川西坳陷丰谷构造须四段沉积微相及沉积演化  

Sedimentary microfacies and sedimentary evolution of the fourth section of Xujiahe Formation in Fenggu Structure,West Sichuan Depression

作　　者：林煜[1,2] 徐樟有[1,2] 吴胜和[1,2] 张文彪[1,2] 郁智[3] 

机构地区：[1]中国石油大学(北京)地球科学学院,北京102249 [2]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [3]中国石油吉林油田分公司勘探开发研究院,吉林松原138000

出　　处：《断块油气田》2011年第6期718-721,共4页Fault-Block Oil & Gas Field

基　　金：国家油气重大专项子项目"碳酸盐岩礁滩相储层预测技术"(2008ZX05017-001-01-03HZ);中国石油石油科技中青年创新基金"基于岩石物理相理论的天然气优质储层预测方法研究"(07E1002)

摘　　要：川西坳陷丰谷构造须家河组四段属典型的陆相含煤地层,广泛发育辫状河三角洲沉积。首先根据岩心描述、岩石薄片观察及砂体测井曲线形态分析等,在须四段识别出水下分流河道、分流河道间、河口坝、远砂坝、水下天然堤和前三角洲泥等6种沉积微相;其次针对丰谷构造井资料较少、砂泥岩速度差异不大的特点,采用神经网络的地震多属性反演得到自然伽马数据体;最后,以次为约束,建立泥质质量分数三维模型,预测泥质质量分数的空间变化,分析沉积微相演化规律。研究表明:须四段垂向经历了完整的水进—水退过程;沉积早期和晚期砂体较厚,主要为多期水下分流河道的拼接和叠置;沉积中期砂体相对较薄,发育河口坝与残余水下分流河道,砂体间有厚度稳定的前三角洲泥。The fourth section of Xujiahe Formation in Fenggu Structure of western Sichuan Depression is typical continental coalbearing strata and widely develops the braided river delta. According to core description, rock slice observation, analysis of logging curve shape, underwater distributary channel, inter distributary, mouth bar, distal bar, underwater natural levee and prodeha mud are identified in the fourth section of Xujiahe Formation. In view of little well data and small velocity difference between sandstone and mud in Fenggu Stucture, the data volume of natural gamma is inverted by using multiple seismic-attributes inversion based on neural network. Three-dimensional model of shale content is established in order to predict the spatial variation of shale content and to analyze the evolution law of sedimentary microfacies. The results show that the fourth section of Xujiahe Formation experiences the complete process of transgression to regression. At the early stage and late stage of deposition, sand bodies are very thick and are mainly the splice and superimposition of muhiphase underwater distributary channel. At the middle stage of deposition, sand bodies are relatively thin and mouth bar and residual underwater distributary channel develop and stably thick prodelta mud distributes among sand bodies.

关 键 词：多参数反演 沉积微相 演化规律 须四段 丰谷构造 

分 类 号：TE112.2[石油与天然气工程—油气勘探]