【作者】 李军辉；

【导师】 卢双舫； 曹瑞成；

【作者基本信息】 东北石油大学 ， 矿产普查与勘探， 2010， 博士

【摘要】 呼和湖凹陷是海拉尔盆地的一个二级构造单元,近年来油气勘探揭示,呼和湖凹陷具有良好的勘探潜力,是海-塔盆地油气资源接替的新战场,目前呼和湖凹陷油气勘探越来越受到重视。本文立足于呼和湖凹陷油气勘探实践,在对盆地构造格架研究的基础上,通过建立研究区的层序地层格架,对层序结构和沉积体系分布及其演化进行系统研究,建立沉积砂体的分布和预测模式,同时结合油气成藏条件、勘探成果及所揭示的油气藏分布规律,建立油气成藏模式,预测油气勘探有利区带,对呼和湖凹陷下一步油气藏勘探具有一定的现实意义。同时对陆相断陷盆地层序地层学以及层序地层学应用于油气勘探等方面具有重要的理论意义。论文以层序地层学最新进展为理论基础,通过对全凹陷范围内的地震、钻井、测井、岩心以及古生物等资料的综合研究,依据层序界面特征,将呼和湖凹陷白垩系划分为3个一级层序、5个二级层序、8个三级层序,总结了该区层序界面的成因类型以及湖盆不同部位层序地层格架特征。在等时层序地层格架下,确定研究区主要发育冲积扇、扇三角洲、辫状河三角洲、湖底扇和湖泊沉积等5种沉积体系,并对典型砂体的特征进行了对比和分析,同时综合运用砂体、重矿物、古地貌以及地震前积反射特征等方面资料,从不同角度、不同层次对凹陷物源体系进行精细研究。系统研究了沉积体系的时空展布规律,建立了沉积演化模式,直观地再现沉积演变过程。系统分析了呼和湖凹陷构造特征及其构造演化。确定呼和湖凹陷经历了三期构造演化,由下而上分别为:早期伸展断陷期、中期裂后热沉降断-坳期和晚期坳陷期。纵向上主要发育了两套断裂系统,下部断裂系统展布方向主要是北东东向、北东向和北北东向。上部断裂系统展布方向主要为北北东向和北北西向。多期次构造运动控制着多种构造样式共存,这两套断裂系统的断裂性质及组合形态的不同,反映了其形成时应力性质存在明显的差别。研究表明,呼和湖凹陷同沉积断裂具有多种组合样式,包括平行断阶状、帚状、叉状、断层调节带等断裂体系,造就湖盆内复杂多变的构造古地貌及断裂坡折体系,严格控制着凹陷内砂体分散体系的沉积和堆积模式。揭示了同沉积断裂对沉积体系分布和砂体分散样式的控制作用,探讨了同沉积断裂坡折带控制的砂体与油气藏富集的关系。结合研究区的构造背景分析,将研究区分出断控陡坡带、缓坡断阶带、洼槽带3种典型构造单元,在此基础上分不同构造单元建了相应的层序构成样式和沉积体系域构成模式;这种特殊的层序构成样式也决定了不同的构造单元具有不同的油气成藏模式。在层序地层学分析的基础上,运用石油地质学理论对呼和湖凹陷油气成藏条件特征进行了研究,包括烃源岩特征、储层特征、生储盖组合特征、油气运移与聚集特征、圈闭特征和成藏过程有关的各个方面,分析了油气分布规律及富集的控制因素,建立了油气成藏模式,预测了西北缓坡带、南部洼槽带和东南陡坡带3个有利的油气勘探区带,确定了3个具体的勘探目标。更多还原

【Abstract】 Huhehu depression is a secondary structural unit in the Hailaer-Tamucage Basin, The recent exploration shows that, Huhehu depression has good exploration potential and it is a new substitute field for hydrocarbon resources in Hailaer-Tamucage Basin. Recently,the hydrocarbon exploration in Huhehu depression gets more and more attention.This article is stand on the petroleum exploration practice of Huhehu depression. Under the study of basin tectonic framework, through established the sequence stratigraphic framework of the study area, sequence structure and sedimentary system distribution and evolution were analyzed. distribution and prediction model of sedimentary sand bodies were built , also connected with hydrocarbon accumulation condition、exploration achievements and the hydrocarbon reservoirs distribution rule shows by it, the hydrocarbon accumulation model were built.that the hydrocarbon exploration favorable areas were predicted. This has some practical significance to the next hydrocarbon exploration of Huhehu depression,also has theoretical and production significance to continental fault basin sequence stratigraphyand sequence stratigraphy applied in hydrocarbon exploration and other filed.This article takes latest development of sequence stratigraphy as theoretical basis.On the comprehensive research of seismic、drilling、logging、cores and paleontology in the whole of depression, also based on the characteristics of sequence boundary,we could divided cretaceous of Huhehu depression into three first-order sequence、five second-order sequence and eight third-order sequence.We had summarized the genetic type of sequence boundary and sequence stratigraphic framework characteristics of lake basin’s different parts in this areas.On the base of isochronous stratigraphic framework,we had determined the study area main development five sedimentary systems,as alluvial fan、fan delta、braided river delta、sublacustrine fan、lake and so on,also had contrasted and analyzed the characteristics of typical sand body,and comprehensive application information of sandbody、heavy minerals、paleogeomorphic、seismic foreset reflection characteristics and so on,detailed study the deposit source of depression in different angles and different levels.We had system researched the space time distribution rule of sedimentary system,built the stabilized development model, intuitionistic reconstruction the process of sedimentary evolution.The characteristics and evolution of tectonic were analyzed in this article. Huhehu depression has three tectonic movements. From down to up separately is early extensional faulted depression stage, middle post-fault thermal subsidence fault sag stage, late depression stage. Two sets of fault system are developed in longitudinal direction: lower extensional faulted system mainly is NEE, NE and NNE; upper strike-slip fault system mainly is NNE and NNW. Multi-stages tectonic movement determines more structural style coexistent, the different fracture feature and combination form of this two fault system shows that the formation period’s stress characteristic had obvious differences.The results show that contemporaneous sedimentary faulting has many assemble pattern in Huhehu depression, contains parallel fault terrace type、broom type、forked type and fault accommodation zone ect fault system,this bring up complicated tectonic paleogeomorphic and slope-break system of lake basin,and the model of sedimentary and accumulation of sandbody dispersion system in the depression were strictly controlled by their. This revealed that contemporaneous sedimentary faulting had controlled the sedimentary system distribution and sandbody dispersion style,also discussed the relationship between sandbody controlled by codeposition faulted slope fold belt and hydrocarbon reservoir enrichment.On the base of structure background, Huhehu depression was decided into fault controlled steep slope zone, gentle slope fault terrace zone and depression zone. On this way, different tectonic units established different sequence architecture patterns and sedimentary system composing model. and this special types of sequence architecture patterns also decided that different tectonic units had oil-gas formation model.On the base of sequence stratigraphic analysis,we studied hydrocarbon accumulation condition characteristics of Huhehu depression by petroleum geology theory, contains source rock characteristics、reservoir characteristics、source reservoir cap assemblage characteristics、hydrocarbon migration and aggregation characteristics、trapping characteristics and other field in hydrocarbon accumulation process, analyzed the controlling factors of hydrocarbon distribution pattern and enrichment,built the hydrocarbon accumulation model. predicted three favorable hydrocarbon exploration zone: northwest gentle slope zone、southern depression zone and southeast steep slope zone.We had determined three concrete exploration target.更多还原