CSAMT Method For Shale Gas In Jinjiang Basin Research On Application Of Exploration

Jinjiang basin is located in the southern margin of Poyang Lake basin.Type of basin,tectonic location of the region,basin cover and Analysis on the occurrence environment of regional tight reservoir.The Permian Leping formation in the basin is characterized by large thickness,high abundance of organic matter and better preservation.In general,there are some basic conditions for the occurrence of tight reservoirs.Currently,the oil and gas resources in the basin are mostly in the stage of regional evaluation,Needs to investigate the structural features of the north slope of Jinjiang basin and the distribution of fault structures in the study area.Combined with geological and well logging data,the distribution of anomalies is analyzed,which provides a favorable location for the geological survey well.CSAMT has the exploration depth is moderate(Depth range of human mining activities),strong anti-interference ability,good vertical and horizontal resolution,high work efficiency,and has the advantages of double sounding and profiling,it is an effective method for geological mapping in geological exploration,to find and determine geological structure.In this paper,the selection principle of CSAMT sampling parameters is discussed in detail,the selection test(R)is performed.The technical measures to improve the quality of sampled data are studied.In order to improve the accuracy of inversion interpretation.In this paper,we focus on the study of the editing and smoothing of the raw data,the near field source effect,the static effect and the data inversion algorithm.Raw data editing smoothing denoising,data smoothing denoising using the reference phaseRaw data editing smoothing denoising,data smoothing denoising using the reference phase correction method.The elimination of the flying points is based on the comparison of the adjacent points and the one-dimensional inversion.The near field source and static correction method are discussed,through the qualitative analysis of the CSAMT electromagnetic sounding curves,the apparent resistivity frequency section and the phase frequency section.Based on the preliminary stratification of the profile,the one-dimensional inversion of Bostick is carried out,to have a general understanding of the characteristics of the interior structure and geological structure,the inversion results are used as the initial model of 2D inversion.Combined with outcrop lithology test,CSAMT sounding data,2D nonlinear gradient conjugate gradient method is used.The results of CSAMT interpretation correspond well with the known geological results.Avoid multiple interpretations,making the explanation more profound and credible.Through the above research work,the electrical structure and spatial distribution characteristics of the study area have been identified.The identification and division of the deep strata in the study area,the burial depth and thickness of the Leping formation of Permian are determined.In order to predict the shale gas and tight oil and gas resources in the study area,and to evaluate the overall resource potential of the basin,it provides a powerful geophysical basis.