跨孔电阻率法装置灵敏度分析及分辨率讨论

Analysis of sensitivity of arrays and resolution discussion of cross-hole resistivity method

由于跨孔电阻率法的测量区域在两孔之间,对其测量装置的排列方式、灵敏度及分辨率等的研究,与常规地面电阻率法有较大的不同;影响其分辨率的因素也比常规地面电阻率法多.跨孔电阻率法的装置排列方式不同,其灵敏度范围和分辨率不同.针对跨孔电阻率法的二极、三极、四极装置,通过Fréchet导数分析了各装置的灵敏度,并确定了适用于跨孔探测的装置排列方式.在此基础上,本文建立不同的异常体模型,以四极装置为例进行了数值模拟,并综合灵敏度剖面图,讨论了相关装置的横向、纵向分辨率和影响因素.研究表明:灵敏度与分辨率的关联,灵敏度等值线剖面图的疏密、形态、正负值范围等对分辨率有着直接的影响.在跨孔电阻率法探测中,对各种复杂异常体在反演图中所呈现的不同形态进行区别分析归类,具有实际意义,这为提高现场勘探效率,增强采集数据的分析、解释的准确性,提供了理论依据和实验指导.

As the measurement area of cross-hole resistivity method is between the two holes,the measurement arrays,the sensitivity and the resolution are quite different from the common ground resistivity method,and the factors that affect their resolution are also more than it. Sensitivity range and resolution varies according to the arrays of cross-hole resistivity method. The sensitivity of each arrays is analyzed by the Fréchet derivative for the pole-pole array,dipolepole array and dipole-dipole array of the cross-hole resistivity method, and the array suitable for cross-hole detection is determined. On this basis,established different models,and the numerical simulation of the dipole-dipole array was carried out as an exemplification. Combined with the sensitivity profile, the horizontal and vertical resolution and influencing factors of the array were discussed. It is confirmed that the sensitivity is related to the resolution,Sensitivity contours of the profile of the density,shape,positive and negative range of the resolution has a direct impact. In the study of the cross-hole resistivity method,the different shapes of the different abnormalities in the inversion can be classified and analyzed. This provides the theoretical and experimental basis and guidance for improving the efficiency of on-site exploration,enhancing the analysis and interpretation of the data.