综合岩心资料、薄片资料、压汞资料、物性资料等多种资料,对饶阳凹陷留西地区东北部沙三段低渗储层进行了研究.研究表明,研究区沙三段砂岩储层岩石类型以岩屑质长石细砂岩、长石细砂岩为主,岩石成分成熟度和结构成熟度中等,反映近物源的特征.通过薄片资料、分析化验资料,认为研究区沙三段储层主要经历了压实、胶结、交代及溶解等成岩作用,孔隙组合类型以残余原生粒间孔、次生粒间孔和粒内溶孔为主.根据物性资料,显示研究区储层多以中-低孔、低渗为特征.研究区储层平均埋藏3175m,受沉积作用、成岩作用的双重控制,孔隙发育较差,储层致密,是造成沙三段砂岩低孔、低渗的主要原因.进一步研究表明沉积作用是储层低渗主控因素,影响储层原始物性;成岩作用中压实作用起主导作用,胶结作用进一步破坏物性,溶蚀作用改善储层物性,特别体现在沙三底部因溶蚀作用形成大量次生孔隙,使得物性优于其他小层砂体.%By means of the core data,thin section data,mercury penetration,physical property data and other data,we study the low permeability resorvoirs of Es3 in the northeastern part of Liuxi Region in Raoyang Depression.The research shows that the lithic arkose fine sandstone and feldspar fine sandstone are the main rock types of reservoir in the studied area.The composition maturity and structure maturity are the medium degree which show the feature of near resource.Through analysis of the thin section data and analytical laboratory data,we find the reservoirs of Es3 are mainly experienced compaction,cementation,metasomatism and dissolution in the burial diagenetic evolution.Pore combination types are maily included the residual primary intergranular pore,secondary intergranular pore and intergranular dissolved pore.The reservoirs are mainly medium-low porosity and low permeability reservoir according to physical property data.The average buried of reservoir is 3175 m.Controlled by sedimentation and diagenesis,its pores are poor and the reservoirs are conpact,which cause the low porosity and the low permeability.The further research shows that sedimentation is the main controlling factor of low permeability reservoir,infecting the original physical properties of the reservoir.The compaction plays a leading role and the cementation further damages the physical properties.The dissolution improves the reservoir physical properties,especially a large number of secondary pores are generated in the bottom of Es3 due to dissolution,making its physical properties are superior than the other sand body of Es3.
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