Source rocks of Wuerxun Depression of the Hailaer Basin were investigated to characterize their biological developments,organic geochemistry.Together with wire logs and well cores analyses,three series of high quality source rocks in Nantun Formation were discovered.They all have good organic types,high abundance of organic materials and high hydrocarbon potentials.Combined with geological setting and referred previous study,the criterion of high quality source rocks was established[(S 1 +S 2 ) 20mg/g,chloroform bitumen "A"> 0.3%,TOC>5.0% and HC>700×10 -6 ],which was fit for the whole study area.Through the method of organic carbon log,the distribution of high quality source rocks was confirmed,which showed that the high quality source rock was mainly developed as thin layere in the Nantun Formation,especially in the upper part.In short,the development of the high quality source rocks contributed greatly to the pool forming.

运用钻井岩心及测井资料,对海拉尔盆地乌尔逊凹陷烃源岩的生物发育、地球化学特征进行研究,认为乌尔逊凹陷南屯组发育有薄层优质烃源岩,它们有机质丰度高,类型好,生烃潜力大。结合研究区地质条件,并参考前人的研究成果,建立了适合本区优质烃源岩的评价标准;认为本地区烃源岩在生烃潜量(S 1 +S 2 )大于20mg/g,氯仿沥青"A"大于0.3%,TOC大于5.0%,总烃(HC)大于700×10 -6 的情况下为优质烃源岩;同时,运用有机碳测井评价方法,结合研究区优质烃源岩评价标准,分析了区内诸多钻井优质烃源岩的分布特征。结果表明,研究区优质烃源岩主要发育在南屯组,特别是该组的上部,南屯组一段烃源岩的厚度大于南屯组二段。总的来说,本区优质烃源岩的发育对盆地油气成藏产生较大的生烃贡献。

Beier depression is one of the most promising oil-bearing areas in Hailaer Basin with abundance of oil and gas resources． However，the reservoir forming conditions were complicated due to multi-period tectonic structural transformation． Ｒesearches suggested that Beier depression had experienced three-phases in basin forma- tion，and two-period tectonic transformations (by end of the Nantun Formation and by end of Yimin Formation)， which played key roles in the process of hydrocarbon accumulation． The source rocks controlled the distribution of oil and gas． Vertically，there were three sets of reservoir-seal assemblages，while Nantun Formation，with its inher- ent hydrocarbon generation and accumulation conditions，was the major formation for exploration． There were three hydrocarbon accumulation models，the gently sloping antithetic fault bench，the uplift zone between duplex half- graben fault depressions，and small deep sub-sags which provided good preservation conditions． Understandings on the controlling factors and rules of hydrocarbon accumulation provided favorable exploration targets of the south of Beixi slape belt the south of Sudeerte structural belt and sags of Beidong zone．

贝尔凹陷是海拉尔盆地富油凹陷之一，油气资源丰富，受多期构造运动改造，油气成藏条件复杂。研究表明，贝尔凹陷经历了 “早、中、晚”三期成盆及南屯组末、伊敏组末两期改造的构造演化过程。每期 “成盆与改造”对油气成藏起着关键性作用。有效烃源岩控制了油气分布范围; 纵向上发育三套储盖组合。南屯组自生自储型组合为主要勘探层系; 发育缓坡反向断阶带、复式箕状断陷间的断裂隆起带及保存条件好的小深洼槽三种成藏模式。油气成藏主控因素及富集规律的认识明确了贝西斜坡带南部、苏德尔特构造带南部及贝东洼槽群为下步重点勘探方向。

The Beier depression in the Hailaer basin is an extensional faulted depression of the Early Cretaceous epoch.Based on seismic data and well logs, the evolution of Beier depression is discussed in this paper.It is concluded that alternation of extension and shortening is occurred through the evolution of this depression.Development of three sedimentary cycles，superimposition of extensional and inversion structures, and formation of oil reservoirs were controlled by three activities of tension and compression in the Early Cretaceous epoch.In general, the processes of extension and shortening control the structural styles and sedimentary cycles, and also are responsible for the distribution of source-reservoir-cap rock assemblages, and the migration, accumulation and preservation of oil and gas.

贝尔凹陷是海拉尔盆地中一个早白垩世的伸展断陷，通过综合应用地震、钻井等资料对贝尔凹陷的形成及演化进行深入分析，认为伸展作用和缩短作用的交替进行贯穿了凹陷的演化过程，白垩纪发育的3个伸展作用幕和3个缩短作用幕控制了凹陷的3期沉积旋回、伸展构造与反转构造的叠加和油藏的形成。伸展作用和缩短作用控制着贝尔凹陷内的构造样式和沉积样式的形成与演化。从而影响着烃源岩、储集层的发育与分布，并制约着油气的运移、聚集和保存。

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.(K 1 n 1 )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 K 1 n 1 , 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.(K 1 y )sedimentary period that control the primary reservoir's formation,at the end of the K 1 y 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.

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。

The petroleum accumulation conditions of Damoguaihe Formation in the Urxun—Beier Sags of the Hailaer Basin were studied with stratigraphic,tectonic and accumulation system theories.The fractures in the study area experienced 3 stages of deformation including the extension during Tongbomiao and Damoguaihe periods,the strike-slip during Yimin period and the strong inversion during Qingyuangang and the late Paleogene periods.Damoguaihe Formation was divided into 3 third-grade sequences and 15 sand layers.Different stages controlled different sedimentary evolution processes.The crude oil in Damoguaihe Formation came from Nantun Formation and was closely related to the first member of Nantun Formation.There existed 2 ways of hydrocarbon migration.1)When the fault displacement was over 300 m,the source rocks in Nantun Formation connected with the reservoirs in Damoguaihe Formation,resulting in side-generating and side-reserving reservoirs.2)The hydrocarbon in Nantun Formation migrated upwards into Damoguaihe Formation,and then moved laterally for a short distance,forming lower-generating and upper-reserving reservoirs.The reservoirs in the region were classified into 4 types: tectonic,lithologic,stratigraphic and lithologic—tectonic.

