柴达木盆地构造圈闭特征与含油气性

Features and hydrocarbon potential of the structural traps in Caidamu Basin

构造是柴达木盆地油气分布的主要控制因素,构造圈闭的形成、发展与演化对油气聚集有着重要的控制作用.柴达木盆地构造圈闭以背斜、断背斜、断鼻和断块为主,主要分布在七个泉—油砂山—东柴山、红沟子—南翼山—碱石山—落雁山、冷湖零号—冷湖七号—马海以及中内部等4个NW走向的密集分布区带内.构造圈闭的平面展布主要受应力作用状况、构造变形程度和断裂发育状况等因素控制.平衡剖面复原结果表明构造圈闭主要开始形成于古新世和中新世,主要定型于中新世、上新世和第四纪.喜山运动控制了柴达木盆地西部地区构造圈闭的形成与演化过程.圈闭含油气性综合分析表明,生烃凹陷附近的古构造圈闭和同沉积构造圈闭应该是下一步油气勘探的重点领域.

Tectonic activities have strongly influenced the formation and distribution of hydrocarbon traps in Caidamu Basin.The structural traps,inclosing anticlines,fault-anticlines,fault-noses and fault-blocks,are the most important petroleum traps,which mainly distribute in four NW-striking domains.The plane distribution of the structural traps is controlled by stress,tectonic distortion and faults.The recovery results of balanced profiles show that the initial formation of the structural traps mostly occurrs in Paleocene and Miocene,and they evolve in Miocene,Pliocene and Quaternary.Himalaya Orogeny has important effects on the formation and evolution of the structural traps in the western Caidamu Basin.The integrated analysis of petroliferous traps demonstrates that the paleo-structures and the syndepositional traps near hydrocarbon-generating sags should be the key goals of oil-gas exploration in the future.