碳同位素类型曲线在辽河盆地油源对比中的应用

Application of carbon isotope typical curve to oil source correlation in Liaohe basin.

方法 利用原油及其组分中碳同位素值所构成的同位素类型曲线 ,对辽河盆地东、西部凹陷两个不同地区的原油进行油 油和油 源对比。目的 区分来自不同母岩的原油 ,并根据碳同位素类型曲线判断油源。结果 西部凹陷高升雷家地区未熟低熟油与东部凹陷南部地区原油类型曲线分布特征差别明显。高升雷家地区未熟低熟油来自沙四段源岩 ,东部凹陷南部地区原油主要来自沙三段 ,部分来自沙一段 ,这与用其它地球化学指标得出的结论相吻合。结论 碳同位素类型曲线是一种非常有用的油 油和油 源对比的地球化学指标 ,与其它地球化学方法相比更直接、更有效 ,在辽河盆地油源对比应用中取得了良好的效果。

Method\ Oil-oil and oil-source correlation of the crude oil from eastern and western depressions in Liaohe basin are completed, by means of the isotopic type curves derived from carbon isotopic values of crude and its compositions. Purpose\ To identify the crude oil from different parent rocks and determine the source according to carbon isotopic type curve. Result\ There is a clear difference of type curve distribution characteristics between the immature and low mature oil in Leijia area of Gaosheng oilfield in western depression, from the source of the fourth member of Shahejie Formation, and the crude oil of south part of eastern depression, mainly from the source of the third member of Shahejie Formation and partly from that of the first member of Shahejie Formation. The result conforms to that obtained from other geochemical indicators. Conclusion\ Carbon isotopic type curve is a useful geochemical indicator for oil-oil and oil-source correlations, which is more direct and effective than the other methods. Its application to the oil-source correlation in Liaohe basin is very successful.