Discovery of Hesigewula Sag on the western margin of Da Hinggan Mountains in China and its significance in petroleum geology

With Songliao Basin in northeast China entering the middle-late stage of the exploration and development of oil and gas resources, it is urgent to open up new areas for oil and gas exploration on the periphery of the basin. Five sedimentary sags have been discovered in the western margin of the Da Hinggan Mountains through high-precision gravity, magnetic, and electrical prospecting engineering. According to the conditions of the 5 sags such as buried depth, area, and the scale of source rock, Hesigewula Sag was preferentially selected to deploy two-dimensional seismic prospecting and drilling. As a result, the stratigraphic distribution and structure of Hesigewula Sag were preliminarily ascertained, the main sedimentary facies developed in Aershan Formation-Tengger Formation of the Lower Cretaceous was summarized, and the assessment parameters of source rock of Hesigewula Sag were obtained. According to the research results, the Hesigewula Sag can be divided into 3 second-order tectonic units including the western bulge, the central sag, and the eastern bulge respectively, and the sag was formed mainly subject to the west fractures. Three sedimentary facies including fan delta facies, braided river delta facies, and lacustrine facies have been identified in the Aershan Formation-Tengger Formation of the sag. The source rock in the first member and second member of Tengger Formation in the sag features high abundance of organic matter, meeting the standards of good source rocks. The kerogen of the source rock is mainly of type II₁ – II₂. The organic matter in the source rock is characterized by low maturity and it entered the evolution stage of low maturity from the second member of Tengger Formation. Furthermore, Hesigewula Sag bears a strong similarity to other petroliferous sags in Erlian Basin in structure, sedimentation, source rock, and other characteristics. Therefore, it can be preliminarily determined that Hesigewula Sag boasts great potential for oil and gas resources.     

苏北盆地盐城凹陷兴桥1井烃源岩特征及气源分析

盐城凹陷兴桥1井钻遇二叠系孤峰组和栖霞组两套烃源岩。孤峰组为暗色泥岩,视厚度11.3m,有机碳最高为1.44%,平均0.74%,有机质类型偏向Ⅲ型;栖霞组为暗色碳酸盐岩,厚度较大,其中TOC>0.4%的地层的折算厚度大于42m,有机质类型主要为Ⅱ2型。这两套烃源岩的有机质热演化程度较低,至今仍具一定的生烃能力。兴桥1井上白垩统浦口组及下二叠统栖霞组见到多层气显示,浦口组的气源可能为深部二叠系,栖霞组的气体则可能受到更深部寒武系气源的侵入。     

基于古地貌和源-汇特征分析的烃源岩评价:以珠江口盆地阳江凹陷为例

近海盆地烃源岩评价是海上油气勘探成败的关键,也是亟待解决的关键科学问题。珠江口盆地阳江凹陷近期实现了油气勘探的重大突破,并展示了该区广阔的勘探前景。但在海上探井井位不足的情况下,仅靠地震资料难以客观地评价烃源岩的生烃潜力。为了进一步明确该区主要生烃层文昌组的生烃潜力,本文首先利用最新的四维层序地层模拟(Bandlands软件)技术,恢复了阳江凹陷古近系沉积期间的古地貌。古地貌恢复预测的古环境特征较好地揭示了文昌组古地貌与沉积体系的对应关系,说明文昌组古地貌背景对烃源岩沉积发育的影响较大。结合沉积体系的研究结果,分析总结了该区文昌组沉积时的源-汇特征,表明该凹陷文昌组早期是烃源岩发育的最有利时期。再结合洼陷古地貌特征、烃源岩的发育程度(主要依据半深湖相的厚度和面积)、与油源断裂的沟通及浅部圈闭的匹配等将各洼陷烃源岩综合划分为优质烃源岩、较好烃源岩和一般烃源岩3个级别:恩平20洼、恩平21洼为优质烃源岩;恩平27洼为较好烃源岩;恩平19洼、阳江24洼等为一般烃源岩。在对烃源岩分布预测的基础上,根据已钻井烃源岩样品的分析化验资料,将实验分析、地质分析与模拟结果相结合,分别对文昌组上段和文昌组下段两套烃源岩的沉积埋藏史、热演化史及生烃史进行综合分析。最后利用Petromod盆地模拟技术模拟了文昌组烃源岩的生烃潜力。模拟结果表明:恩平20、21洼和恩平27洼文昌组下段烃源岩生烃强度大于文昌组上段烃源岩生烃强度,说明文昌组下段烃源岩为生烃潜力最好的层段,且凹陷中东部的恩平20、21洼和南部的恩平27洼为生烃潜力最好的洼陷,具有较好的勘探潜力。这种基于古地貌和源-汇特征分析的烃源岩评价,对近海油气勘探具有重要的指导作用。     

