群体包裹体地球化学特征及在油气源对比中的应用

Application of colonial inclusions geochemistry in oil-and-gas origin study

米敬奎 张水昌 何坤

Mi Jingkui Zhang Shuichang He Kun

中国石油勘探开发研究院实验研究中心, 北京, 100083 2. 中国石油天然气股份有限公司油气地球化学重点实验室, 北京, 100083 3. 中国石油勘探开发研究院, 提高石油采收率国家重点实验室, 北京, 100083

Experiment Research Center, Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China 2. Key Laboratory of Organic Geochemistry, Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China 3. State Key Laboratory of Hydrocarbon Recovery Factor, Research Institute of Petroleum Exploration and Development, PetroChina, Beijjng 100083, China

群体包裹体地球化学性质虽然不及单个包裹体地球化学特征能更准确地反映油气源及成藏方面的信息,但群体包裹体地球化学分析仍是目前技术条件下比较可靠的利用包裹体地球化学信息研究油气源的重要手段。通过对我国塔里木盆地志留系及鄂尔多斯盆地奥陶系盐下储层群体包裹体地球化学特征分析认为:塔里木盆地志留系砂岩包裹体中原油的生物标志物特征与目前保留下来原油的生物标志物特征一致,目前保留下来的原油来源于中、上奥陶统源岩;鄂尔多斯盆地龙探1井下古生界盐下包裹体中气体的地球化学特征与中部气田天然气的地球化学特征有较大差别,乙烷同位素差别更大,它不能反映天然气的来源。包裹体中与气藏中天然气地球化学特征对比说明鄂尔多斯盆地下古生界天然气的来源主要是煤成气。

Although the geochemical characteristics of colonial inclusions do not work as well as those of single inclusion in oil-and-gas origin and accumulation analyses, they are still reliable and important ways to study oil-and-gas origin at present. Studies of the geochemical characteristics of colonial inclusions in sandstone reservoir (Silurian, the Tarim Basin) and carbonate reservoir under salt layer (Ordovician, the Ordos Basin) indicated that, the biomarkers of crude oil from inclusions in sandstone reservoir (Silurian, the Tarim Basin) were the same as those of present saved crude oil which originated from the middle and upper Ordovician. The geochemical characteristics of gas in under-salt inclusions (well Longtan1, the lower Paleozoic, the Ordos Basin) were different from those of gas from the central gas fields. δ13 C2 could not demonstrate natural gas origin due to big changes. The geochemical comparison between gas from inclusions and gas from gas pools proved that the natural gas found in the lower Paleozoic of the Ordos Basin was coal origin.

中国石油科技创新基金项目(2008D-5006-01-02)

https://doi.org/10.11781/sysydz201102188