惠民凹陷沙一段湖相碳酸盐岩层序地层分析

Analysis on sequence stratigraphy or lacustrine carbonate in the first member of Shahejie Formation in Huimin Sag

针对惠民凹陷西部湖相碳酸盐岩储层薄、横向变化快、旋回性发育的特点,利用沉积学和层序地层学理论和方法研究了该区沙一段湖相碳酸盐岩沉积旋回的发育规律。研究结果表明,湖相碳酸盐岩在滨浅湖、半深湖和火山锥附近均有发育,且不同沉积环境的碳酸盐岩准层序具有不同的分布规律、识别标志及形成机理;研究区碳酸盐岩的发育受海侵作用、气候变化和火山活动的影响,其中气候的周期性波动和火山的多期喷发控制着湖相碳酸盐岩准层序的发育。

The carbonate reservoir of lacustrine facies in the western Huimin Sag has the features of thin thickness, great lateral variation and developed cycles. The sedimentology and the sequence stratigraphy principles were used to study the development rules of lacustrine carbonate sedimentary cycles in the first member of Shahejie Formation. The result showed that lacustrine carbonate developed in the littoral-shallow lake, hemi-deep lake and near volcanic cone. The carbonate parasequence in the different sedimentary environment has the different distribution rules, identification symbol and forming mechanism. The development of lacustrine carbonate was influenced by marine transgression, climate change and volcanic activity. The periodicity fluctuation of climate and volcanic eruption of multistage controlled the development of lacustrine carbonate parasequence.