东营凹陷前古近系构造综合地球物理反演

以地质、重磁、地震、测井、岩石物性及分析测试资料为基础,建立了东营凹陷前古近系深层密度的空间变化模式并进行了地球物理反演。结果表明,东营凹陷前古近系沉积主要受北西向构造的控制,太古界构成东营凹陷的结晶基底,是一个北东转近东西向的北陡南缓的断陷,最深处位于现河、辛镇一带,可达12000m;下古生界奥陶系构造具有很强的继承性,其构造格局与太古界有很强的一致性;中生界宏观上继承了下古生界的构造形态,但填平补齐和局部改造比较明显,凹陷范围明显缩小。东营凹陷前古近系断裂构造总体格局为向北东撒开、向西南收敛的束状构造,且可以分为高青博兴断陷区、利津草桥断陷区、东营王家岗断陷区3个断块。东营凹陷边部的隆起地带发育有3条火成岩带。与钻遇井深度比较,中生界和下古生界深层构造的反演精度分别达到91.14%和88.17%。

Research of comprehensive geophysical inversion of pre-Tertiary tectonics in Dongying depression

Based on geological, gravity and magnetic, seismic, logging, physical properties of rocks and testing data, the spatial variation pattern of pre-Tertiary deep density in Dongying depression was established and geophysical inversion was carried out.Results of inversion show that pre-Tertiary deposition in Dongying depression is controlled with westnorth structures. Archaean group is the crystal basement of Dongying depression, which is a north steep and south gentle rift-subsidence basin striking from eastnorth to near westeast, and the deepest position is up to 12?000 m at the area of Xianhe and Xinzhen. The configuration of Ordovician of lower Palaeozoic system highly inherits that of Archaean group and both have a strong consistency. The configuration of Mesozoic inherits that of lower Palaeozoic system as a whole, but filling and local reconstruction are distinct, and the scope of Dongying depression has obviously decreased. The general frame of pre-Tertiary faults in Dongying depression is a fascicular structure scattering toward eastnorth and converging toward southwest. Dongying depression contains Gaoqing-Boxing, Lijin-Caoqiao and Dongying-Wangjiagang rift-subsidence. At uplift area surrounding Dongying depression developed three igneous rock belts. Compared with depths of penetration wells, the inversion accuracies for Mesozoic and lower Plaeozoic deep structure are up to 91.14% and 88.17% respectively.