Numerical investigation of production behavior of deep geothermal reservoirs at super-critical conditions

The interplay between collapse structures, hydrothermal systems, and magma intrusions: the case of the central area of Piton de la Fournaise volcano

“…Alternatively, transient-localized decompression produced by water boiling and degassing near active fractures can bring the fluids near-spinodal conditions (Thiéry and Mercury 2009) and induce explosive vaporization. Published simulations of geothermal or volcanic systems (e.g., Yano and Ishido 1998;Hurwitz et al 2003;Reid 2004;Croucher and O'Sullivan 2008;Pashkevich and Taskin 2010) show that these mechanisms are plausible for the case of Piton de la Fournaise. The studies generally stress the necessity to have a medium with a high permeability between the heat source and the fluids' plume to enhance the efficiency of the system.…”

Utilizing supercritical geothermal systems: a review of past ventures and ongoing research activities

“…Ingebritsen et al (2010) provide an overview of numerical modeling of magmatic hydrothermal systems, looking at the transfer of heat and metals from magma bodies into the overlying crust through fluid-rock interaction. Yano and Ishido (1998) utilized the STAR general-purpose geothermal reservoir simulator, incorporating the HOTH2O equation-of-state package, to model flow to a well from a supercritical reservoir, and noted that complex behavior might be expected due to nonlinear changes in compressibility and fluid viscosity. Norton and Dutrow (2001) concurred, suggesting that magma-hydrothermal processes should be thought of as complex dynamical systems whose behavior near the supercritical region is likely chaotic; this is also consistent with the ideas of Fournier (1991), who suggested that zones of increased permeability might be episodic features associated with elevated strain rates.…”

Application of the computer code TOUGH2 to the simulation of supercritical conditions in geothermal systems

“…The problem modelled by Yano and Ishido (1998) simulates the production behaviour of a deep geothermal well at near-critical and supercritical conditions. Fluid is extracted at a constant production rate of 15.7 kg/s, and a 0.9-m radius, enhanced-permeability skin zone, surrounds the well.…”

“…The assumed rock properties are: grain density = 2700 kg/m 3 ; heat capacity = 1000 J/(kg K); thermal conductivity = 2.5 W/(m K). Yano and Ishido (1998) modelled three sets of different initial conditions. The first one fixes the initial reservoir pressure at 30 MPa and investigates the effect of varying the initial temperature, using three cases.…”