【作者】 曹强；

【导师】 叶加仁；

【作者基本信息】 中国地质大学 ， 油气田开发工程， 2010， 博士

【摘要】 伊通盆地是发育于郯庐断裂带东北段上的新生代走滑—伸展型断陷盆地,位于吉林省的长春市和吉林市之间,盆地西北侧隔大黑山地垒与松辽盆地相邻,东南侧为广阔的那丹哈达岭地体。盆地平面呈NE45°方向延伸的长条形,长160km,宽10-20km,总面积2200km2。本论文以伊通盆地油气成藏动力学为主要研究内容,在全面收集、整理、消化研究区现有地质、地球物理、地球化学、分析化验等资料与前人研究成果的基础上,以油气成藏动力学理论为指导,以伊通盆地构造沉积演化史为背景,采用静态与动态、宏观与微观、定性与定量相结合的综合研究技术,系统分析了伊通盆地的油气成藏的基本地质条件、流体动力场特征、油气成藏动力学过程,深入剖析了伊通盆地的输导体系、油气成藏主控因素与油气二次运移演化历史,最终划分与评价油气运聚单元。将为理解本区及类似走滑—伸展型断陷盆地油气成藏规律和预测伊通盆地有利勘探目标区提供借鉴。论文的主要研究内容和成果认识概括为以下4个方面：(一)伊通盆地油气成藏地质要素剖析1.基于伊通盆地各二级构造单元内烃源岩暗色泥岩分布、有机质丰度、类型及成熟度等方面的评价,揭示了伊通盆地发育始新统双阳组、奢岭组和永吉组三大烃源岩系,其中始新统双阳组暗色泥岩分布范围广,厚度大,源岩有机质丰度和成熟度相对较高,为盆地主力烃源岩系。2.通过分析伊通盆地始新统和渐新统储集层的主要沉积相类型、岩石学和物性特征等,指出储集岩以粉细砂岩和砂砾岩为主,储层物性虽随埋深增加逐渐变差,但鹿乡和莫里青断陷局部深度段发育的孔隙度和渗透率异常带可改善深部双阳组储集条件；储层的物性条件主要受沉积环境、成岩作用及构造运动等多种因素的联合影响；总体上,始新统双阳组储层储集条件最好,伊通盆地双阳组为盆地主要含油气层位。3.从盖层区域展布特征和盖层封闭机制两方面综合评价伊通盆地盖层封闭条件,发现伊通盆地四套区域性盖层中以永吉组泥质岩含量最高、且单层厚度大、区域上分布稳定,为本区最重要的盖层。本区超压封盖普遍发育,异常高压力(欠压实)的存在强化了泥岩的封盖作用；基于上述成藏地质要素综合评价,指出伊通盆地最重要的生储组合是以双阳组为主要储层的自生自储类型。(二)伊通盆地流体动力场分布特征及演化历史研究1.通过统计盆地不同部位现今地温梯度和热流值,指出现今地温梯度纵向上浅部地温梯度高于深部；横向上,莫里青断陷和鹿乡断陷的地温梯度较高,岔路河断陷相对较低,且同一断陷不同三级构造单元内,表现为凹陷地温梯度要低于断阶带和凸起的规律；深部断裂的分布及其导热作用对现今地温场的横向分布有很大影响。应用盆地模拟技术反演了各二级构造带代表井的古温度场的演化,结果表明古地温梯度高于现今地温梯度。2.通过统计盆地储层和泥岩盖层的实测地层压力数据,发现伊通盆地储层多为常压,超压点主要集中于岔路河断陷和莫里青断陷始新统双阳组内；伊通盆地浅部泥岩表现为正常压实—压力,而地下深处泥岩则一般具有异常压实—压力特征,泥岩欠压实段主要分布于始新统地层中,发现伊通盆地有三种储盖能量配置类型。基于盆地模拟技术恢复了伊通盆地5口单井和13条测线的古超压演化历史,研究发现剖面上古超压集中分布于始新统下部奢岭组和双阳组地层内；单井和剖面剩余压力都具有“积累—释放”演化特征,盆地演化早期以欠压实为主导增压作用,中晚期则以生烃增压为主；构造抬升剥蚀为主要泄压机制。3.基于上述13条剖面古压力恢复,结合充注史研究成果对伊通盆地剖面流体势演化特征进行剖析,结果显示盆地现今流体势分布以“重力流特征”为主,区域上生烃凹陷处双阳组地层为流体势高值区；古流体势演化以近西北缘生烃凹陷始新统地层为持续的高势区,沿基底和断层向南东方向的断阶带和隆起区流体势逐渐降低,表明伊通盆地的流体大规模横向运移主要发生始新统双阳组地层内,而在其上部,油气纵向运移主要依靠断层的垂向输导；同一输导层内的流体总体上由凹陷向斜坡高部位运移,高部位是油气运移的区域指向带；油气主成藏期的始新统双阳组地层流体势值普遍较高,且岔路河断陷深凹处双阳组地层流体势显著高于莫里青和鹿乡断陷；古流体势的发育过程受控于古超压的演化,由古至今同样具有旋回性、波动性和减弱性。(三)伊通盆地油气成藏动力学过程分析1.基于伊通盆地岔路河组底面不整合面以下齐家组和万昌组地层剥蚀厚度(单井)进行恢复结果,通过对伊通盆地10口代表性单井的地层埋藏史模拟重建,发现伊通盆地在其构造-沉积发展历史上表现出多幕演化特征。总体上,盆地演化早期的的沉积和构造沉降速率高于晚期：不同构造单元沉积—沉降特征表现为自古至今差异性逐渐变小。2.采用瞬变热流模型(Transit Heat Flow)恢复伊通盆地10口代表性单井的地热演化史,结果表明伊通盆地地层升温速率明显受沉积速率的制约,且两者间呈正比关系。盆地由古至今沉积速率和升温速率都不断减小,与盆地构造演化相一致。3.在准确恢复热史的基础上,选用LLNL-Easy%Ro模型来恢复烃类的成熟演化史,结果表明,始新统烃源岩在岔路河断陷热演化程度高于鹿乡断陷和莫里青断陷；其中,始新统双阳组主力烃源岩进入生烃门限较早,现今热演化程度高,多已进入大量生油阶段(Ro=1.0-1.3%),在岔路河断陷内多部分进入高成熟—过成熟阶段；始新统奢岭组烃源岩热演化程度虽小于双阳组,但目前多数地区仍处于大量生油阶段,在岔路河断陷内已进入湿气生成阶段(Ro=1.3-2.0%)。始新统永吉组烃源岩仅在岔路河断陷刚刚进入生油门限。4.本次各断陷代表单井主要烃源岩层生烃史模拟采用化学动力学模型,模拟结果表明,始新统双阳组烃源岩的生烃强度最高,奢岭组烃源岩生烃能力次之,永吉组生烃能力微弱；岔路河断陷生气强度均大于生油强度,双阳组和奢岭组烃源岩热演化程度高,产物以气态烃为主。相反地,莫里青断陷和鹿乡断陷烃源岩热演化程度中等,产物以液态烃为主。排烃史模拟结果表现为始新统双阳组的排气和排油强度最大,为伊通盆地的主要排烃层位；岔路河断陷内烃源岩排气强度大于排油强度,产物气态烃为主,鹿乡断陷和莫里青断陷内则以液态烃为主要产物；始新统双阳组源岩开始排烃的时间早于奢领组烃源岩,多在渐新世中期及之前；双阳组烃源岩的排烃效率最大,其排油效率和排气效率多大于50%。5.通过对伊通盆地岔路河断陷和鹿乡断陷磷灰石裂变径迹年代学研究表明,自渐新世以来岔路河断陷至少经历了两期构造事件(抬升冷却),分别对应于渐新统万昌组沉积末期和岔路河组沉积末期发育的两期构造抬升事件；自渐新世以来鹿乡断陷至少经历了一期隆升事件,对应于渐新统万昌组沉积末期开始的构造隆升事件。6.基于含油气包裹体资料探讨伊通盆地油气充注史发现,伊通盆地岔路河断陷发育三期油气成藏,集中于始新统双阳组和奢岭组。鹿乡断陷和莫里青断陷皆发育两期油气成藏,集中于双阳组。(四)伊通盆地油气运聚单元划分及评价1.油气特征及来源研究表明伊通盆地不同断陷的油气具有不同特征和来源。岔路河断陷以产气为主,原油以轻质原油为主,都来自于始新统双阳组烃源岩；莫里青和鹿乡断陷主要产油,原油以轻质原油和正常原油为主,主要来自始新统双阳组烃源岩。2.伊通盆地输导体系主要包括砂体、断层以及基岩不整合面；不同二级构造单元的有不同的输导体系配置,导致其运移特点明显不同。其中莫里青断陷断裂不发育,油气运移以侧向为主；岔路河断陷纵向油气分布范围广,指示本区发育较强烈的垂向输导作用；鹿乡断陷输导体系最为发育且配置良好,侧向和垂向运移共同输导双侧生烃凹陷生成的油气向五星构造带汇聚成藏,形成伊通盆地目前最大规模油气藏—长春油田。3.