MT in geothermal area
Han-Lun, Hsu
Abstract
In previous studies we know that temperature and permeability are some of the parameters controlling electrical resistivity. In the geothermal area, we can see the high temperature and sometimes contained water. Because electromagnetic methods can provide a model of the subsurface relating changes in the resistivity to changes, electromagnetic methods are efficient geophysical methodology to explore deeper part of the geothermal field. Of all the EM methods, MT metohdseems the most appropriate to see the deep depth. Due to the nature source, MT has good depth penetration and has been applied to the determination of the deep structures. After processing MT data with tensor analysis, we can get the information of EM strike and 3-D effects for approximate 2-D imaging, and then the results for 2-D inversion can make a good imaging to show the electrical resistivity. Then theinterpretation revealed a goodcorrelation between the features of the geothermal field andresistivity distribution at depth.In particular,the several imagings show good conductive zonein the deep depth and its relation to the main geothermal region. So that we can make sure the MT method in geothermal is useful for explaining the geothermal reservoirs.
Reference
Bai, D., Meju, M.A., Liao, Z., 2001. Denghai Bai, , Maxwell A. Meju and Zhijie Liao, 2001. Magnetotelluric images of deep crustal structure of the Rehai geothermal field near Tengchong, southern China, Geophys. J. Int. 147, 677–687
Harinarayana T., Abdul Azeez, K.K., Murthy, D.N., Veeraswamy, K., Rao, S.P. Eknath, Manoj, C., Naganjaneyulu, K., 2006. Exploration of geothermal structure in Puga geothermal field, Ladakh Himalayas, India by magnetotelluric studies, Journal of Applied Geophysics, 58, 280-295.