准噶尔盆地四棵树凹陷烃源岩地球化学特征及其对车排子凸起油气聚集的贡献

准噶尔盆地西南缘四棵树凹陷主要分布侏罗系、白垩系和古近系3套潜在烃源岩,其中侏罗系八道湾组烃源岩有机质丰度较高,有机质类型以Ⅲ型为主,部分为Ⅱ2型,生烃潜力较高;三工河组烃源岩有机质丰度、类型明显偏差,生烃潜力较低;西山窑组泥岩有机质丰度较高,但由于受西山窑组沉积末期构造抬升导致地层剥蚀的影响,烃源岩厚度较小,总体上生烃条件较差;白垩系烃源岩在四棵树凹陷最大厚度可达300 m,处于低熟阶段,生烃潜力较小;古近系烃源岩有机质丰度较高、类型好,但成熟度偏低,生烃条件较差。侏罗系八道湾组烃源岩处于主要生油阶段;白垩系烃源岩已达到生烃门限,处于低熟—中等成熟阶段;古近系烃源岩成熟度偏低,目前仍处于未熟到低熟阶段。油源对比表明,四棵树凹陷北部斜坡及车排子凸起带原油主要来源于四棵树凹陷及沙湾凹陷侏罗系烃源灶,后期受到白垩系低熟油源灶的侵染,古近系烃源岩的油源贡献有限。     

Modeling of gas generation from the Alam El-Bueib formation in the Shoushan Basin, northern Western Desert of Egypt

The Shoushan Basin is an important hydrocarbon province in the northern Western Desert, Egypt, but the burial/thermal histories for most of the source rocks in the basin have not been assigned yet. In this study, subsurface samples from selected wells were collected to characterize the source rocks of Alam El-Bueib Formation and to study thermal history in the Shoushan Basin. The Lower Cretaceous Alam El-Bueib Formation is widespread in the Shoushan Basin, which is composed mainly of shales and sandstones with minor carbonate rocks deposited in a marine environment. The gas generative potential of the Lower Cretaceous Alam El-Bueib Formation in the Shoushan Basin was evaluated by Rock–Eval pyrolysis. Most samples contain sufficient type III organic matter to be considered gas prone. Vitrinite reflectance was measured at eight stratigraphic levels (Jurassic–Cretaceous). Vitrinite reflectance profiles show a general increase of vitrinite reflectance with depth. Vitrinite reflectance values of Alam El-Bueib Formation range between 0.70 and 0.87 VRr %, indicating a thermal maturity level sufficient for hydrocarbon generation. Thermal maturity and burial histories models predict that the Alam El-Bueib source rock entered the mid-mature stage for hydrocarbon generation in the Tertiary. These models indicate that the onset of gas generation from the Alam El-Bueib source rock began in the Paleocene (60 Ma), and the maximum volume of gas generation occurred during the Pliocene (3–2 Ma).     

渤海盆地辽东湾地区古近系烃源岩成熟演化模拟

古近系是辽东湾地区的主力烃源岩层系, 包括孔店组(Ek)-沙河街组四段(Es⁴)、沙河街组三段(Es³)、沙河街组一、二段(Es1-2)、东营组三段(Ed³)4套烃源岩, 它们主要分布在该地区的3个凹陷(辽西、辽中和辽东)的各个次洼中。在沉积和构造发育史的基础上, 结合烃源岩地球化学和热史等参数对烃源岩成熟演化进行模拟。对辽中凹陷各洼陷典型井区的烃源岩演化模拟表明辽中凹陷不同洼陷内各烃源岩层系的成熟演化历史存在明显差异:在东营组沉积末期,Es⁴-Ek烃源岩普遍进入生油门限,现今,基本上处于高-过成熟阶段;在馆陶组沉积末期,Es³和Es^-2烃源岩普遍进入生油门限,Ed³烃源岩部分进入生油门限,现今,Es³和Es^-2烃源岩在辽中凹陷的部分地区达到生油高峰期。同时, 利用Basinview软件模拟了辽东湾地区古近系4套烃源岩的成熟演化历史, 表明在盆地演化过程中同一套烃源岩在辽东湾地区不同凹陷进入生油门限和达到生油高峰及生气阶段的时间存在差异。研究成果可以为该地区深凹区的烃源岩预测与评价和计算烃源岩体积、生、排烃量等提供重要参数,这对指导该地区的油气资源勘探具有重要意义。      

澳大利亚波拿巴盆地侏罗系烃源岩热史及成熟史模拟

澳大利亚波拿巴盆地侏罗系海陆过渡相烃源岩热史及成熟史研究对波拿巴盆地浅水油气勘探具有指导意义.在恢复波拿巴盆地北部地史和热史的基础上,利用EASY％Ro模型计算了波拿巴盆地下—中侏罗统(Plover组泥岩)和中—上侏罗统(Elang组泥岩和Frigate组页岩)两套烃源岩的成熟史,并分别对比了下—中侏罗统和中—上侏罗统...     

