辽河坳陷西部凹陷雷家湖相碳酸盐岩沉积环境  

Sedimentary Environment of Lacustrine Carbonate Rocks in Leijia Area in West Sag of Liaohe Depression

作　　者：单俊峰[1] 黄双泉[1] 李理[1] 

机构地区：[1]中油辽河油田分公司,辽宁盘锦124010

出　　处：《特种油气藏》2014年第5期7-11,151,共5页Special Oil & Gas Reservoirs

基　　金：国土资源部"全国油气资源战略选区调查与评价"子课题部分成果(2009QYXQ15-07-04)

摘　　要：以碳氧稳定同位素、微量元素、稀土元素及锶钕同位素分析测试手段为基础,综合分析了雷家沙四上亚段白云岩沉积环境。研究结果认为该区沉积水体咸度不高,为半咸水。锶来源主要受陆源硅铝质岩控制,并受房身泡组火山岩的蚀变影响。δCe具有弱—中度正异常的总体特征,-α含量与Sm含量比值与Ce异常相关性差,碳氧稳定同位素相关性好,14个样本姥植比的平均值为0.38。结果表明沉积作用发生在偏碱性条件的强还原性封闭湖盆环境中。该认识对该区致密油的勘探具有一定指导意义。On the basis of analysis and testing approaches of carbon-oxygen stable isotopes,trace elements,rare-earth elements and Sr-Nd isotopes,sedimentary environment of dolomite in upper Sha4 member in Leijia area was comprehensively analyzed. The results indicate that: 1Salinity of deposit water body in this area is lower,being brackish water; 2Sr source is controlled by terrigenous siallite,and affected by alteration of volcanic rocks in Fangshenpao Fm; 3δCe has overall feature of weak-middle normal anomaly; 4Ratio between lanthanum content and samarium content has poor correlation with Ce anomaly; 5Carbon-oxygen stable isotopes have good correlation; 6The average pristane /phytane ratio of 14 samples is 0. 38. It is suggested that deposition occurred in a closed lake environment with strong reducibility in alkaline-prone condition. This cognition has certain guidance for tight oil exploration in this study area.

关 键 词：沉积环境 碳氧稳定同位素 微量元素 稀土元素 锶同位素 雷家白云岩 

分 类 号：TE121[石油与天然气工程—油气勘探]