莺—琼盆地原油类型划分及成因探讨

THE DISCUSSION OF THE CRUDE OIL TYPE AND ITS ORIGIN INYINGQIONG BASIN

莺歌海盆地乐东和东方地区、琼东南盆地崖13-1构造原油的Mango轻烃参数和同位素组成有明显差异,这可能是油源不同或原油成藏分异效应不同所致。该两盆地原油的芳烃组成和分布也有差异,琼东南盆地原油高含联苯系列化合物,莺歌海盆地原油反之。将乐东和东方地区原油的类异戊二烯烃相互对比,发现同一盆地不同地区原油之间在成因上可能存在差别。东方1-1-5和乐东20-1-2井原油的脂肪酸组成和分布明显不同,前者以正构脂肪酸为主和低碳数化合物占优势;后者富含类异戊二烯酸和正构脂肪酸中高碳数化合物占有较高比例:表明两者成油母质的生源和沉积环境可能有差别。

Mango parameters and the evolution of parents and its children indicate that crude oil exists difference in Ledong and Dongfang area. It show they come from different source rock or have distinguishable effect during forming reservoir. The light hydrocarbon parameters of crude oil coming from Ya 13-1 structure vary between the parameters of two area crude oil which indicates kerogen matrix types and depositional environment are different. The difference of hydrogen and carbon isotope composition in Ledong and Dongfang crude oil shows the depositional environment of their source rock or changeable effect during forming reservoir are different. The biomarks parameters also make sure the discrepancy of crude oil property in two area and prove the same oil source that come from Ya 13-1 structure. The study of aromatic hydrocarbon and fatty acid obtained the same results.