کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6439955 1638332 2015 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Three dimensional conductivity model of the Tendaho High Enthalpy Geothermal Field, NE Ethiopia
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Three dimensional conductivity model of the Tendaho High Enthalpy Geothermal Field, NE Ethiopia
چکیده انگلیسی
Tendaho is one of the high enthalpy geothermal fields at advanced stage of exploration which is located in the Afar Depression in north eastern Ethiopia. Six deep and shallow geothermal wells were drilled in the field between 1993 and 1998. Here we present the first 3D conductivity model of the Tendaho high enthalpy geothermal field obtained from 3D inversion of magnetotelluric (MT) data. MT data from 116 sites at 24 selected periods in the period range from 0.003 s to 1000 s were used for the 3D inversion. The 3D conductivity model reveals three main resistivity structures to a depth of 20 km. The surface conductive structure (≤ 10 Ωm and > 1 km thick) is interpreted as sediments, geothermal fluids or hydrothermally altered clay cap. The underlying high resistivity structure in the Afar Stratiod basalts is associated with the deep geothermal reservoir. At a depth > 5 km, a high conductivity is observed across the whole of the Tendaho geothermal field. This structure is inferred to be the partial melt (heat source) of the geothermal system. The most striking feature in the 3D model is a fracture zone (upflow zone) in the Afar Stratoid basalts at the Dubti area, which acts as a pathway for geothermal fluids. Targeting the inferred fracture zone by directional drilling will likely increase the permeability and temperature of the deep reservoir in the basalts. Hence, the inferred presence of a fracture zone and shallow magma reservoir suggest that there is a huge potential (with temperature exceeding 270 °C at 2 km depth) at Tendaho for conventional hydrothermal geothermal energy development.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Volcanology and Geothermal Research - Volume 290, 1 January 2015, Pages 53-62
نویسندگان
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