内蒙古银额盆地查干凹陷烃源岩生烃和排烃史研究

为深入研究银额盆地查干凹陷油气的成藏过程 ,优化勘探目标的选择 ,在分析烃源岩特征的基础上 ,应用动态数值模拟技术 ,定量恢复了研究区主要烃源岩层系的生烃、排烃历史。研究表明 ,查干凹陷主要发育 3套烃源岩系 ,其中下白垩统巴音戈壁组二段泥岩为主力烃源岩 ,具较高的有机质丰度、生烃强度与排烃效率 ;烃类排出具阶段性、多期次幕式排烃的特点。以巴音戈壁组二段为源岩的油气系统应是本区油气勘探的主要目标     

吐哈盆地西南部铀矿化特征与成矿潜力评价

吐哈盆地西南部艾丁湖斜坡带为一相对稳定的地质构造单元,其上在温湿气候条件下超覆沉积了下侏罗统八道湾组、三工河组和中侏罗统西山窑组。中侏罗统西山窑组主体为一套河流相-河流三角洲相的含煤碎屑岩系;地层泥-砂-泥结构发育良好,砂体岩性主要为成分成熟度和结构成熟度均较低的长石质砂(砾)岩、岩屑砂(砾)岩;岩石为黑色和灰色原生地球化学,具有较强的还原能力。组内层间氧化带广泛发育,总体可划分为完全氧化亚带、其不完全氧化亚带、氧化还原过渡带和原生岩石带,砂岩型铀矿化完全受层间氧化带控制,位于氧化还原过渡带内。目前已在区内找到了十红滩大型层间氧化带砂岩型铀矿床。通过对吐哈盆地西南部构造地质背景、找矿目的层、层间氧化带、水文地质条件、岩石原生地球化学类型及区内已发现铀矿床基本特征的综合分析,指出区内未来仍具有广阔的层间氧化带型铀矿找矿前景。认为十红滩地区作为下一步铀矿勘探基地,主攻层位为中侏罗统西山窑组第一、三岩性段;迪坎儿地段为下一步普查远景区,主攻层位为西山窑组第三岩性段;白咀山、八仙口地段为下一步预查远景区,主攻层位为西山窑组第二、三岩性段。     

珠江口盆地阳江凹陷油气重大发现与成藏启示

珠江口盆地阳江凹陷近两年先后发现了多个中型油田和含油构造,短短两年时间里从一个沉寂了近四十年的勘探新区成为珠江口盆地(东部)的热点探区.主力含油层段韩江组下段和珠江组上段储层物性良好,以中高孔、中高渗储层为主,油气产量高.这些油田的发现对珠江口盆地的新区勘探具有重要借鉴意义.①良好的烃源发育背景是新区突破的前提:阳江凹...     

伊犁盆地洪海沟地区中侏罗统西山窑组上段沉积特征及其与铀成矿的关系

研究伊犁盆地南缘洪海沟地区主力含铀层系--中侏罗统西山窑组上段的沉积特征,为该区下一步铀矿地质勘查提供理论依据。根据沉积结构、岩性组合、沉积韵律、沉积构造、测井曲线等特征,认为西山窑组上段在洪海沟地区主要发育曲流河沉积。根据连井剖面特征,以及砂体厚度、砂地比等沉积特征在平面上的变化,洪海沟地区西山窑组上段沉积相的平面分布规律明显,中间为沿北西-南东向展布的曲流河道,河道南部为河漫沼泽,北部为河漫滩。综合研究区岩性、构造、铀源等成矿条件,西山窑组上段赋存的铀矿体主要受河道砂体展布方向、河道砂体厚度、砂体粒度、砂体中的泥岩夹层、地层产状等因素控制。     

