摘要：

探讨了沉积和剥蚀作用对孙虎地区油气生成、聚集的影响，认为两者对于本区油气的生成、聚集和保存都不太有利。首先，在沉积演化中缺少深湖相沉积，只在孔店组和沙河街组发育干盐湖相和滨浅湖相沉积，使得本区的油源有机质丰度不高，类型较差。其次，在洼陷边缘发育的冲积体系由于距油源远，缺少连通通道而难以成为良好的储集岩。另外，本区地层在老、新第三纪之间遭受的强烈抬升剥蚀（最大剥蚀厚度达3000 m），对本区的油气生成和聚集更是产生了严重的负面影响：一方面导致源岩层的温度、压力下降，油气生成、排出作用大大减弱；另一方面，使得已排出并聚集成藏的油气遭到破坏。强烈的构造活动导致了埋藏史的差异，本区可划分出3种类型的埋藏史，即持续沉降型、早期沉降型和二次沉降型。持续沉降型埋藏区地层埋藏较浅，只有沙三段局部地层进入生、排烃门限，生烃潜力不大；早期沉降型埋藏区地层埋藏较深，孔店组和沙三段均具有生排烃能力，但早期排出的烃存在一个保存问题；二次沉降型埋藏区经历了两次大幅度的沉降，均达到了生排烃门限，具有二次生排烃过程，是目前圈闭条件下寻找油气的较理想地区。

Abstract:

The sedimentation and erosion in the study area mostly have negative effects on hydrocarbon generation and accumulation. Firstly, in the process of sedimentation, deep lake facies did not occur. The playa and shallow lake deposits in the Kongdian and Shahejie formations provide the main source rocks, however, their low organic abundances make them poor source rocks. Secondly, coarse alluvial deposits in the marginal area of the depression are far away from source rocks and lack links with source rocks, so usually can not act as good reservoir rocks. Furthermore, the intensive uplift and erosion (up to 3000 m in thickness) at the end of the Palaeogene had severe negative effects on hydrocarbon accumulation. On one hand, it caused decline of temperature and pressure, and resulted in slowdown of hydrocarbon generation and expulsion from source rocks; on the other hand, it destroyed the earlly formed oilgas pools. The strong tectonic activities also resulted in difference in burial history. Three types of burial history have been identified, i.e. continuous subsiding type, early subsiding type and twice subsiding type. In the continuous subsiding region, the potential for hydrocarbon generation and expulsion is limited due to shallow burial depth, and only part of the third member of the Shahejie Formation (Es3) fall into oil window. In the early subsiding region, both the Kongdian Formation (Ek) and the Shahejie Formation fall into oil window, but preservation of the expulsed oil and gas is a problem. The regions underwent twice subsiding in burial history are the most prospective targets since source beds could maturate in each subsiding process.