从地震信息看中国东部和中国中西部沉积盆地构造演化动力学与断块油气藏(下) 中国中西部盆地演化及断块(圈闭)油气藏

中国中西部地区以塔里木盆地及其演化为典型代表。震旦纪以来,经历了地台发育、持续沉降、拉张翘倾、挤压坳陷及断陷推覆等构造发育阶段,与中国东部一样,表现为拉张与挤压交互出现的手风琴式演化史,突出的差别在于晚喜马拉雅期在西部地区形成强烈的挤压逆掩推覆构造,而东部地区只形成坳陷式的沉积盆地。中亚—蒙古大洋、秦—祁—昆大洋、古特提斯洋、中特提斯洋、印度洋以及印度板块等在不同地质时期的板块活动是中国中西部地区盆地演化发展的动力学因素。根据地震剖面解释成果,可确定出四种断块油气藏类型,均反映后期挤压逆冲特征,尤其是燕山期—喜马拉雅期推覆前锋带断块油气藏,还可区分为拆离型、褶皱型、前冲型和反冲型等四种,且每一种还可再区分出若干种。

Basin Evolution and Faulted Block Oil & Gas Pools in Middle and Western Parts of China,Shown by Seismic Information/

Evolution of basins in the middle and western parts of China is represented by Tarim Basin.It has experienced the tectonic development stages of platform development,continuous subsidence,extension and titling,compression and depression,and fault depression and napping since Sinian period.Similar to the eastern part of China,the evolution history shows alternate occurring of extension with compression as an accordion in this region.The obvious difference from each other is that intensively compressive and thrusting structures formed during the late Himalayan orogeny in the western part while depressed sedimentary basins formed merely during this phrase in the eastern part.The plate movements in different geological history phrases are the dynamics of basin evolution and development in the middle and western parts of China.Based on the interpretation results of seismic profiles,four types of faulted block reservoirs can be classified and every type of reservoirs indicates the characteristics of compression and thrusting.Especially,the faulted block reservoirs of the Yanshanian-Himalayian nappe front belt can be classified into pull-apart,fold,front thrust and back thrust types,each of which may be also divided into several subtypes.