water.

Optimization of Injection into Vapor-dominated Geothermal Reservoirs considering the Effects of Adsorption (1995)

This research program includes the development of practical reservoir engineering methods to include the adsorption phenomenon in optimization studies of vapor-dominated reservoirs. The investigation has placed specific emphasis on the production and injection characteristics of The Geysers steam reservoir. This analysis will allow improved interpretation of field performance data and aid optimization of future production and reinjection operations.

Figure 1: 3-D Gas saturation distribution obtained by using X-ray CT scanner.

Steam-Water Relative Permeability in Geothermal Rocks (1995)

Reliable measurement of relative permeability functions for steam-water
flows in porous media is of great importance for geothermal reservoir
simulators in order to forecast production performance of geothermal
reservoirs. Despite their importance, these functions are poorly known
due to the lack of understanding of steam-water flows, and the
difficulty of making measurements. Traditionally, these functions are
borrowed directly from isothermal, immiscible gas-liquid displacement
processes. However, use of such functions may not be appropriate because
these processes do not involve the two important phenomena pertinent to
steam-water flows: heat transfer and phase change. Therefore, the
objective of this research project is to determine the correct relative
permeability functions for steam-water flows in porous media.

Boiling and Condensation in Geothermal Reservoirs (1995)

The primary aim of this research project is to gain a fundamental understanding of the controls upon the vaporization (condensation) of water (steam) as it is introduced into a vapor- (liquid-) dominated geothermal reservoir. The research is being conducted using a number of innovative techniques including laboratory and theoretical methods. The results of this analysis will help reservoir engineers to forecast field performance and to estimate likely thermal breakthrough times of injected water.