运用地层学、构造地质以及成藏系统等理论和方法,系统阐述乌尔逊—贝尔凹陷大磨拐河组油气成藏条件。凹陷断裂经历了铜钵庙组—大磨拐河组沉积期的伸展变形、伊敏组沉积期的走滑变形和青元岗组沉积期—古近纪末期的强烈反转变形3个阶段。大磨拐河组地层划分为3个三级层序和15个砂岩组,各个时期控制着不同沉积演化过程。大磨拐河组原油来源于南屯组,与南一段关系密切,存在2种油气运移方式:1)当断距大于300m时,南屯组生油源岩与大磨拐河组储层对接,从而构成直接侧向运移的旁生侧储型油藏;2)油沿(不整合面)油源断层自南屯组向上垂向运移至大磨拐河组,再短距离侧向运移形成下生上储型油藏,总结油藏类型为构造、岩性、地层及岩性—构造4大类。

Based on the structural analysis principle, different boundary conditions forming different nature faults in the same stress field, indicate that the Hailar Basin is controlled by the SSE-NNW direction extensional stress field, forms NNE and NEE trending faults, and NNE trending faults express strike-slip deformation evident. Extensional stress field orientation adjusted to nearly EW direction, nearly SN trending faults formed, and NNE, NEE and SN trending faults twisted deformation in the stage of rift-depression transformation in Hailar Basin. The basin returned during the end of Yimin formation, emerged levorotation pressure torsion deformation controlled by nearly EW compressive stress field, and NNE and NEE trending faults inversed strong. Basis for fault deformation characteristics superposition relationship, there are 4 sets of fault systems in Hailar Basin: early extension faults, interim tensile shearing faults, early extension and interim tensile shearing faults and early extension, interim tensile shearing and late reversal faults. The early extension and interim tensile shearing reverse faults form fault sheltered traps, the uplifts within depression and slopes are cut and crushed into fault complication anticline traps, and the early extension faults and interim tensile shearing faults cross combination and form complex fault block traps in rift structure layer. The early extension, interim tensile shearing and late reversal faults, appearing \"comb-like\" composition, form typical fault block traps in the rift-depression structure layer. Based on the fault activity and accumulation period coupling relation and anatomy results of typical oil and gas reservoirs, concludes that the early extension faults and early extension and interim tensile shearing faults play sheltered faults at a critical accumulation time with the sealing hydrocarbon column height generally less than the traps amplitude, as well as early extension and interim tensile shearing and late reversal faults are adjustment faults. On the base of the analysis on trap style, the faults role of reservoir-forming and transporting system, fault controlling reservoir modes are divided into 2 types and 4 kinds in Hailar Basin. 2 types include primary and secondary reservoir and primary reservoir including three kinds: The first is oil and gas lateral migration in hydrocarbon kitchen margin and reverse fault sheltered reservoir-forming model, and reservoir-controlling fault is early extension and interim tensile shearing fault system; second model is oil and gas primary migration in the inside hydrocarbon kitchen and fault sheltered \"in the box\" reservoir-forming model; third is oil and gas lateral migration of uplifts within depression in the inside hydrocarbon kitchen, \"diffuse type\" reservoir-forming model. Both of models reservoir-controlling fault is the early extension fault. Secondary reservoir is the \"umbrella-shaped\" reservoir-forming model of oil and gas vertical migration along fault, the early extension and interim tensile shearing and late reversal fault system as reservoir-controlling fault.

基于“同一应力场不同边界条件形成不同性质断层”的构造解析原理，认为海拉尔盆地断陷期受南南东-北北西向拉张应力场作用，形成北北东和北东东向断裂，北北西向断裂明显走滑变形。断-坳转化期拉张应力场方位调整为近东西向，形成近南北向断裂，北北东、北东东和北北向断裂扭动变形。伊敏组沉积末期盆地回返，受近东西向挤压应力场控制盆地左旋压扭变形，北北东和北东东向断裂强烈反转。依据断裂变形特征叠加关系，海拉尔盆地形成四套断裂系统：早期伸展断裂、中期张扭断裂、早期伸展中期张扭断裂和早期伸展中期张扭晚期反转断裂。断陷构造层早期伸展中期张扭反向断裂形成断层遮挡圈闭，早期伸展断裂将凹中隆和斜坡切割破碎形成断层复杂化的背斜圈闭，早期伸展断裂与中期张扭断裂交叉组合，形成复杂的断块圈闭。断-坳构造层早期伸展中期张扭晚期反转断裂呈“梳状”组合，形成典型的断块圈闭。基于断裂活动时期与成藏期耦合关系以及典型油气藏解剖的结果认为，早期伸展和早期伸展中期张扭断裂在成藏关键时刻为遮挡断层，且封闭的烃柱高度一般均小于圈闭的幅度，早期伸展中期张扭晚期反转断裂为调整型断层。基于圈闭的样式、断层在成藏中的作用及输导体系分析，海拉尔盆地断裂控藏模式分为二型四类，二型为原生油藏和次生油藏，原生油藏包括三类：一是灶缘油气侧向运移反向断层遮挡成藏模式，控藏断裂为早期伸展中期张扭断裂系统；二是灶内油气初次运移断层遮挡“箱内”成藏模式；三是灶内凹中隆油气侧向运移“弥散式”成藏模式。这两种模式控藏断裂均为早期伸展断裂。次生油藏为油气沿断裂垂向运移“伞式”成藏模式，控藏断裂为早期伸展中期张扭晚期反转断裂系统。