石油学报 ›› 1983, Vol. 4 ›› Issue (4): 1-10.DOI: 10.7623/syxb198304001

• 地质勘探 •    下一篇

不整合对于油气运移聚集的重要性

潘钟祥   

  1. 武汉地质学院北京研究生部
  • 收稿日期:1982-03-08 出版日期:1983-10-25 发布日期:2013-07-08

SIGNIFICANCE OF UNCONFORMITY TO OIL AND GAS MIGRATION AND ACCUMULATION

Pan Zhongxiang   

  1. Beijing Graduate School of Wuhan College of Geology
  • Received:1982-03-08 Online:1983-10-25 Published:2013-07-08

摘要: 文中所谓的不整合,包括非整合、不整合和假整合。我国已经发现了不少与不整合有关的油、气藏。有的油藏位于不整合面上,有的油藏在不整合面上的沉积底部砂砾岩或底砂岩中,有的则是由不整合面封闭形成的地层油藏,也有的是基岩或潜山油藏。在不整合面的上下,油藏和气藏广泛分布的原因,主要是因为不整合下面的岩层经长期风化侵蚀溶解淋滤,岩石的孔隙性和渗透性均有所增强。由于不整合系油、气长距离运移的通道,它能把不整合面上下相距甚远的生油岩和储集岩互相联系起来。再加上在不整合上下分布有类型众多的圈闭。石油和天然气在从生油区沿不整合面运移的过程中,就聚集在圈闭之中,形成了类型众多的油、气藏。由于二次生油,不整合对于油、气破坏可能不大。所以不整合对于油、气的运移和聚集是非常有利的。

Abstract: The concept of unconformity used in this paper includes nonconformity, unconformity and disconformity. It is pointed out that quite a number of oil and gas pools related to unconformity have been discovered in China. some occur above the unconformity surface, some are in the basal conglomerates or sandstones above the unconformity surface, some belong to the stratigraphic traps sealed by the unconformity surface and some are in the basement rocks or buried hills under the unconformity. The widespread distribution of oil and gas pools above or below the unconformity surface may be attributed to the following five causes: 1. The rocks that are beneath the unconformity were subjected to a long period of weathering and erosion that increased their porosity; 2. unconformities usually act as passage-ways for the long distance migration of oil and gas; 3. the unconformity acts as a "bridge" to connect the source rock and reservoir rock whick occur either above or below the unconformity; 4. there are numerous better reservoir rocks, numerous conditions for forming traps, and various kinds of traps both above and below the unconformity; 5. owing to the second crop of off, the possibility of destroying oil and gas by the unconformity is probably not great. Therefore, the unconformity is extremely favorable for the migration and accumulation of oil and gas.