东濮凹陷浅层砂岩的微观输导性能及其油气地质意义

摘要

There has no the ability of generating oil and gas in the shallower strata of Dongpu sag.Developed as one of the most important transporting body,the sandstone connects deeper hydrocarbon source rocks and shallower trap,so sandstone transporting capability directly determines if or not the hydrocarbon accumulation can happen in the shallower strata.The evaluation of sandstone transporting capability is one of weak links in the study of transporting body;the micro-transporting characteristics determine quality of sandstone transporting capability.Since there has defects in microscopic property measurement techniques of conventional sandstone,this article by means of the measuring software on pore diameter named Scandium in scanning electron microscope for the first time,the sizes of pore and throat of shallower strata in Dongpu sag are distinctively measured systematically in microscopic scaling.Then the longitudinal distributing characteristics are summarized.The transporting capability of the sandstone and its change are analyzed.All of these offer a new method in the study of pore structure and sandstone transporting capability.It shows those throat width and pore-to-throat ratios are the main factors influencing the transporting capability of shallower strata.The sequence of sandstone transporting capability more and more better are the first segment of Shahejie Fm.（Es1）,to Dongying Fm.（Ed） and Guantao Fm.（Ng）.However,the transporting capability in Minghuazhen Fm.（Nm） upon Guantao Fm.（Ng） is worse again;Hereby,if the others conditions of migration and accumulation are satisfied,hydrocarbon may migrate to the Guantao Formation and accumulate here.%砂体作为东濮凹陷浅层发育的主要输导体之一,其微观输导特征,决定了输导性能的优劣。利用场发射环境扫描电镜下的Scandium孔径测量软件,从微观尺度,较为系统地测量了东濮凹陷浅层砂体的孔隙、喉道大小,并总结了它们在纵向上的分布特征,分析了不同层段砂岩的输导性能及其纵向变化,这为研究孔隙结构和砂岩输导性能提供了一种新的方法。研究认为,喉道宽度和孔喉比是影响东濮凹陷浅层砂体输导性的主要因素,在层位上从深到浅,由沙一段→东营组→馆陶组输导性能越来越好,再向上至明化镇组时又变差。据此分析,如果满足油气运移、成藏的其