鄂尔多斯盆地华庆地区长9储层微观孔隙结构特征

Micro pore structure characteristics of Chang 9 reservoir in Huaqing area,Ordos Basin

为了查明鄂尔多斯盆地华庆地区长9油层组的微观特征,利用铸体薄片、扫描电镜、毛细管压力曲线等资料对储层微观孔隙结构进行深入研究。研究认为:华庆地区长9油层组以长石砂岩和岩屑长石砂岩为主,填隙物主要为胶结物,其中以铁方解石、浊沸石、伊利石和绿泥石为主;孔隙类型主要为原生残余粒间孔、溶蚀粒间孔、溶蚀粒内孔和自生矿物晶间微孔隙。依据毛细管压力曲线及孔隙特征将孔隙结构划分为5种类型:Ⅰ类(低门槛压力-中细喉型)、Ⅱ类(较低槛压力-细喉型)、Ⅲ类(较高门槛压力-微细喉型)、Ⅳ类(较高门槛压力-微喉型)、Ⅴ类(高门槛压力-微喉型)。

For determining the micro characteristics of Chang 9 reservoir in Huaqing area,the micro pore structure characteristics are studied based on the data analysis of casting slices,scanning electrion microscope and capillary pressure curves,et al. The study results show that the rock types of Chang 9 reservoir in Huaqing area are mainly feldspathic sandstone and debris feldspathic sandstone,the pore were mainly filled with cements,of which the main types are iron calcite,laumontite,illite and chlorite. The pore types are mainly primary residual intergranular pore,intergranular dissolved pore,intragranular dissolved pore and authigenic intergranular micropores. The pore structure is divided into five types according to the capillary pressure curves and pore characteristics: Type I has low threshold pressure and medium-fine throat; Type II has lower threshold pressure and fine throat; Type III has high threshold pressure and micro fine throat; Type IV has higher threshold pressure and micro throat; Type V has high threshold pressure and micro throat.