QEMSCAN矿物定量分析技术在成岩作用研究中的运用:以扶余油层致密砂岩为例

QEMSCAN Mineral Quantitative Analysis of Tight Sandstone Diagenesis in Fuyu Oil Layer,Daqing Placanticline

成岩作用强度和类型对非常规油气勘探开发具有重要影响,为详细刻画矿物和成岩作用特点,以扶余油层致密砂岩为研究对象,通过QEMSCAN矿物定量分析技术对样品进行了扫描分析,认为QEMSCAN分析技术能详细刻画致密砂岩中矿物的组成、含量、粒度和接触关系等,测试结果准确,数据可靠;研究区致密砂岩主要由石英、斜长石和碱性长石矿物组成,岩石类型为细粒岩屑长石砂岩;根据岩相学特征确定成岩共生序列由早到晚依次为:混合黏土(机械渗滤黏土)-绿泥石-长石的溶蚀、溶解作用-高岭石-伊利石-斜长石的钠长石化-黄铁矿-方解石;不同元素在矿物中的含量存在差异,具有相同元素组成的相邻矿物之间存在转换关系;QEMSCAN分析技术在致密砂岩中的运用对非常规油气勘探具有重要的理论和实际意义。

Diagenesis intensity and types have an important influence on the exploration and development of the unconventional oil and gas.This paper takes the tight sandstone in Fuyu oil layer as the research object and studies the characterization for mineral occurrence and diagenesis by the QEMSCAN mineral quantitative analysis.The analysis results show that QEMSCAN analysis technique can depict the mineral composition of tight sandstone in detail,such as content,granularity and contacts,with accurate and reliable test results.Tight sandstone is mainly composed of quartz,plagioclase and alkali feldspar,a rock type for fine grained lithic feldspar sandstone.Based on the petrographic characteristics,the sequence from early to late diagenetic symbiosis is determined in the order：mixed clay（mechanical infiltration clay）,chlorite,feldspar dissolution,kaolinite,illite,albitization of plagioclase,pyrite,calcite.Different elements in the mineral content is different,which have the same conversion relations between adjacent mineral elements.This research confirms that the technology of QEMSCAN analysis for the tight sandstone has an important theoretical and practical significance for unconventional oil and gas exploration.