渤海湾盆地南堡凹陷油气运移路径模拟及示踪

在油气成藏期分析的基础上, 采用盆地流线模拟技术对渤海湾盆地南堡凹陷成藏关键时刻油气运移过程进行了恢复, 根据原油含氮化合物和成熟度指标对典型油气富集区的油气运移路径进行了示踪.油气运移路径模拟结果表明, 研究区南部凹槽源内和源下油气藏在东营末期(距今24.6 Ma)有一期较小规模运移, 油气大规模运移时期为明化镇中期(距今9 Ma).南部凹槽源上油气藏和北部凹槽源内油气藏在明化镇中期有少量油气运移, 大规模运移时期为明化镇末期(距今2 Ma).目前南部凹槽勘探程度较低, 模拟结果表明其具有较大的勘探潜力.原油地球化学指标揭示在源上油气藏富集区, 对于伸入洼陷中心的油源断层, 油气主要沿断层走向, 向构造高部位及断层面两侧砂体运移; 对于平行洼陷中心的油源断层, 油气主要沿断层倾向向构造高部位运移.在源内油气藏富集区, 油气主要通过有效烃源岩层系内发育的砂体向构造高部位运移.      

琼东南深水区华光凹陷海陆过渡相烃源岩早期预测

深水低勘探领域是当今世界油气勘探关注的热点之一,有效烃源岩发育程度是低勘探领域烃源岩早期评价首先需要回答的关键问题。而低勘探领域钻井稀少,缺乏采样分析资料,严重制约着烃源岩早期预测。针对这一严峻挑战,本文在借鉴邻区井孔实测资料的基础上,充分利用层序地层学、有机地球化学和地球物理技术,探讨了以多项烃源岩参数为主的5项烃源岩早期预测评价方法,即（1）利用层序地层分析方法确定有利烃源岩发育层段;（2）利用地震速度-岩性定量预测方法确定烃源岩厚度;（3）利用地震绝对速度定量估算烃源岩成熟度Ro;（4）运用地震相转沉积相,再由沉积相转有机相方法预测烃源岩有机相类型和分布;（5）烃源岩层段综合评价优选。应用该方法对华光凹陷海陆过渡相烃源岩进行了烃源岩早期预测,发现崖城组各段烃源岩厚度具有北厚南薄的特征,崖二段烃源岩最厚可达450m;崖城组烃源岩热演化程度整体较高,受埋深影响,崖三段烃源岩Ro值最高;崖二段浅海相烃源岩分布范围最大,滨岸平原沼泽相最窄,崖一段和崖三段浅海相烃源岩分布范围小,但滨岸平原沼泽相烃源岩分布最宽,并且扇三角洲分流平原沼泽相烃源岩分布较广;烃源岩综合评价分析认为崖二段是最有利烃源岩,崖一段和崖三段是较有利烃源岩。     

Petroleum accumulation conditions of the Paleogene Shahejie formation in Qingdong Sag of Bohai Bay Basin,Eastern China

Qingdong Sag is a potential area for oil and gas exploration in Bohai Bay Basin of Northern China. In order to find a direction for the subsequent exploration of Jiyang Depression, oil and gas accumulation conditions of Qingdong Sag are studied in details by using geochemistry, sequence stratigraphy, sedimentology, and petroleum geology methods, integrated with geological, seismic, and testing data. The results show that the Shahejie Formation in the Qingdong Sag was mainly deposited in deltaic and lacustrine settings. The upper part of member 4 of the Shahejie Formation formed in delta, beach bar, low stand fan, and submarine fan. Three tectonic settings (extensional, strike-slip, and extension and strike-slip compound) were recognized. Accumulation of oil and gas in Qingdong Sag is influenced by structures and reservoir and cap rock conditions. Six oil and gas accumulation systems were found, which are north fault terrace-north subdepression oil and gas accumulation system, west slope belt and gas accumulation system, middle Horst oil and gas accumulation system, south Horst oil and gas accumulation system, drape structural belt of Qingdong 2 well oil and gas accumulation system, and Qingnan area oil and gas accumulation system. Members 3 and 4 of the Shahejie Formation are the main target of hydrocarbon source rocks because the organic matter abundance is up to the standard of good hydrocarbon source rocks. The north of the Qingdong Sag and second slope-break belt should be the key objectives of exploration in the future.     

