摘要
南堡凹陷是渤海湾内小型断陷盆地,近年来油气勘探取得不断突破。相对而言,对于其整个盆地构造和沉降演化规律的认识仍十分薄弱,而研究构造活动控制下的沉降史对于研究油气特征及有利区带的预测具有重要的意义。采用回剥法对南堡凹陷的构造沉降速率进行恢复,在此基础上进行了构造期次的划分。研究认为受到区域构造运动的控制,南堡凹陷总体上可以划分为裂陷期、凹陷期和裂后加速沉降期三个阶段,其中古近系整体表现为幕式沉降的特征,即Es_3^(4+5)为裂陷Ⅰ幕、Es_3~3-Es_2为裂陷Ⅱ幕、Es_1为裂陷Ⅲ幕、Ed_3-Ed_1为裂陷IV幕。回剥法是进行地史恢复的有效方法,为研究构造活动控制下的沉降史提供了理论基础。
Nanpu Sag is a small scale fault basin in Bohai bay, and great breakthrough has been made in recent years in oil and gas exploration. Comparatively speaking, the understanding about the basin structure and subsidence evolution is poor. The research of subsidence history is very importance for the research of oil and gas and forecast the favorable structural belts. With back stripping method, tectonic subsidence rate of Nanpu Sag has been restored, and the phases of tectonic activity have been divided. Controlled by tectogenesis, the tectonic subsidence of Nanpu Sag can be divided into three phases, including rifting phase, depression phase, and post rift accelerated subsidence phase. Paleogene is charactered by episodic subsidence. Es34＋5 is phase I rifting episode, Es33-Es2 is phase II rifting episode, Es1 is phase III rifting episode, Ed3-Ed~ is phase IV rifting episode. Back stripping method is an effective method for geohistory restoration, providing theoretical basis for the research of subsidence history.
出处
《海洋石油》
CAS
2012年第3期29-32,共4页
Offshore Oil
关键词
南堡凹陷
幕式沉降
沉降速率
回剥法
Nanpu Sag
episodic subsidence
subsidence rate
back stripping method
