鄂尔多斯盆地姚店油田长6油层微观孔隙结构研究

The microscopic pore structure studying on the chang 6 reservoir in yaodian oilfield,Ordos Basin

利用铸体薄片、扫描电镜、高压压汞等实验技术,对鄂尔多斯盆地姚店油田长6油层组的微观孔隙进行了研究。研究结果表明,研究区储层岩石类型主要为长石砂岩,胶结物主要为方解石,黏土矿物以绿泥石为主,伊利石及伊/蒙间层(I/S)次之。孔隙类型以溶孔为主,粒间孔次之,溶孔主要以粒间溶孔和粒内溶孔为主。根据毛管压力曲线形态和参数特征,研究区孔隙结构可划分为四类,从Ⅰ类到Ⅳ类其渗流能力逐渐变差。孔隙结构特征参数分析表明,储层非均质性较强,大孔道对渗透率的贡献较大,中、小孔隙给储层提供了更大的储集空间。

The feature of microscopic pore structure in chang 6 Reservoir of Yaodian oilfield in the Ordos Basin is researched based on the experimental technique of casting thin sections,scanning electron microscope and high-pressure mercury injection. The results show that,the lithology in this area is mostly arkose sandstone,Cement is mainly calcite,the chlorite is the main clay mineral component,the illite and illite / smectite mixed layer are the secondary clay minerals. Dissolved pores which are mainly intergranular dissolved pore and intragranular dissolved pore are the main pore types,Intergranular pore are the secondary pore types. The types of pore structure in study area can be divided into four types based on the capillary pressure curve shape and parameter characteristics,and the seepage ability gradually worse from class I to class IV. The characteristic parameters of pore structure analysis shows that,reservoir heterogeneity is serious,large pores have a big contribution to permeability and the small pores of reservoir provide greater storage space.