Study On Inversion Of Full Field Potential In Shallow Parallel Electrical Method

Parallel electrical exploration technology is a geophysical exploration method based on the electrical difference between geological anomaly body and its surrounding stable medium.The parallel electrical method is a method of collecting the whole field potential of the measuring line by one-time power supply,but at present,a large number of data are not used in the data processing of the parallel electrical method.In this paper,the inversion of the total field potential value by parallel electrical method is studied by theoretical analysis,physical simulation and engineering application,the results are as follows:There are two data acquisition methods for parallel electrical method,ABM and AM.The ABM method is not suitable for full field potential inversion because of the large number of power supply times and the large amount of full field potential data;The AM method is suitable for full field potential inversion.The left potential value of AM data supply point is not stable,and the right data is usually used for processing.The two pole method is the full field potential inversion,but the two pole inversion has strict requirements on the N pole of field data acquisition.In practical application,the N pole does not meet the requirements of the two pole inversion,so this method can not be used;Wenner triode data has good application effect and is a common method in high density resistivity method;The full field potential value is used in the adjacent source triode,which effectively overcomes the disadvantage of the low signal-to-noise ratio of the potential data far away from the power supply pole,improves the signal-to-noise ratio of the data,and the amount of data is moderate,so it is suitable for the full field potential inversion;The full field three pole method is a multi electrode distance three pole processing method,which extracts the potential data of any two poles on the right side of the power supply point,and the amount of data is much larger than that of Wenner three poles.Physical simulation experiments show that Wenner triode method,adjacent source triode method and full field triode method can better reflect the position of the target in the survey line section.The results of Wenner triode method and full field triode method are generally equivalent,and the electric property change reflected by full field triode method is the most precise.Three dimensional electrical inversion shows that the Wenner triode method,the adjacent source triode method and the full field triode method can better locate the target in three-dimensional space.The inversion results of the adjacent source triode method have higher resolution for shallow layered strata,and the Wenner triode method and the full field triode method can accurately reflect the location of the target.The engineering application shows that the two-dimensional inversion adopts the whole field apparent resistivity and the three-dimensional inversion adopts the Wenner apparent resistivity,which can more objectively reflect the distribution space of the relatively low resistance area,better explain the relatively rich water area and guide the water disaster prevention and control work of the working face.Figure[35]Table[7]Reference[89]...