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合肥盆地是中国东部目前勘探面积最大、勘探程度最低的复合型残留盆地。本文简要地介绍了合肥盆地的构造演化历史,并利用野外露头资料、沉积学资料和地震资料进行综合研究,论证了晚白垩世内幕存在一次大规模的由南向北的挤压推覆运动,并建议将该期构造运动命名为燕山运动古城幕;通过对下侏罗统防虎山组和下白垩统朱巷组烃源岩主要生烃过程的分析,认为下侏罗统防虎山组烃源岩在晚侏罗-早白垩世时开始生烃,下白垩统朱巷组烃源岩主要在燕山运动古城幕之前开始生烃。燕山运动古城幕对下侏罗统防虎山组烃源岩形成的油气有利也有弊,有利的一面是利于所生成油气的排烃,不利的一面是早期聚集形成的油气藏可能遭到改造和破坏;对下白垩统朱巷组烃源岩形成的油气,主要排烃期与圈闭形成期相匹配,有利于油气的排烃和聚集成藏,据此指出了合肥盆地大桥向斜的勘探思路,即应以寻找古背斜及其上形成的披覆构造以及浅层的盖层条件较好的构造圈闭,这种类型的圈闭受构造运动改造较弱,保存条件较好,是寻找原生油气藏的主要勘探目标区。
The Hefei Basin is the compound residual basin with the largest exploration area and the lowest exploration level in eastern China. This paper briefly introduced the tectonic evolution history of the Hefei Basin and conducted a comprehensive study using the field outcrop data, sedimentary data and seismic data to demonstrate that there was a large-scale thrust nappe movement from south to north in the Late Cretaceous, It is suggested that the tectonic movement of this period be named the Yanshanian ancient city curtain. Based on the analysis of the main hydrocarbon generation processes of the Lower Jurassic anti-Hulushan Formation and the Lower Cretaceous Zhuxiang Formation, it is considered that the lower Jurassic anti-tiger group Source rocks began to produce hydrocarbons during Late Jurassic to Early Cretaceous. Source rocks of Zhulao Formation in Lower Cretaceous began to generate hydrocarbons mainly before the curtain of Yanshan movement. The Yanshan movement ancient city curtain has advantages and disadvantages to hydrocarbon generation from the source rocks of the Lower Jurassic Fanghushan Formation, and on the positive side is conducive to the hydrocarbon expulsion. The unfavorable aspect is that the reservoirs formed by early accumulation may be transformed and The hydrocarbon generation formed by the source rocks of the Zhula Formation of Lower Cretaceous matches the main hydrocarbon expulsion period with the trap formation period, which is favorable for the hydrocarbon expulsion and accumulation. According to this, the exploration of the syncline of the Hefei Basin bridge The idea is to look for paleo anticlines and the drape structures formed thereon as well as the shallow caprock with better structural traps. This type of trap is reformed by the tectonic movement weaker and the storage conditions are better. Find the main exploration target area of the original oil and gas reservoirs.