构造体制转换与成藏作用——以鄂尔多斯盆地为例

构造体制转换在控制油气成藏中起着决定作用。其对成藏的控制作用可分为直接和间接2种方式。前者指构造体制转换使盆地构造应力场强度和性质发生变化，于盖层岩系中发育各种形式褶皱和断裂构造，组成了流体输运一定位网络，使物质和能量在盆地内重新分布；而后者指构造体制转换引起盆地沉积场、温度场及化学场等变化，并最终控制油气生、运、储。通过对鄂尔多斯盆地典型实例的剖析，认为多板块相互作用是盆地大规模成藏作用发生的根本动力，它控制着盆地的构造演化和沉积充填样式；同时，致使盆地不同部位形成差异升降和反转构造2种不同的构造样式。盆地中部构造作用微弱地带形成差异升降，而盆地边缘构造作用强烈部位发育反转构造。受其控制，盆地中部以构造-岩性圈闭为主，而盆地边缘则发育构造圈闭。抬升作用形成的区域不整合以及构造反转作用形成的断裂和裂隙系统，构成了油气运移的主要通道；油气发生垂向和侧向运移，最终在反转构造上升盘或隆起与坳陷转换部位聚集。

Transformation of tectonic framework and reservoir - forming process——taking Ordos Basin as an example

Transformation of tectonic framework plays a decisive role in all factors constraining on hydrocarbon reservoir formation.The control can be divided into direct and indirect ways.The former refers to;after the transformation of the tectonic framework,the changes of the strength and the property of tectonic stress field in the basin results in the development of various folds and faults in caprocks,which made up the fluid transportation-emplacement network and redistributed the substance and the energy in the basin.Whereas the later indicates that the transformation of the tectonic framework causes the field changes of basin sedimentation,temperature and chemistry,and finally determines the generation,migration and accumulation of oil and gas.Ordos Basin is taken as a typical example.Interaction of multi-microplates,which directly controls the tectonic evolution and filling styles of the basin,is the fundamental dynamics of hydrocarbon accumulation at large scale in Ordos Basin.In addition,it forms two different tectonic styles of differential fluctuation and inversion structures in different parts of the basin.The central part of the basin with weak deformation is dominated by differential fluctuation structures.Whereas,the border part of the basin with strong deformation is occupied by inversion structures.As a result,the former is characterized by structural-lithologic trap;while the later is featured by structural trap.Regional unconformity formed by uplifting effect,and fault-fracture system resulted from structural inversion,establishing the chief pathways for the migration of hydrocarbon.The hydrocarbon transported vertically and laterally,and finally accumulated at the upthrown block of the inversion structure or the transition part of uplifts and depressions.