牛庄—八面河地区原油混源问题探讨及混合比计算

采用有机地球化学方法对牛庄—八面河地区混源油问题进行了研究。将来自沙三段成熟源岩的牛庄油田原油和来自沙四段源岩的八面河油田原油作为端元，通过伽马蜡烷含量/C30藿烷与藿烷/甾烷交会图、重排单芳甾/C27βS单芳甾比值和芳香甾含量交会图等方法，尝试计算了原油的混合比。计算结果显示从牛庄洼陷向八面河地区沙四段来源油的比例逐渐增加且两种方法计算的混合比一致。牛庄洼陷中心以沙三段来源油占绝对优势，八面河斜坡区则是以沙四段来源油为主，而王家岗地区则二者兼而有之。

Discussion on Oil Mixing and Calculation of Mixing-ratio in Niuzhuang to Bamianhe Area, Dongying Depression

It has been performed that investigating the mixed oil in reservoirs from Niuzhuang to Bamianhe oilfield with organically geochemical method. Using mature oil in Niuzhuang oilfield from Es3source rocks and low-mature oil in Bamianhe oilfield from Es4 source rocks as two end members, to make cross plots of gammacerane/C30-hopanoid ratio and hopanoid/sterane ratio, rearranged monoaryl sterane/C27 [3S monoaryl sterane ratio and the content of aromatic sterene, then calculated the oil mixed rate based on the cross plots. The result indicated that the mixing ratio of oil from Es4 source rocks step up from Niuzhuang sub-depression to Bamianhe oilfield, and got similar data from two cross plots. Mature oil form Es3 source rocks dominated in the centre of Niuzhuang sub-depression, low mature oil from Es4 source rocks dominated in Bamianhe oilfield, and two type oil mixed in Wangjiagang oilfield.