控制伊通盆地油气成藏的主要因素有断裂、基岩不整合、砂岩储层、盖层和温压系统；在不同地区这些因素的影响作用不同,导致了不同的油气成藏模式。4.本次应用Basin Mod软件系统中Basin Flow和Basin View模块,模拟恢复伊通盆地E2s—>E2s生储系统油气二次运移演化,结果表明,主成藏期时流体运移最为活跃,此阶段生烃凹陷油气供给充分,运移流线密度大,运移范围广、作用强烈,位于生烃凹陷中心周围的各种岩性、构造及复合圈闭具有最为优越的油气运聚条件。5.根据油气运聚的分割槽原理,基于盆地主力生储系统(成藏组合)E2s—>E2s油气主成藏期的油气运移流线图(10Ma),伊通盆地在平面上共可划分为11个油气运聚单元,伊通盆地的油气运聚条件以莫里青断陷运聚单元Ⅰ、鹿乡断陷运聚单元Ⅰ和岔路河断陷运聚单元Ⅱ为最为优越。这些运聚单元内发育生烃富凹,油源条件充足；始新统双阳组优质砂体广泛分布,储集条件优越；断裂-砂体-基岩不整合复合输导体系发育,沟通油气不断汇聚至有利圈闭成藏；加之晚期断裂不甚发育,联合区域优质泥岩盖层封闭下部双阳组的油气,油气保存条件良好。更多还原

【Abstract】 Yitong Basin is a Cenozoic slip-extensional rift basin that developed in in northeast section of the Tanlu Fault zone, and is located between the Changchun city and Jilin city of Jilin province.With the Daheishan horst, which adjacent by the Soliao basin, on the northwest edge of the Yitong basin and the Nadanhadaling terra on the southeast edge, the basin’s form looks like a long belt with a length of 160km, width of 10-20km and the total area of 2200km2, and extend for the direction of NE45.Based on generally collecting, arranging and studying the present documents in geology, geophysics, geochemistry and analytical experiments and the previous achievements of the research area, guided by the theory of petroleum pool forming dynamics, applying the integrated technique that combining the static with the dynamic, the macroscopic with the microscopic and the qualitative with the quantitative, with the primary content about the dynamics of hydrocarbon accumulation in the Yitong basin, the fundamental reservoir forming conditions, the feature of the fluid dynamic field and the process of the dynamics of hydrocarbon accumulation in the Yitong Basin were systematically analyzed. And the carrier system, the main controlling factors of hydrocarbon accumulation and the evolution history of secondary migration of hydrocarbon in the Yitong Basin were deeply dissected and finally the migration and accumulation units of hydrocarbon were classified and evaluated. It will help to better understand the rules for the hydrocarbon accumulation in the Yitong Basin and the similar slip-extensional rift basin, and provide an example for predicting the favourable exploration targets. The thesis is divided into four parts as follows.1. Analysis on the geological elements of hydrocarbon accumulation in the Yitong BasinBased on the thickness of dark shale, organic matter abundance, organic matter type and organic matter maturity, the source rocks of secondary tectonic units in the Yitong Basin were comprehensively evaluated. The results indicate that there are three types of source rock named as the Eocene Shuangyang, Sheling and Yongji formations, and the Eocene Shuangyang is supposed to be the major source rock due to the wide distribution and great thickness of the dark shale, relatively richer organic matter abundance and higher maturity.Based on the analysis of the the sedimentary facies, lithological and physical properties of the Eocene and Oligocene reservoirs in the Yitong Basin, the results suggest that the siltstones, fine sandstones and sandy conglomerates are the major reservoir rocks. Although the physical properties of the reservoirs are gradually destroyed due