鄂尔多斯盆地蟠龙油田长6储层特征及影响因素

通过研究区内大量铸体薄片及物性资料分析,对鄂尔多斯盆地蟠龙探区长6油层组储层的孔隙类型、岩石学特征、孔渗特征及孔隙结构进行深入研究,分析储层储集性能的主要影响因素.结果表明,蟠龙探区长6储层整体具有成分成熟度偏低,结构成熟度较高的岩石学特点.长6储层岩性段主要为细粒和细-中粒长石砂岩、岩屑长石砂岩,小孔是主要的油气储集空间,细喉则是长6的基本渗流通道,为典型低孔、特低渗储集层.胶结类型以孔隙-薄膜式胶结为主,接触关系以线状为主,凹凸状接触也很普遍.长6储集层的物性主控因素主要包括:沉积微相、砂岩物质成分、压实和压溶作用、溶蚀作用及后期裂缝.其中储集砂体所处的沉积环境是影响该区储层物性最主要的因素.

Characteristics and Influential Factors of Chang 6 Reservoir of Panlong Oilfield in Ordos Basin

Through analyzing large amount of casting thin sections and geological data of the study area,pore types,petrological characteristics,porosity,permeability characteristics and pore structures of Chang 6 reservoir of Panlong oilfield in Ordos basin were studied,influential factors for reservoir properties were analyzed.The results show that petrological characteristics of Chang 6 reservoir in Panlong oilfield is low compositional maturity and high structural maturity.The lithology of Chang 6 reservoir is fine-grained and fine-medium grained feldspar sandstone,lithic feldspathic sandstone.Main reservoir spaces are pores.The small throat is main seepage channels of Chang 6 oil flowing.It’s typical low porosity and low permeability reservoir.Cementation type is porosity-film type,contact relationship is linear,uneven contact is also very common.Main influential factors for physical properties of Chang-6 reservoir include microfacies,sandstone material composition,compaction and pressure dissolution,dissolution and post-crack,in which depositional environment of the reservoir sands is the most important influential factor for reservoir properties in the area.