Titill:
|
Geology and gradient wellsGeology and gradient wells |
Höfundur:
|
Kristján Sæmundsson 1936
;
Geothermal Development Company Ltd.
;
KenGen
;
Jarðhitaskóli Háskóla Sameinuðu þjóðanna
;
United Nations University
;
United Nations University, Geothermal Training Programme
|
URI:
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http://hdl.handle.net/10802/12844
|
Útgefandi:
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United Nations University
|
Útgáfa:
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2016 |
Ritröð:
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United Nations University., UNU Geothermal Training Programme, Iceland. Short Course ; SC-21 |
Efnisorð:
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Jarðfræði; Jarðhiti; Jarðhitaleit; Borholur; Hitastigull
|
ISSN:
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1670-794x |
Tungumál:
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Enska
|
Tengd vefsíðuslóð:
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http://os.is/gogn/unu-gtp-sc/UNU-GTP-SC-21-0305.pdf
|
Tegund:
|
Tímaritsgrein |
Gegnir ID:
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991008405539706886
|
Athugasemdir:
|
Presented at Short Course X on Exploration for Geothermal Resources, organized by UNU-GTP, GDC and KenGen, at Lake Bogoria and Lake Naivasha, Kenya, Nov. 9-Dec. 1, 2015. |
Útdráttur:
|
Drilling of gradient wells is a method used in exploration of both high- and lowtemperature geothermal fields. The applicability of the method depends on the permeability of the subsurface rock and the depth to groundwater. Low permeability is a prerequisite for the method to give reliable results because it is very important to avoid disturbance from internal flow of water inside wells. The drilling depth is accordingly anywhere from a few tens of metres to a few hundred metres. The latter may be necessary in areas of young or unaltered volcanics and low ground water level (such rocks are also as a rule costly to drill and secure from caving in). In fracture controlled low-temperature fields shallow boreholes come out best. This method has been applied also in high-temperature geothermal fields both as a regional survey and as testing the validity of indirect evidence (from geology or resistivity) of a potential. It is clear that knowledge of the hydrological conditions of the prospect area is needed, and also familiarity with the basic principles of hydrogeology. |