汤原断陷断裂构造特征及油气成藏特点

汤原断陷是典型的受断裂控制的新生代陆相断陷盆地,盆地内断裂非常发育,主要为NE、NEE、EW和NW四个方向。根据目前钻探结果分析,断陷油气主要分布在汤原断陷中轴线以东的中央凸起带和东部凹陷带,紧邻东兴和东发次凹。油气藏类型主要发育构造油气藏、构造岩性油气藏,预测可能还发育潜山油气藏、地层超覆油气藏和岩性油气藏。油气控制因素分析认为:制约汤原断陷油气聚集成藏的主控因素是烃源岩的发育与分布,构造是油气聚集的重要因素。油气勘探的方向和有利区为:在层系上应首先优选古近系的达连河组、新安村组及乌云组;在平面上应优选东兴和东发次凹及其上倾方向。

Fault structural features in Tangyuan depression and its oil and gas accumulation

Tangyuan depression was a typical nonmarine fault basin in Paleogene, which was controlled by the faults and developed a variety of fractures with four directions in NE, NEE, EW and NW. According to the analysis of the present drilling data, the oil and gas accumulate to the east of central axis line in the depression and mainly in the central arch zone and eastern sags, which are very close to Dongxing and Dongfa sub-sags. The reservoir type of the Tangyuan depression mainly consists of structural reservoir, structural-lithological oil and gas reservoir, buried hill oil and gas reservoir, stratigraphic reservoir and lithological reservoir. With the analysis of the oil and gas controlling factors, it is considered that the main reasons for controlling the accumulation and forming reservoirs of the Tangyuan depression are the development and distribution of the source rock, and the structure is important factor of oil and gas accumulation. The most favorable potential formations locate in Tertiary, including the Dalianhe Formation, Xinancun Formation and Wuyun Formation. The most favorable potential structures locate in Dongxing and Dongfa sub-sags with their updip direction.