to the increase of burial depth, the reservoir conditions of Shuangyang Formation in deep depth may be improved by possible development of the abnormal porosity and permeability in partial intervals in the Luxiang fault depression and the Moliqing fault depression. Reservoir conditions were mainly controlled by multiple factors such as sedimentary environment, diagenesis and tectonic movements. In a word, with the most favorable reservoir conditions, the Eocene Shuangyang formation is the major oil bearing interval in the Yitong Basin.The sealing conditions of cap rocks were intregratelly evaluated on two aspects:regional distribution characteristcs and seal mechanism of cap rocks, which indicates that the Yongji formation is the most important cap rock in theYitong Basin due to its highest shale content, greatest single thickness and stable regional distribution. Excess pressure generally exsits in cap rocks from the study area, therefore, the sealing condition is improved by abnormal high pressure (undercompacted) in the shale. Based on the comprehensive evaluation of the above geological elements of hydrocarbon accumulation, it can be concluded that the type of authigenic reservoir is the most important one in the Yitong Basin.2. The distribution characterictics and evolution history for the fluid dynamic fieldBased on the statistics of the geothermal gradient and heat flow at present all around the basin, it indicates that the average geothermal gradient within the shallow layers is higher than the deep ones. Laterally, the average geothermal gradient is relatively higher within the Moliqing fault depression and Luxiang fault depression but relatively lower within the Chaluhe fault depression. Within the different tertiary tectonic units in the same fault depression, the sag always has higher geothermal gradient than the structural high. The distribution and thermal conductivity of the major faults plays an important role on the lateral distribution of geothermal field at present. By using the technique of BasinMod, the evolution history of the geothermal field was rebuilt based on the representative wells from the different secondary tectonic units, the results suggested that the geothermal gradient gradually went down in the evolution history.By caculating the measured formation pressure data within the reservoirs and cap rocks, it can be concluded that the reservoir geopressure is mostly normal in the Yitong Basin, and the overpressure mainly develop within the Shuangyang famation of the Chaluhe and Moliqing fault depressions. The deep shales usually have the overpressure while the shallow shales show the normal compaction trend. The uncompacted zone in the shale is mostly distributed in the Eocene formation, and there are three types of reservoir-seal energy assemblage in the Yitong basin. By using the technique of BasinMod, the evolution history of the excess pressure was rebuilt based on 5 wells and 13 lines, the results indicated that the excess pressure was mainly distributed within the Eocene Sheling and Shuangyang formations. The 1D and 2D modeling results both showed that the formation pressure evolution in the study area