下扬子黄桥地区龙潭组储层流体包裹体特征及油气成藏期研究

Fluid inclusion features and hydrocarbon accumulation stages of Permian Longtan Formation, Huangqiao area, Lower Yangtze Basin

陈顺勇 俞昊 林春明 张妮 张霞 倪培 丁俊英

Chen Shunyong Yu Hao Lin Chunming Zhang Ni Zhang Xia Ni Pei Ding Junying

内生金属矿床成矿机制研究国家重点实验室, 南京大学 地球科学与工程学院, 南京 210093 2. 中国石油化工股份有限公司 华东分公司, 南京 210036

Skate Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu 210093, China 2. SINOPEC East China Company, Nanjing, Jiangsu 210036, China

根据流体包裹体的透射光和荧光镜下观察,江苏黄桥地区二叠系龙潭组储层样品中包裹体较为发育,以盐水和油包裹体为主,主要分布于石英裂纹和石英次生加大边中,个体较小。油包裹体在蓝光和紫外光激发下分别发黄绿色和蓝白色荧光,表明研究区龙潭组油主要为中成熟阶段。通过对研究区包裹体显微测温,结合埋藏史—热史、构造演化和成岩演化模式研究,该区包裹体均一温度主要在89~93,115.4~126.3,135~147.6℃ 3个区间,认为黄桥地区龙潭组主要经历了3期油气充注:第一期为73~70 Ma(晚白垩世),第二期为58~52 Ma(古近纪早期),第三期为45~38 Ma (古近纪中期),以第二期和第三期为主。

Transmitted light and fluorescence microscopy observations of fluid inclusions indicate that fluid inclusions are widespread in the Permian Longtan Formation in Huangqiao area of the Lower Yangtze Basin, mainly aqueous and oil inclusions. They usually distribute in small sizes in quartz cracks and quartz secondary enlargement edges. Oil inclusions show yellow-green and blue-white fluorescents respectively with blueray and ultraviolet excitations, thus indicating that the oil in the Longtan Formation in the study area is primarily in middle mature stage. Through the microscopic temperature measurement of inclusions, combined with the burial history-thermal history, tectonic evolution and diagenetic evolution model researches, it has been concluded that the homogenization temperature of inclusions has 3 intervals, 89-93, 115.4-126.3 and 135-147.6℃. Hydrocarbons in the Longtan Formation in Huangqiao area have experienced 3 major filling periods: the first period for 73-70 Ma (the Late Cretaceous), the second period for 58-52 Ma (the Early Paleogene), the third period for 45-38 Ma (the Middle Paleogene). The second and third stages are most important.

国家自然科学基金项目(41272124);南京大学"内生金属矿床成矿机制研究国家重点实验室"自主研究基金项目(2009-Ⅱ-11)资助。

https://doi.org/10.11781/sysydz201304389