沾化凹陷四扣洼陷及周缘地区在古近系沙四上亚段沉积时期发育了一套礁灰岩。在薄片观察和岩心分析测试的基础上,结合地层对比和储层物性分析,对礁灰岩储层特征及有效圈闭形成的控制因素进行研究,划分灰岩圈闭成因类型,探讨其在油气成藏中的控制作用。研究表明:湖相礁灰岩具有发育层位相对稳定、礁体规模不一、礁滩混杂、储层非均质性强等特点;礁灰岩圈闭的发育主要受沉积相带、成岩作用和构造运动的影响,可形成控制礁灰岩油气成藏的4类圈闭;礁灰岩圈闭类型在油气成藏过程中起双重控制作用,一方面控制了礁灰岩圈闭的有效性,另一方面控制了油气成藏的时间、输导体系类型和运移充注方式。
During the period of the upper part of the Es4 formation of Paleogene,Sikou sag and peripheral area of Zhanhua depression developed reef limestone.Based on the slices observation and cores analysis and test,combined with the analysis of reservoir quality and strata correlation,the reef limestone reservoir characteristics and controlling factor of available traps formation were studied.And the genetic types of reef limestone traps were classified and its control over reservoir formation was discussed.The results show that the lake reefs only developed in peculiar formation,have different sizes,and reef and reef flat are chaotic,superimposed and cross connected.The reef reservoir quality is highly heterogeneous.The formation of available reservoir is affected by sedimentary facies,diagenesis and tectonic movement.Four genetic types of reef limestone traps were classified,which has double influences on the oil and gas pool formation.The types of reef limestone traps are related to tarp s validity,and play an essential role on reservoir formation time,migration pathway and the types of injection.