金湖凹陷铜城断层构造特征与油气成藏

铜城断层是苏北盆地金湖凹陷中一条二级断层,表现为明显的分段性,南段为逆断层,北段为正断层。关于铜城断层的性质及构造演化,长期以来存在不同的认识。基于地震剖面解释的构造分析并结合走滑断层的鉴别标志,认为铜城断层为一典型的走滑断层。走滑作用造成了断层倾向沿走向发生变化,正逆两种断层交替出现。铜城走滑断层不仅有利于形成一系列不同类型的圈闭,而且对低渗透储集层具有明显的改善作用,其伴生的构造圈闭是有利的油气聚集场所。

STRUCTURAL CHARACTERISTICS OF TONGCHENG FAULT AND HYDROCARBON ACCUMULATION IN JINHU SAG

Tongcheng Fault is a second class fault which controlls the development of Tongcheng structural belt in Jinhu Sag. It is divided into two parts by its faulted feature showing reverse fault character at the south part and normal fault feature at the north part. There are different views about its character and evolvement. Tongcheng fault is considered as a typical strike-slip fault based on the structural analysis of seismic profiles. Varied directions of dip result in normal fault and reverse fault alternatively occurring along the fault because of strike-slip movement. Tongcheng strike-slip fault can not only form different types of traps, but also improve physical property of low-permeability reservoir, which is of great advantage to oil and gas accumulation.