鹤山凹陷烃源岩分布特征研究

Distribution characteristics of hydrocarbon source rock in Heshan Sag

石宁 袁立忠 刘军 宋建虎 张建强 刘莹

中海石油（中国）有限公司深圳分公司，广东 广州 510240 CACT作业者集团，广东 深圳 518067 中国石油大学（北京）地球科学学院，北京 102249

Shenzhen Branch of CNOOC Ltd., Guangzhou 510240, China CACT Operator Group, CNOOC Ltd., Shenzhen 518067, China College of Geosciences, China University of Petroleum, Beijing 102249, China)

鹤山凹陷地理上位于南海北部陆缘超深水区，地质上属于地壳强烈减薄的洋陆转换带之上，具有高地温梯度、岩石圈韧性变形等不同于陆架区凹陷的特殊地质条件，因而具有特殊的生烃成藏史。采用区域对比的方法，通过层序地层格架、地震相、沉积相等研究，对研究区古近系烃源岩分布特征进行了早期预测，认为在始新世中晚期鹤山凹陷为陆缘断陷湖盆沉积。凹陷中央、控凹断层下降盘局部地区发育沉积厚度较大的中深湖相沉积，具有低频、连续、强振幅、平行?鄄亚平行的地震反射特征，与白云凹陷已钻探证实的湖相烃源岩相似，具有良好的生烃潜力。

Heshan Sag locates in the ultra-deep water area of northern continental margin in South China Sea, on the ocean-continent transition zone with strong crustal thinning. The special geological conditions such as high temperature gradient and lithospheric ductile deformation are different from the depressions which are in continental shelf area, so Heshan Sag has special hydrocarbon accumulation history. Using the method of regional contrast and through the study of sequence stratigraphic framework, seismic facies and sedimentary facies, the distribution characteristics of Paleogene hydrocarbon source rock are predicted early. It is considered that Heshan Sag is a continental margin rift basin deposition in the Eocene period. The thickness of deep lake facies deposition is large in the central part of the sag and the local area of sag-controlling faults downthrown, showing the seismic reflection characteristics of low frequency, continuous, strong amplitude and parallel to subparallel, which are similar to the lake hydrocarbon source rocks drilled and confirmed in Baiyun sag. Therefore, the hydrocarbon source rocks in Heshan Sag have good hydrocarbon potential.

10.6056/dkyqt201305003