Research On Inversion Technique Of Distribution Characteristics Of Gravity And Magnetic Tensor Field Sources

The gravity and magnetic tensor data has the advantages of high precision,multiply parameters,and higher resolution to the geological mass.In this paper,aiming to obtain the accurate spatial distribution of the potential source by using the multiparameter gravity tensor data,based on the feature of the gravity and magnetic tensor data,the forward and inversion studies are carried out,focusing on key issues such as multi-source data fragmentation,data information constraints.The paper mainly carries out the following studies:(1)the "singularity" problem in the formula of the gravity tensor anomaly of the prism,which provides theoretical support for the inversion;(2)the formulation of using the Euler deconvolution formula of different heights and the multi-height joint inverse,this provides a new idea for the acquisition of aeromagnetic gravity and its tensor data;(3)The wavelet analysis can effectively extract the characteristics of different scale information,so I combine the wavelet transform and Euler deconvolution to achieve high resolution potential source position;(4)Joint inversion technique of gravity and magnetic tensor data based on correlation analysis constraints can reduce the complexity and multiplicity of gravity and magnetic data interpretation;(5)Conjugation gradient physical property of Euler deconvolution inversion results improves the efficiency of inversion while ensuring the accuracy of the inversion results.The paper starts from the forward problem.Aiming at the problem of analytic "singularity" in the forward formula,the author analyzes the reason of the existence of "singularity" in the gravity gradient from the formula of the tensor anomaly.I try to avoid the "singularity" problem in two ways.Firstly,consider using a special splitting method in the observation surface to avoid the coincidence of the projection point of the prism corner on the observation surface and the mesh;secondly,to derive a new forward formula without analytic "singularity" gravity tensor anomaly.Thereby obtaining more accurate forward anomalies and providing theoretical support for subsequent inversion.In the process of Euler inversion,it is difficult for the operator who lacks the relative background to determine the parameters which is divergence.The smallwindow and multi-data Euler deconvolution inversion method is proposed to solve the problem that the inversion result which is not focused.In order to solve the problem of smoothing solutions when using large windows and inaccuracies of solutions caused by mutual interference of different potential sources,using small windows and statistical data to carry out detailed research on potential sources,and exploring the impact of small window multi-data on Euler deconvolution method,theoretical analysis and calculation of joint inversion of multiple different height data.Joint inversion of different height data can provide new ideas for the collection of aviation gravity and its tensor data.Since the quality of the data collected in airborn survey is affected by the altitude of the aircraft,I consider choosing a suitable altitude and measuring two or more altitudes to further improve the speed of the airborn measurement while ensuring flight safety.In addition,for the Euler inversion results are susceptible to noise interference,wavelet transform is used to reduce noise,and wavelet can be decomposed into details in different directions and depths to extract the characteristics of effective information,combine the wavelet transform and Euler deconvolution inversion to achieve high-precision inversion of the potential source location.According to the equivalence of the potential field theory,there are problems of the complexity and instability of gravity and magnetic data in processing and explaination,the gravity-magnetic correlation analysis is introduced as the constraint to realize the Euler the joint gravity-magnetic deconvolution.According to the potential source effect of the target,add the correlation coefficient as the filter condition for the calculation.Taking M area in China as an example,the correlation analysis method and application of aeromagnetic data and ground gravity data are discussed.By calculating the gravity and magnetic correlation coefficients,combined with the geological conditions of the study area,the nature and geological characteristics of the anomaly source are deduction,and reduce the geological inversion multi-solution.For the multiplicity of physical inversion and the problem of multiplication of computational complexity after adding constraints,a conjugate gradient physical property inversion method based on Euler deconvolution inversion results is proposed.Different tensor anomalies can reflect the different boundary information of the geological body.By inverting and comparing the tensors in different directions,the geological body information contained in the single-volume data is analyzed.The tensor data in a single horizontal or vertical direction is relatively divergent relative to the full tensor data.Considering the inversion of different tensor components,you can get a more comprehensive understanding of the general situation of the geological mass.the joint inversion is carried out using the advantages of Euler deconvolution method and conjugate gradient physical property inversion method,and the Euler deconvolution inversion result is used as the initial constraint condition of physical inversion,and the calculation model of physical inversion is established.Effectively improve the efficiency of the operation.The method is applied to the measured gravity tensor data of the Wendun salt dome,and the Euler deconvolution result of the full tensor data gives the depth,spread range and thickness information of the rock cover,and the Euler deconvolution constraint The conjugate gradient physical property inversion results not only give the thickness of the rock cover,but also the spatial distribution of the whole rock mass,which can improve the calculation accuracy of oil storage provides important technical support of oil and gas for the further exploration.