摘要
以鄂尔多斯盆地东南缘Q地区长6储层为例，利用X射线衍射、剖面分析与鉴别等手段，从储层物性、岩石学特征、孔喉结构特征3个方面研究了储层的基本特征，并通过水驱实验研究分析了研究区致密砂岩储层的敏感性及主控因素。研究表明：鄂尔多斯盆地东南缘Q地区长6致密砂岩储层岩性主要为长石砂岩，粒度以细砂岩为主，储层物性较差，储层孔隙类型主要为粒间孔、长石溶孔，喉道类型主要为片状、弯曲状和缩颈状，喉道连通性较差。 综合考虑物性、孔隙类型及毛管压力曲线特征，将Q地区长6储层划分为3类，其中I类储层是该区储集能力和渗流能力最好的储层；研究区储层具有中—弱速敏性、中等水敏性、弱—中—弱盐敏性、中—强酸敏性、弱碱敏性的特征。
关键词： 致密砂岩储层；储层特征；敏感性研究
Abstract
Taking Chang 6 reservoir in Q area of the southeast edge of Ordos basin as an example, the basic characteristics of the reservoir are studied from three aspects of reservoir physical properties, petrological characteristics and pore throat structure characteristics by means of X-ray diffraction, section analysis and identification, and the sensitivity and main control factors of the tight sand reservoir in the study area are studied and analyzed by water drive experiment. The results show that the lithology of Chang 6 tight sandstone reservoir in Q area of the southeast edge of Ordos basin is mainly feldspathic sandstone, and the grain size is mainly fine sand. The physical property of the reservoir is poor. The pore types of the reservoir are mainly intergranular pores and feldspar dissolved pores. The main throat types are flaky, curved and necked, and the throat connectivity is poor. Based on the physical properties, pore type and capillary pressure curve characteristics, the Chang 6 reservoir in Q area is divided into three types, of which, Type I reservoir is the reservoir with the best reservoir capacity and seepage capacity in this area. The reservoir in the study area is characterized by medium to weak velocity sensitivity, medium water sensitivity, weak to medium to weak salt sensitivity, medium to strong acid sensitivity and weak alkali sensitivity.
Key words： Tight sand reservoir; Reservoir characteristics; Sensitivity study
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