Study on the multi-stage charging and accumulation model of Chinese marine petroleum: Example from eastern Lungu area in the Tarim Basin.
中国海相油气多期充注与成藏聚集模式研究——以塔里木盆地轮古东地区为例

Marine sedimentary basins in China have undergone three phases of important tectonic changes in the end of Early Paleozoic, Late Paleozoic-Early Mesozoic and Late Cenozoic. These tectonic changes have exerted strong impacts on the hydrocarbon generation, migration, accumulation and on the occurrence and distribution of hydrocarbon reservoirs. The marine basins in China generally developed multi source rocks. Due to the much difference of their developing age and position, the time of hydrocarbon generation and expulsion between these source rocks is not often synchronous. It is existed that the characteristic of the multi-stage hydrocarbon-charging. Therefore, multi-accumulation of petroleum is an important characteristic of the marine basin in China. Under the influence of multi-stage structural movements, multi-stage accumulation results from multi-stage maturity and expulsing hydrocarbon of multi source rocks. The eastern Lungu area of Tarim Basin is a typical example of multiphase hydrocarbon accumulations in a marine basin of China. At present, it has been determined that three main accumulation stages including Late Caledonian, Late Hercynian and Late Himalayan period. The heterogeneity carbonate reservoir developed in eastern Lungu area, and forming trap-system of seam and holes. After the process of earlier and later structure actions, these traps did not experience big changes. Therefore, the charging-hydrocarbon of three stages has been retained. The three-stage process of hydrocarbon charging is also confirmed by the analysis of geochemical data. Through the geological analysis, the process of hydrocarbon accumulation reappears. And, the model of marine multi-stage hydrocarbon-charging and accumulation is established.