Application of gravity imaging to geothermal exploration

摘要

In the exploration of geothermal water in China,gravity method comes to be a major method because of its sensitivity to linear structure,especially to the fault,and the high efficiency to planimetric exploration.In order to improve the effect of gravity method exploration,imaging technology is often used for extracting the implicative information the survey data.Two successful case histories of applied gravity imaging technology to geothermal exploration are presented in this paper.Different kind of imaging technology,planar imaging and pseudo-depth imaging based on wavelet analysis,were used to respective case.In the case of planar imaging,the gravity anomaly was converted with a suited grid density to a value of the grayscale or brightness.Then we can display the gravity anomalies using the converted result.This kind of imaging technology was used to the first case history for mapping the fault and the boundary of the high-density rock.The pseudo-depth imaging was used to another case history for mapping the variation with its buried depth of a fault.1-d continuous wavelet analysis was used for generating the pseudo-depth value of the gravity profile.This is only an experiment although the result was concordant to which of the CSAMT in the same site.