冰岛深部地热钻探The_WEC_paper_from_Iceland_2007.pdfVIP

13.02.2007 Deep Unconventional Geothermal Resources: a major opportunity to harness new sources of sustainable energy Gudmundur Omar Fridleifsson1), Albert Albertsson2), Bjorn Stefansson3), Einar Gunnlaugsson4), Hakon Adalsteinsson5) 1) Iceland GeoSurvey (ISOR), Grensasvegur 9, 108 Reykjavik, Iceland. 2) Hitaveita Sudurnesja, Ltd., Brekkustig 36, 260 Reykjanesbaer, Iceland. 3) Landsvirkjun, Haaleitisbraut 68, 103 Reykjavik. 4) Orkuveita Reykjavikur, Baejarhals 1, 110 Reykjavik, Iceland. 5) National Energy Authority (Orkustofnun), Grensasvegur 9, 108 Reykjavik, Iceland. ABSTRACT The Iceland Deep Drilling Project (IDDP) is a long-term program to improve the efficiency and economics of geothermal energy by harnessing Deep Unconventional Geothermal Resources (DUGR). Its aim is to produce electricity from natural supercritical hydrous fluids from drillable depths. Producing supercritical fluids will require drilling wells and sampling fluids and rocks to depths of 3.5 to 5 km, and at temperatures of 450-600°C. The long-term plan is to drill and test a series of such deep boreholes in Iceland at the Krafla, the Hengill, and the Reykjanes high temperature geothermal systems. Beneath these three developed drill fields temperatures should exceed 550-650°C, and the occurrence of frequent seismic activity below 5 km, indicates that the rocks are brittle and therefore likely to be permeable. Modeling indicates that if the wellhead enthalpy is to exceed that of conventionally produced geothermal steam, the reservoir temperature must be higher than 450°C. A deep well 3 3 producing 0.67 m /sec steam (~2400 m /h) from a reservoir with a temperature significantly above 450°C could yield enough high-enthalpy ste