陕北斜坡中部长2储层主要孔隙类型及成岩作用的控制  

Main pore types and its diagenetic controls of Chang 2 reservoir in the middle part of North Shaanxi Slope,Ordos Basin

作　　者：赵永刚[1] 韩永林[2] 粱晓伟 方艳兵[3] 王帅[1] 

机构地区：[1]西安石油大学地球科学与工程学院,西安710065 [2]中国石油天然气集团公司长庆油田分公司第二采油厂,甘肃庆城745100 [3]中国石油天然气集团公司长庆油田分公司勘探开发研究院,西安710018

出　　处：《兰州大学学报（自然科学版）》2014年第1期31-38,共8页Journal of Lanzhou University(Natural Sciences)

基　　金：中国石油科技创新基金研究项目(2011D-5006-0103);陕西省自然科学基础研究计划项目(2009JM5002);西安石油大学博士科研启动项目(207003);国家科技重大专项计划项目(2011ZX05044-3)

摘　　要：通过岩心观察及岩石薄片鉴定,利用X–射线衍射、铸体薄片图像和扫描电镜等分析手段,结合大量的岩心孔渗数据,在研究陕北斜坡中部长2储层岩石学及物性特征的基础上,定性描述孔隙与定量分析孔隙构成相结合识别长2储层的主要孔隙类型,揭示孔隙特征,重点探讨这些主要孔隙类型的成岩作用控制机制.研究认为:长2储层整体上属于中孔低渗型细粒长石砂岩,多数孔隙中见绿泥石薄膜;主要发育粒间孔(包括残余粒间孔)、杂基内微孔、粒间溶孔、粒内溶孔(主要是长石、岩屑溶孔)、碳酸盐溶孔和晶间微孔等6类孔隙,其中粒间孔是最主要的孔隙类型,粒内溶孔是最主要的次生孔隙类型,杂基内微孔和晶间微孔的储渗意义不大;长21、长22储层的孔隙构成特征与长2储层的相似;粒间孔的保存主要受保持性成岩作用的控制,粒内溶孔主要是大气水淋滤作用的产物.早成岩阶段的自生绿泥石胶结、微晶石英胶结和碳酸盐矿物胶结都不同程度地保护了粒间孔;粒内溶孔则是与2次构造抬升剥蚀事件相对应的两期大气水淋滤作用的结果.By means of a core survey, rock section identification, of X-ray diffraction, rock cast section images and scanning electron microscope, combined with a large amount of porosity and permeability data of core and based on a study of petrology and physical property of Chang 2 reservoir, a qualitative description with a quantitative analysis was conducted to identify the pore components and main pore types; meanwhile, char-acteristics of these main pore types and their diagenetic controls were the focus in the middle part of North Shaanxi Slope. The research suggested that Chang 2 reservoir belongs to medium porosity, low permeability, fine arcose sandstone and chlorite coating is common in the sandstone. Six types of pore were observed and they are intergranular pore （residual intergranular pore）, micropore in matrix, intergranular dissolved pore, intragranular dissolved pore （feldspar, rock fragment dissolved pore）, carbonate dissolved pore and intercrystal micropore. Of them the intergranular pore is the most important pore type, intragranular dissolved pore is the most important secondary pore type, and the reservoir space and flow matrix of micropore in matrix and intercrystal micropore is inconspicuous. The pore component of Chang 21, Chang 22 reservoirs is similar to that of Chang 2 reservoir. Reservation of intergranular pore is controlled by retention processes. Intragranular dissolved pore is regarded as a result of atmosphere water eluviating. Autogenetic chlorite cement, microcrystalline quartz （silica） cement and carbonate mineral cement can preserve intergranular pore to a certain extent in the diagenetic stage. In-tragranular dissolved pore have resulted from two phrases of atmospher water eluviation corresponding to two tectonic uplift and denudation events.

关 键 词：粒间孔 粒内溶孔 保持性成岩作用 大气水淋滤作用 长2储层 陕北斜坡 

分 类 号：P618[天文地球—矿床学] TE122[天文地球—地质学]