史南地区沙三段浊积砂体成因模式探讨

Discussion on the genesis model for turbidites of Es3 in Shinan area

在史南地区区域性地震层序划分和沉积体系研究的基础上,应用高分辨率层序地层学研究方法,通过分析基准面的升降变化对砂体的成因模式进行了初步探讨,将浊积砂体划分为滑塌浊积岩、坡移浊积扇和湖底扇三种圈闭类型,每种类型圈闭的形成和分布都与基准面的升降变化密切相关。湖底扇和坡移浊积扇圈闭形成于基准面上升期,是该区主要的储油圈闭;滑塌浊积岩圈闭主要形成于基准面下降期,规模较小,储集物性较差。

Based on the regional divisions of seismic sequence and the study of sedimentary system in Shinan area, high resolution sequence stratigraphy is applied to analyzing the sandstone genesis models by the heave variation of base level. The turbidite is divided into three types of traps; fluxoturbidite, talus turbidite fan and sub-lacustrine fan. The form and distribution of every type of turbidites are closely related to the heave variation of base level. The sublacustrine fan and talus turbidite fan, formed during the ascending period of base level, are the leading oil -accumulation trap of the area. The fluxoturbidite, formed during the descending period of base level, is of small scale relatively and poor petro-physical properties.