has obviously undegone cycles of accumulation and expulsion, the mechanism for pressure accumulation was undercompaction in the early period but hydrocarbon generation in the late period. The tectonic uplift was the main mechanism for pressure release.Base on the modeling of excess pressure evolution history for the above 13 2D lines, combined with filling history, the evolution chatacteristics of fluid potential was analyzed in the Yitong basin. The results indicated that the current distribution of fluid potential is characterized by "gravity flow" feature, and the high-value area of fluid potential is within the Shuangyang formation of the hydrocarbon generation kichen. The evolution history of fluid potential can be featured by the continuing developing high fluid potential within the Eocene formations in northwest of the hydrocarbon generation kichen, the fluid potential gradually decreased along the basement and fault towards the uplift in the Southeast area, which suggested that the large-scale lateral migration mainly happened within the Shuangyang Formation. And the fault should be the major vertical pathway for hydrocarbon migration. As a whole, the hydrocarbon migration always happened in at the same transport layer from the depression to slope high, and the structural high should be the favorable area for hydrcarbon migration during all the stages. In the critical period for the hydrocarbon accumulation, the fluid potential is relatively higher within the Shuangyang Formation, and the hydrocarbon generation kichen within the Chaluhe fault depression had a remarkable higher fluid potential than the depression within the Luxiang and Moliqing fault depression. Futhermore, the development of paleo-fluid potential was controlled by the evolution of palaeo-overpressure, both of them have cycling, Volating and decreasing trend.3. The study on the dynamics of hydrocarbon accumulation in the Yitong BasinBased on the results of erosion thickness restoration for the Qijia and Wanchang formations in the Yitong Basin, the burial history of 10 wells was rebuilt and the modeling results indicated that the tectonic-sedimentation development in the Yitong Basin was characterized by multiphasic evolution. Generally, the Yitong Basin had a higher sedimentation rate and tectonic subsidence rate in early period compared with the late period. The tectonic-sedimentation development in different tectonic units gradually became more and more similar.Based on the model of transit heat flow, the geothermal evolution history was rebuilt based on the 10 representative single wells in the Yitong Basin, the result showed that formation temperature rate was obviously controlled by sedimentation rate and they have proportional relationship. The basin sedimentation rate and formation temperature rate both decreased in the geological period, which are correspondent to the structural evolution of the Yitong Basin.In this study, chemical kinetics model was used for hydrocarbon generation history modeling of the main hydrocarbon source rocks of each representative single well in fault depression. Simulation results showed that, source rocks of Shuangyang