用相域迁移法绘制河流基准面变化曲线--以苏里格气田为例

基准面的升降造成有效可容空间内相系列向陆和向盆迁移.根据这一原理可绘制基准面变化曲线.以苏里格气田二叠系河流相地层为例来阐述这种方法.将目的层段所有准层序按照所代表的不同沉积相和能量级别划分为5种类型.它们沿水流方向形成一个相系列.将研究区划分为上游、中游和下游3个区,分区统计出每个准层序（层）内出现频率最高的准层序类型,以这种类型作为该区、该准层序（层）的准层序代表类型,然后将各区准层序代表类型连接起来,从而分区绘制了基准面变化曲线.最后通过统计全区1 m以上砂体的平均厚度在各准层序（层）中的变化趋势来定量验证上述基准面变化曲线.

Making Curves of Base Level Changes by Facies Series Shift Method--An example of Sulige gas field

The ascending-descending base levels cause that facies series in effectively allowed spaces shifts landward and basinward. The curves of base level changes can be made based on this principle. This method is elaborated by examples of the fluvial strata of Permian in Sulige gas field. The quasi-sequences in the target zones are divided into five types in terms of individual sedimentary facies and ener- gy, and they form a facies series along the water flow. Hence, the studied area could be divided into three sections: upper reach, middle reach and lower reach. Stat and choose the best frequent quasi-sequence in each one, then link all the quasi-sequences in each section. and make curves of the base level changes. These curves are testified quantitatively by the varied tread of average thickness in sand body of over 1m.