南贝尔凹陷东次凹北洼槽南屯组一段储层特征

Characteristics of Reservoir in Nan 1 Section in North Frog of East Sub-sag of South Buir Oilfield

南贝尔凹陷东次凹北洼槽位于蒙古人民共和国东方省境内,主要油层为南屯组一段Ⅱ油组(K1n1Ⅱ),其次为南屯组一段Ⅲ油组(K1n1Ⅲ)及南屯组一段Ⅰ油组(K1n1Ⅰ),通过薄片、扫描电镜、x衍射分析和测井解释等手段,对南屯组一段Ⅱ、Ⅲ油组储层的岩石学特征、物性和孔隙结构特征进行了分析研究。该层位岩性主要为火山碎屑岩,孔隙类型主要为完整粒间孔隙、溶蚀孔隙,属于低孔低渗-中孔中渗储层。依据储层分类评价标准,结合普通物性分析及压汞分析的孔隙度、渗透率资料,并结合相应的压汞参数进行储层分类评价。研究表明,南屯组一段Ⅲ油组储层类型为Ⅲ类,南屯组一段Ⅱ油组储层类型为Ⅱ类。

North frog of east sub-sag of South Buir Oilfield is located in the Eastern Province of the People＇s Republic of Mongolia.Main oil reservoir is pay zoneⅡof Nan1 section（K1n1 II）,followed by pay zone Ⅲ of Nan1 section（K1n1III） and pay zone I of Nan1 section（K1n1I）.For the purpose of studying the petrological characteristics,physical properties and pore structures of the reservoir of pay zone Ⅱ and Ⅲ of Nan1 section,a large numbers of scanning electron microscopes,thin sections,casting thin sections and well logging data were analyzed.Pyroclastic rock is the main lithology of this area,pores in the Nan1 section are mainly complete intergranular pores,dissolved pores,the formation is a reservoir of lower porosity and permeability to intermediate porosity and medium permeability.Classified evaluation shall be carried out to reservoirs,according to standard of reservoirs classified evaluation,porosity and permeability data of ordinary physical property analysis and mercury injection data analysis,and corresponding mercury injection parameters.Comprehensive evaluation of reservoirs at pay zone Ⅲ is type Ⅲ,reservoirs of pay zoneⅡ is type Ⅱ.