Distributed parameter models for the Svartsengi geothermal field, SW-Iceland and the Yangbajing geothermal field, Tibet, China

Abstract

This report describes distributed parameter models of two geothermal reservoirs. The basic equations of the problem are derived and the reservoir behaviour of two different geothermal fields is analyzed. The first field is the Svartsengi geothermal field in southwest Iceland. For this well-developed geothermal field, a lot of data collection and analysis has been carried out during the last seventeen years. The calibration in this report is to match the water level drawdown measurement in several wells. The obtained reservoir parameters confirm the former research work in this field. The second field is the Yangbajing geothermal field in Tibet, China. Similar to the Svartsengi geothermal field, it is also liquid-dominated system with a two-phase zone on the top. Despite insufficient time-dependent production data and continuous water level measurement in observation wells, the obtained reservoir parameters were used to predict the response of the reservoir in the future. If production is increased from 200 to 550 kg/s, the future water level drawdown is predicted to increase quickly. Therefore, the influence of two different reinjection schemes has also been taken into account, including the subsequent temperature decline due to reinjection.