Study on deep geothermal drilling into a supercritical zone in Iceland

Abstract

Practical and environmental reasons will call for increasingly deeper drilling for exploiting high-temperature geothermal fields in the 21st century. The Icelandic geothermal community is planning a joint deep geothermal drilling research project, ICELAND DEEP DRILLING PROJECT (IDDP), on the Reykjanes peninsula - the landward extension of the Reykjanes Ridge. The principal aim is to bring supercritical hydrous fluid (400-600 C) up to the surface under high pressure, through a 4-5 km deep drillhole, into a research pilot plant where the thermal energy of the fluid is used and the chemicals extracted. When drilling into supercritical conditions, many problems may occur due to severe conditions related to increasing well depth and rising temperatures and pressures, so new advanced technology is needed. If successful, the technical gain from deep drilling and research could have a global impact on future geothermal utilization.