海拉尔盆地不整合的形成及其油气地质意义

基于不整合与油气有密切的关系，首先阐述了采用地质、地震、测井资料所识别的不整合面，并将其分为区域不整合和局部不整合2种主要类型，探讨其成因认为，不整合的形成与频繁构造活动、长期遭受风化剥蚀、大气水淋滤等有关。然后指出：与不整合有关的油气藏为变质岩侵蚀残丘、顺向断块风化壳、地层不整合遮挡等类型，且具有高凸起上的低断块和低凸起上的高断块易于聚集油气的分布规律；不整合面易于形成高孔渗带，既可以改善储集体的渗透性，又是油气二次运移的良好通道；不整合对油气的生成和成熟有一定的影响。最后，预测斜坡带上发育的地层超覆不整合油气藏是下一步勘探的方向。

The Formation of Unconformity and Its Oil/Gas Geological Significance in Hailar Basin

There are close relationships between unconformity and oil/gas reservoirs.This paper elaborates how to identify unconformity with geological, seismic and well logging data.The unconformity is mainly divided into two types,regional unconformity and local unconformity.The origin of the two types of unconformity is discussed.The author thinks that the formation of the unconformity is related to frequent tectonic activities,long term weathering and erosion,and meteorological water leaching.This paper shows that there are several kinds of oil/gas reservoirs related to the unconformity such as metamorphic rock erosion monadnock,consequent fault block weathering layer,stratigraphic unconformity barrier etc.The oil/gas is distributed in the low fault block of the high uplift and the high fault block of the low uplift where oil/gas is easily accumulated. The high porosity-permeability belt is formed on the unconformity. The unconformity not only improves the reservoir permeability but also is good pathways for secondary oil migration. In addition, it influences oil formation and maturity to a certain extent. This paper predicts that the stratigraphic overlap unconformity reservoir can be developed on the slop and is the next exploration objective.