厚层切叠砂体自然层描述方法:以北一区断东葡一组1-4小层为例

将多期切叠河道砂体归类合并,建立一个“垂向连续,横向联通的表外砂岩空间体”(其中砂岩间夹层厚度≤0.4 m)的自然层概念来控制多期河道复合切叠厚砂体。以北一匹断东萄一组1-4小层为例,利用自然层间砂体厚度、切叠程度、测井曲线形态、相叠加类型及砂体叠加期次将自然层分为5类;再依据砂体间切叠位置、切叠程度和切叠形态的差异建立自然层剖面表征方法;依据砂体叠加期次,建立自然层在平面上表征模式。

Natural layer description method of thick overlapping sand bodies:an example from 1st to 4th layers of Putaohua 1st Formation in eastern fault block of Beiyi district

After categorizing and merging multi-phase overlapping channel sand bodies,the authors establish a natural layer concept to describe a“verticaly continuous,horizontally connected sandstone space body”(sandwich layer thickness<0.4 m),consisting of multi-phase complex overlapping channel sand bodies.The natural layers are divided into 5 types according to the thickness of the sand bodies,the degree of overlapping,the shape of logging curve,the type of sedimentary facies and the superposition period of the sand bodies.Furthermore,the characterization of the natural layer profile is established based on the differences in sand body overlapping positions,degree of overlapping and overlapping pattern,and a characterization model of the natural layer distribution on the plane view is also established according to the stacking period of the sand bodies.