Formation had the highest hydrocarbon-generating intensity, Sheling Formation took the second place, Yongji Formation had weak hydrocarbon generation capacity. Generation intensity of gas in Chaluhe fault depression was higher than oil, hydrocarbon source rocks of Shuangyang Formation and Sheling Formation had high thermal evolution degree, while product was dominated by gaseous hydrocarbon. Conversely, Moliqing fault depression and Luxiang fault depression had moderate thermal evolution degree, with liquid hydrocarbon as the main product. The simulation result of hydrocarbon expulsion history was consistent with hydrocarbon generation history and manifested as Shuangyang Formation had the highest gas expulsion intensity and oil expulsion intensity, which was the major hydrocarbon expulsion horizon. gas expulsion intensity of source rocks was higher than oil expulsion intensity in Chaluhe Fault Depression, while product was dominated by gaseous hydrocarbon, while Luxiang Fault Depression and Moliqing Fault Depression took liquid hydrocarbon as the main product. the source rocks of Shuangyang Formation began to expell hydrocarbon ealier than Sheling Formation, mostly in middle Oligocene. the source rocks of Shuangyang Formation had the highest hydrocarbon expulsion efficiency, the oil expulsion efficiency and gas expulsion efficiency was mostly larger than fifty percent.The results of the apatite fission-track chronology for the Chaluhe Fault-Depression and Luxiang Fault Depression in the Yitong Basin showed that Chaluhe Fault Depression had experienced two stages of tectonic movement (uplift-cooling) since the Oligocene, respectively corresponding to the tectonic uplift event at the sedimentary end of Wanchang Formation and that of Chaluhe Formation. Luxiang Fault Depression had experienced at least one stage of tectonic uplift event since Oligocene, corresponding to the tectonic uplift event at the sedimentary end of Wanchang Formation.Study on hydrocarbon filling history of the Yitong Basin based on oil and gas bearing inclusion showed, Chaluhe Fault Depression in the Yitong Basin developed three stages of hydrocarbon accumulation, and mostly concentrated in Shuangyang Formation and Sheling Formation. Moliqing fault depression and Luxiang fault depression both had two stages of hydrocarbon accumulation, which mostly developed in the Shuangyang Formation.4. The classification and evaluation for the migration and accumulation units of hydrocarbonCharacteristics of hydrocarbons and oil-source correlation has been analyzed in the study, the results suggested that hydrocarbons in different secondary tectonic units have different characteristics and origin. The natural gas is the main product within the Chaluhe fault depression, whose oil is dominated by light crude oil. The oil and natural gas both originated from the source rock of the Eocene Shuangyang Formation. By contrast, the oil is the main product within the Moliqing and Luxiang fault depressions. The oil mainly originated from the source rock of the Eocene Shuangyang Formation as well and was dominated by light and normal crude oil.The hydrocarbon carrier system within the Yitong Basin