渤海湾盆地济阳坳陷沙四段和孔店组地层剥蚀厚度恢复  

The Estimation of the Erosion Thickness of Es_4 and Ek in Jiyang Depression, Bohai Bay Basin

作　　者：韩用兵[1] 王良书[1] 刘绍文[1] 

机构地区：[1]南京大学地球科学系,南京210093

出　　处：《高校地质学报》2004年第3期440-450,共11页Geological Journal of China Universities

基　　金：国家重点基础研究发展项目 (G19990 4 330 2 );胜利石油管理局地质科学研究院"十五"重点攻关项目资助

摘　　要：采用改进的声波时差法原理 ,将优化孔隙度法的算法引入到声波时差法 ,模拟计算地层剥蚀厚度。对于被剥蚀地层沉积规律被改造的区域 ,则结合地震剖面的地层对比法来恢复地层剥蚀厚度。通过多方位运用地层对比法 ,然后再将所得计算结果加权平均得到最终的地层剥蚀厚度 ,使计算误差降低。计算结果表明 ,沙四段和孔店组地层剥蚀现象普遍 ,但总的剥蚀量较小 ,且剥蚀厚度相对较大的区域集中在凹陷的边缘。沙四段地层剥蚀量大多集中在 5 0～ 30 0m ,平均剥蚀量为 15 0m左右 ,最大剥蚀区在鲁东隆起区西侧的凹陷边缘 ,最大剥蚀量近 10 0 0m ,但范围较小 ;孔店组的剥蚀量相对于沙四段要大 ,一般在 15 0～ 4 0 0m ,平均剥蚀量在 2 5 0m左右 ,最大剥蚀区在惠民凹陷东北缘 ,最大剥蚀量在 80Recovering the erosion thickness of the formation is one of the foundations for basin quantitative analysis. Here we estimated the erosion thickness of the Es4 ( the fourth member of the Shahejie Formation) and Ek ( Kongdian Formation )strata in the Jiyang Depression by means of computer modeling, based on the improved sonic time difference principles, and combined with the optimizing porosity algorithm. The stratigraphic contrast method on seismic profiles is combined to estimate the erosion thickness for the places where the sedimentation regularities of removed formation are destroyed heavily. This traditional method is also improved in this paper. The final erosion thickness of formation is obtained by the weighted average of variously calculated results abtained by using multi-perspective stratigraphic contrast method, so that the calculation errors could be significantly reduced. Our results show that the erosion exists pervasively in the Es_4 and Ek strata of the oilfield with a relatively smaller intensity, and the relatively larger erosion is found in the fringe of the sag. The erosion amount of the Es_4 ranges of 50～300 meter, with the average of 150 meter; The largest one exists in the edge of western sag of the Luxi Uplift reaching a value of approximately 1000 meter, but localized in a relatively small area. The erosion amount of Ek is relatively larger than that of the Es_4, usually varying from 150 to 400 meter, with the average of 250 meter. The largest one is found in the northeast rim of the Huiming sag, with the value of 800 meter.

关 键 词：济阳坳陷 沙四段 孔店组 剥蚀厚度 声波时差 地层对比法 

分 类 号：P512.2[天文地球—地质学]