利用环境敏感粒度组分分析滩坝砂体水动力学机制的初步探讨——以东营凹陷西部沙四上滩坝砂体沉积为例  

Preliminary Study on the Hydrodynamic Mechanism of Beach-Bar Sandbodies with Environmentally Sensitive Grain Size Components:A case study from beach-bar sandbody sediments of the upper part of the fourth Member of the Shahejie Formation in the Western Dong

作　　者：操应长[1] 王健[1] 刘惠民[2] 

机构地区：[1]中国石油大学(华东)地球资源与信息学院,山东东营257061 [2]中国石化胜利油田分公司地质科学研究院,山东东营257000

出　　处：《沉积学报》2010年第2期274-284,共11页Acta Sedimentologica Sinica

基　　金：国家油气重大专项(2008ZX05051-02);国家自然科学基金项目(批准号L40972080);教育部新世纪优秀人才支持计划(NCET-06-0604)资助

摘　　要：东营凹陷西部古近系沙河街组沙四上亚段沉积时期广泛发育了滨浅湖滩坝砂体沉积。在钻井岩心观察描述及其相关测试分析的基础上,利用粒级—标准偏差方法对滩坝砂体的环境敏感粒度进行计算,结合粒度概率图分析和古地貌、古水流研究,在研究区内确定出了四种环境敏感粒度组分,分别代表悬浮搬运、沿岸流、波浪和风暴浪。其中,波浪和沿岸流是控制滩坝砂体形成和发育的主要水动力类型。通过对波浪和沿岸流的环境敏感粒度组分占整个粒度总体的百分比的计算表明,波浪对滩坝砂体的形成和发育的影响程度由凹陷边部向内部逐渐减弱;而沿岸流对滩坝砂体形成和发育的影响程度在凹陷外部较小,而主要表现在滨浅湖区的内侧。Shore-shallow lacustrine beach-bar sandbodies widely developed during the period of the upper submember of the fourth Member of the Shahejie Formation of Paleogene in the Western Dongying Depression.The environmentally sensitive grain size components of beach-bar sandbodies have been studied using the method of grain size-standard deviation according to the description of cores and other correlated analyses and tests.Combined with the analysis of grain size probability curves and the research of palaeotopography and palaeocurrent,there four kinds of environmentally sensitive grain size components were determined in the study area,which respectively represents suspension transportation,coastal current,wave and storm wave or gravity flow.Wave and coastal current are the main hydrodynamics of the four kinds of hydrodynamics which control the formation and development of beach-bar sandbodies.Wave is the most important hydrodynamics that control the formation and development of beach-bar sandbodies according to the calculation of the percentage of environmentally sensitive grain size components of wave and coastal current in the grain population.The energy of wave and its control degree to the formation and development of beach-bar sandbodies decreases from the outer to the inner part of shore-shallow lacustrine.The effects of coastal current mainly exist in the inner part of shore-shallow lacustrine.

关 键 词：滩坝 粒级—标准偏差 环境敏感粒度组分 水动力 东营凹陷 

分 类 号：P512.2[天文地球—地质学]