延安三角洲储集层特征

Reservoir Characteristics of Yan'an Delta

采用宏、微观结合研究方法,对储集层砂体发育、岩石学特征、孔隙结构、物性及其影响因素进行了分析,根据大量岩心薄片、铸体、物性等分析资料,结合近年来延安三角洲油气勘探进展情况,经统计分析提出了研究区储集层以长4+5及长61、长62油组相对较好,总体以三角洲前缘分流河道微相发育区最好的观点。储集空间以粒间溶蚀孔、粒间余孔为主,物性虽普遍偏差、属低孔低渗储集层,受压实作用影响明显,但与国内同类低孔低渗油田相比仍具有较大开发潜力,值得重视。

This paper highlights the reservoir sand body,petrology,pore structure,petrophysical properties and their effects in Yan'an delta by way of macroscopic and microscopic study,including thin-section and cast thin-section analysis data,etc.Inte-grating with petroleum exploratory progress of the delta,this paper proposes statistically that Chang-4+5,Chang-61and Chang-62oil layers in target area are better than other layers.In general,the microfacies-developed zone of distributary channel in the delta front is the most favorable for hydrocarbon prospecting.In spite of belonging to low porosity and low permeability reservoir with compaction and dominated by intergranular dissolved pores and intergranular residual porosity,Yan'an delta still has greater potentials for petroleum development compared with the similar domestic fields.