Pore Network Modeling of Adsorption Effects in Geothermal Reservoirs

Abstract

Physical adsorption is a major factor governing the behaviour of geothermal reservoirs.That is , adsorbed water on the rock surfaces in a geothermal field has been thought to provide a major source of fluid within the reservoir.In addition to this, the effects of carbondioxide flow through water is another main concern for geothermal reservoirs. A single pore model was developed to investigate adsorption considering CO2 presence in water.

Using this model, adsorption effects with CO2 presence is discussed at varying temperature and pressure. The model is run at temperatures ranging between 90-130?C at different relative pressures. Stanford experimental adsorption data were compared to the results of this developed model. It has been found that, there is a reasonable fit between the experimental data and the model. A critical pore radius that allows vapor molecule to enter the pore was calculated. It has been observed that the amount of CO2 adsorped as well as water in geothermal fields is considerable.