Longevity evaluation for optimum development in a liquid dominated geothermal field: effects of interaction of reservoir pressure and fluid temperature on steam production at operating conditions

The steam production rate of a well at fixed operating conditions in a liquid-dominated geothermal field is reduced at first by a decline in reservoir pressure and then by a decrease in fluid temperature, if reinjected water returns to the production well. In many cases, the fluid temperature decrease reduces the steam production rate more than does the reservoir pressure decline. Those effects should therefore be taken into due account in the evaluation of the longevity of an area, because sufficient longevity and recoverable electric energy are the minimum requirements for planning field development.