扇三角洲露头层序演化特征及其对砂岩储集层的控制作用

Sequence evolution of fan-delta outcrops and its controlling on the sandstone reservoirs

在对河北省滦平扇三角洲露头储集层砂体类型和分布规律的详细解剖和层序地层学研究中发现,基准面的旋回演化对砂体类型分布和砂体规模的变化有较明显的控制作用,即使对于同一种沉积微相类型的砂体,其厚度和宽厚比也会随着基准面的旋回发生有规律的变化,远岸水道砂体在高可容纳空间时期宽厚比变大,在低可容纳空间时期宽厚比变小,厚度增大。在地质建模中引入层序地层学规律和认识作为限制条件,可以更加有效地控制对砂体类型和砂体规模的随机实现,使模拟结果更加符合地质规律和客观实际情况。

The detailed studies of sand body type and distribution of the Luanping fan-delta outcrops and sequence stratification research suggest that the distribution of sand body types and their scales are controlled by the base level cycle. Even if the sandstone bodies belong to the same type, their thickness and width/thickness ratio will be changed regularly with the rising and falling of the base level. The width/thickness ratio of the off-shore channel sandstone body is relative large in a high accommodation, and will decrease with the decline of accommodation, but the thickness will be increased. Bring in stratigraphic laws and knowledge as restrictions, the stochastic distribution of sand body types and scales can be controlled more effectively and the simulation will be more coupled with real facts.