mainly includes sand body, fault and basement unconformity, and different secondary tectonic units have its unique configurations of hydrocarbon carrier system, which result in obvious different migration styles. Because of the lack of faults within the Moliqing fault depression, this area is dominated by lateral hydrocarbon migration. By contrast, the hydrocarbon is vertically wide distributed within the Chaluhe fault depression, indicating that vertical hydrocarbon migration intensively developed in this area. The Luxiang fault depression has the most developed hydrocarbon carrier system and favorable configuration, therefore, the oils from the two hydrocarbon-generation kitchens could continuously accumulated towards the traps within the Wuxing structural high through the lateral and vertical hydrocarbon carrier system. Finally the biggest hydrocarbon reservoir formed as Changchun Oil Field in the Yitong Basin.The main controlling factors for hydrocarbon accumulation within the Yitong Basin are fault, basement unconformity, sandstone reservoir, seal and temperature-pressure system. These characters have different influential actions in different areas, which lead to different hydrocarbon accumulation patterns.In this study, the module of BasinFlow and Basin View was used as a simulator for recovering the evolution of hydrocarbon secondary migration within the E2S—>E2S source-reservoir system in the Yitong Basin, it can be concluded that The hydrocarbon secondary migration became the most intensive during the main period of oil and gas accumulation and in this phase oil and gas was sufficiently provided by hydrocarbon-generation kitchen, the hydrocarbon secondary migration can be characterized by the big density of flow line, the wide distribution of hydrocarbon migration and the strong affect of hydrocarbon migration. Therefore, the wide distributed lithologic, structural and complex traps, which are located within or nearby the hydrocarbon-generation kitchen, will be the most favorable targets for hydrocarbon migration and accumulation in the Yitong Basin.According to the concept for dividing trough of hydrocarbon migration and the source-reservoir system (E2S—>E2S) of the flow chart during the main period of oil and gas accumulation (10Ma), the Yitong Basin can be divided into 11 hydrocarbon migration-accumulation units. and the best units are the hydrocarbon migration-accumulation unitⅠin the Moliqing fault depression, the hydrocarbon migration-accumulation unitⅠin the Luxiang fault depression and the hydrocarbon migration-accumulation unitⅡin the Chaluhe fault depression. These hydrocarbon migration-accumulation units have some common features:the favorable hydrocarbon-generating kitchens were developed and sufficient oil source was supplied, the high-quality sand body in the Shuangyang Formation was highly developed and good reservoir condition was provided, the favorable complex conduit system of fault-sand body-basement unconformity were developed within these areas. Besides, the lack of tensing faults in the late period, the good sealing condition was provided, so the preservation condition for hydrocarbon is perfect.更多还原