重力数据指数变换斜导数对盆地盖层构造提取研究OA

The study of the strudural of the basin caprock is the key to get breakthroughs in oil,gas,and sandstone-type uranium deposit exploration.Conventional gravity boundary enhancement methods are not satisfactory ideal enough in distinguishing the boundary of superposed anomalies of the basin caprock.Therefore,this paper proposed an edge-enhancement method of the tilt angle based on exponential transformation(E-TDR).By using the exponential growth and decay characteristics of the exponential function of the natural constant,the data range of the tilt angle is mapped from(-π/2,π/2)to the exponential scale while keeping the position of the zero-value point unchanged to highlight the boundary position.The combined model test proved that this method not only improved the resolution of field-source boundary identification but also enhanced the ability to identify adjacent or superposed geological bodies.When this method was applied to the gravity data processing in the Mangya area of the western Qaidam basin,the results show that this method effectively highlights the weak information of the fault-fold structures in the caprock of the study area,obtaining clearer edge detail information.Which help the newly inferred of the Hongliuquan and Alar buried fold tectonic belts,and the positions and scopes of the fault-fold tectonic belts such as Shizigou,Ganchaigou,Youshashan,Youquanzi and Nanyishan are re-determined.This achievement provides an important basis for the study of the uranium and hydrocarbon reservoir forming patter in the caprock(Neogene)of this area and the prospecting in the periphery(Qiqüanquan oilfield and uranium deposit are controlled by the Qiqianquan fold,while Yuejin oilfield and uranium deposit are controlled by the Alar concealed anticline structure).Therefore,this proposed method is of great significance for the identification of the structure edges in the basin caprock with gravity data and provides new technical support for the processing,interpretation of gravity data in the basin,and uranium prospecting.