海拉尔盆地乌尔逊-贝尔凹陷构造演化对油气成藏的控制作用

从成盆、成源、成烃和成藏4个方面对海拉尔盆地乌尔逊-贝尔凹陷各构造演化阶段的石油地质意义进行了分析。海拉尔盆地成盆的动力机制是中蒙边界区中生代推覆构造形成后的晚造山期伸展垮塌作用，为典型的被动裂陷盆地。乌尔逊-贝尔凹陷形成演化经历了5个时期：山间残留阶段、被动裂陷阶段、主动裂陷阶段、断坳转化阶段和坳陷阶段。被动裂陷阶段沉积物震荡式沉积形成南一段中部砂泥互层的优质烃源岩，主动裂陷阶段盆地强烈裂陷，窄而深的断陷结构控制盆地南一段上部有效源岩分布，断坳转化阶段盆地快速沉降促进烃源岩熟化，伊敏组沉积晚期烃源岩大量排烃控制形成早期原生油藏，伊敏组末期盆地反转，部分油藏受活动断裂破坏调整到大磨拐河组形成次生油藏。不同演化阶段形成多种类型的隆起带，构成有利的油气聚集区带，控制了不同含油气系统油气聚集。

Controls of structural evolution on the hydrocarbon accumulations of Urxun-Beier Depression,Hailar Basin

From "basin formation,source rock,hydrocarbon generation and petroleum accumulation" four aspects,each stage of structural evolution and their significance to petroleum geology of Urxun-Beier Depression in Hailar Basin are discussed. Dynamic mechanism of the basin formation is the role of late-orogenic extensional collapse after Mesozoic orogeny formed in the Sino-Mongolian border area,so the Hailar Basin nucleated as a passive rift basin. Tectonic evolution of Urxun-Beier depression experienced five stages including:intermountain residual basin stage,passive rift basin stage,active rift basin stage,rift-depression transformation stage and depression stage. During the passive rift stage,sediments of the middle member 1 of Nantun Fm.(K₁n¹)concussively deposited and are characterized by interbedded mudstone and sandstone,which is the excellent source rock, During the active rift basin stage,basin strong rifted,narrow and deep depression framework controlled the distribution of effective source rocks in the upper K₁n¹, During the rift-depression transformation stage,rapid subsidence of basin showed significant positive impact on maturation of hydrocarbon source rock,massive hydrocarbon expulsed at the Late Yimin Fm.(K₁y)sedimentary period that control the primary reservoir's formation,at the end of the K₁y sedimentary period,inversion occurred in the basin,some early reservoirs was destructed by active faults and oil was regulated to the Damoguaihe Fm. to form secondary oil pools. There are diverse types uplift belts formed along with the basin evolution,which compose the difference hydrocarbon favorable accumulation belt and control the distribution of reservoirs in different petroleum systems.