| With the increaseing in green energy, the geothermal resources receive every country’s more and more attention in the world. They become the object of development and research. Our country is the one who are consuming the energy very much and it is a large country which has a lot low-temperature geothermal resources. Through the geological investigation, we found more than three thousands geothermal anomalies. And we have already made geothermal exploration and evaluation for more than50of them. We have already built more than2,000geothermal wells in our country. And the total use of geothermal resources has been ranked first in the world.In the total geothermal resources of our country, Conductive geothermal field in sedimentary basins occupies a large proportion. This kind of geothermal field is always buried deeply and has a low temperature.And the essay firstly direct the magnetotellurics’basic qualities,studying about the resistivity of common rocks and also do analysis in influential factor of resistivity like rock type、rock gap、water-bearing and the effect of Ground Temperature Field gasping the moment geothermal studying.Also,we give a calculation methods of Earth Temperature Gradient and resistance measurement. After introducting the interplay between radiation and medium, it following present the background and current status of the CSAMT.Then the article implied that the theoretical basis of the CSAMT and derivated the electromagnetic equation and fluctuation equation as well as spread equation in NEAR-FIELD. This shows a substantial and impressive understanding and knowledge in the CSAMT along with transient electromagnetic method, directing a commom expression of cagniard apparent resistivity based on Wave field equation. According to the border metadata calculation methods of electromagnetic field’ physics model and the restrained equation of electromagnetic numerical evaluation,it provides the conditions for electromagnetic equations resolving. IN the basis of theoretical researching,we study about the probabilistic questions met in working by using the CSAMT.It puts a high attention on Static effect researching and the happening reasons onear-field effect and its Processing Method,at the same time it discuss the questions like field source effections of the CSAMT and the false Extreme value effections.This article firstly and systematicly describes the influence of corner frequence, Magnetic probe deflection angle and Poor electrode to the Field Data quality, and it also discuss the impact underring a relationship between these three elements like electricity, voltage and power to electricity and magnetic field observations. It also do research in the Influential Law between corner frequent and apparent resistivity with corner frequent to phase. This passage have also extensively and completely given the corner frequent compute formula,which pointed that the corner frequent number would directly influence the resistivity and the accuracy of phase curve, at the same time draw a relatively satisfied conclusion in these the aspect of measurement error caused by different Magnetic probe deflection angle, concluding that the Placement of magnetic probe do an important influence on cagniard apparent resistivity. In the example of calculating with perpendicular bisector of emitter AB, its feature is:the higher the flare angle is, the larger the error of the cagniard apparent resistivity anomaly is. When the flare angle reaches at±30°, the error of the cagniard apparent resistivity anomaly increases linearly with increase of angle θ When φ=-25°and θ=+10°,the error of the cagniard apparent resistivity anomaly will get to230%. When φ=+25°and θ=-10°the error of the cagniard apparent resistivity anomaly will get to-50%. This paper makes an actual analysis of the error which committed by electrode potential gradient, and advances a technical indicators which can determine pros and cons electrodes with5%NaCl solution at room temperature. a. The range potential of two solid nonpolarized electrodes≦1mV; b.In24hours, inner range drift≦0.1mV; c.In10seconds, inner short periodic noise≦0.01mV; d.The frequency response range is0～10kHZ; e.The range of using temperature range is-20℃～40℃.This paper makes a reasonable configuration between the supplying of electric current and voltage, and gets a satisfactory conclusion.This passage shows a feasibility and effectiveness of CSAMT under the interact of formation temperature and formation broken through some representative successful examples in geothermal field exploration. CSAMT have those advantages like increase in Exploration,Depths anti-jamming capability and high work efficiency which really indicates a good method in Geothermal Field exploration further now. |
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