东营凹陷典型剖面重磁电震综合解释方法研究

Gravity-magnetic-electric-seismic integrated interpretation method for typical profile of Dongying Sag

潜山内幕、砂砾岩和深层地质体是东营凹陷地震勘探相对困难的目标。为此,选择总长度约100 km的SL616测线进行了重磁电震综合解释方法的研究,该测线依次经过广饶凸起、东营凹陷和陈家庄凸起3个二级构造单元。阐述了航磁资料的三维欧拉反褶积、电法资料的快速松弛反演(RRI)和重力资料的约束正反演等处理方法。地震勘探中存在屏蔽效应的潜山、砂砾岩体等隐蔽地质目标在重磁电资料上有明显的异常特征。通过重磁电震资料的综合对比分析,重新认识了潜山内幕、砂砾岩体、边界断裂和深部地层,发现了新的地质体。认为陈家庄凸起并非是单一的太古界地层,其内部存在断裂和低阻、低密度体;根据地震资料解释的东营凹陷古生界顶面最深点应向北偏移。

Buried hill,deep geological body and glutenite are the relatively difficult exploration targets in Dongying Sag.Aiming at this problem,line SL616 with a total length of about 100 km was utilized to discuss gravity-magnetic-electric-seismic integrated interpretation method;the line is located in the east of Jiyang Depression, crossing three secondary structure units,including Guangrao Salient,Dongying Sag and Chenjiazhuang Salient.The 3-D Euler deconvolution for aeromagnetic data,rapid relaxation inversion for electric data,constrained forward modeling and inversion methods for gravity data were introduced.Some subtle geologic targets,such as buried hill and glutenite,which have shielding effect in seismic exploration,also have obvious anomaly on gravity-magnetic-electric data.Through integrated analysis of gravity,magnetic,electric and seismic data,the inner buried hill,glutenite,boundary fault and deep formalions were re-identified,and new geologic bodies were found.The result shows that Chenjiazhuang Salient is not the unique Archaean strata,fault,low-resistivity and low-density bodies exist inside the salient.From the seismic data,the deepest Paleozoic strata in Dongying Sag should be shifted northward.