苏北盆地古近系阜三段物源特征及其形成的构造背景分析

综合碎屑组分、砾石成分、稀土元素、砂岩含量分布和砂砾岩分布特征的分析,并借鉴前人的研究成果,可以得出,苏北盆地古近系阜三段的物源区主要有6个。(Ⅰ,Ⅱ)建湖隆起分别向南北两侧供源:向南为金湖东部凹陷、高邮北部凹陷和海安凹陷供源,母岩成分主要为中酸性火成岩、石英岩和花岗岩;向北为盐城凹陷供源,母岩成分主要为中酸性火成岩、石英岩、基性火成岩和花岗岩,与建湖隆起南侧相比,存在基性火成岩的混入。(Ⅲ)张八岭隆起向东为金湖西部凹陷供源,母岩成分主要为中酸性火成岩和石英岩,与建湖隆起南侧母岩相比,缺少花岗岩成分。(Ⅳ)苏南隆起向北为高邮南部凹陷供源,母岩成分主要为碳酸盐岩和中酸性火成岩,与高邮北部凹陷母岩成分有差异,存在大量碳酸盐岩成分的混入。(Ⅴ)滨海隆起向南为阜宁凹陷供源,据调研,母岩主要为中深变质岩和古生界沉积岩。(Ⅵ)据调研,鲁苏隆起东段为涟北凹陷供源,主要为浅变质酸性火成岩。结合Bhatia稀土元素特征参数对比和Dickinson构造背景判别图解,认为源区构造背景属于与大陆岛弧相关的活动大陆边缘和再旋回造山带。     

珠江口盆地白云凹陷地温场特征及烃源岩热演化

通过对珠江口盆地白云凹陷108口钻井的地温数据(BHT、MDT、DST)进行校正、分析,以点到面重构白云凹陷的现今地温场,再结合地质与地球化学资料,正演恢复白云凹陷烃源岩的热演化史及生烃史.研究结果显示:(1)白云凹陷具有变地温场,地温梯度分布在35～60℃/km之间,呈现出南高北低的分布特征.(2)受控于白云凹陷变地...     

二连盆地侏罗系烃源岩地球化学特征及油源贡献

二连盆地侏罗系烃源岩研究程度较低,但在侏罗系发现有工业油流.本文通过有机岩石学与有机地球化学常规分析,系统研究与评价了此套烃源岩;结合原油与烃源岩的生物标志化合物的对比与分析,探讨其对油源的贡献.结果表明,二连盆地上侏罗统烃源岩有机质丰度低,有机质类型以Ⅲ型为主,成熟度较低,为非或差烃源岩;中下侏罗统有机质丰度较高,有机质类型以Ⅱ2-Ⅲ型为主,成熟度较高,为较好—好烃源岩.侏罗系烃源岩形成于淡水的氧化沉积环境,以陆源高等植物输入为主.此外,阿56井阿尔善组部分原油和图参1井侏罗系原油来源于侏罗系烃源岩.由此推断二连盆地侏罗系烃源岩具有良好的生烃潜力,勘探前景广阔.     

吐哈盆地台北凹陷西山窑组（J2）孢粉组合

台北凹陷是吐哈盆地的主要含油气区,而西山窑组煤系地层是该地区的主力烃源岩。对采自葡１井与草南１井西山窑组孢粉化石的,鉴定和统计,共发现孢粉化石31属57例,依据属种含量分布和地史意义,可建立以Cyathiites－Cycadopites－Quadraeculina为代表的孢粉组合,其中裸子植物花粉略占优势,含量为51％,蕨类植物孢子含量为49％。通过对主要孢粉类型和重要属种地史分布的讨论、与邻区及国内外同时代孢粉组合特征的对比,加之本区西山窑组与下伏早侏罗世晚期的三工河组为整合接触关系,认为西山窑组孢粉组合与陕甘宁盆地中部地区的延安组、辽宁西部的海房沟组等地层所产孢粉组合较相似,其地质时代应属中侏罗世早期,大致相当Aalenian－Bajocian期。     

Hydrocarbon maturation modeling of Paleocene to Lower Miocene source rocks in the Niger Delta Basin: implications for hydrocarbon generation

This study evaluates the hydrocarbon generation potentials and time of generation for Paleocene to Lower Miocene source rock horizons from A-1, B-1, B-2, and C-1 wells in the Niger Delta Basin using 1D Petromod modeling software. Wells A-1, B-1 and B-2, and C-1 are located within the Central Swamp, the Coastal Swamp, and the Shallow Offshore depobelts, respectively. The thermal history was derived from the rifting–subsidence heat flow model. Maturity modeling were carried out by using Easy%Ro kinetic model and a heat flow history predicting present-day heat flow which were calibrated with measured temperature data. Results of the study suggest that these potential source rocks have attained maturity status to generate hydrocarbons, with vast differences existing in the timing of the onset of oil generation. Basin modeling suggests that Paleocene source rocks entered the oil generative window from the Oligocene to Miocene times with thermal maturity window that varies from gas generation to early-mature phase. The Eocene source rocks have also attained maturity from Miocene to Pliocene times, and their thermal maturity ranges from gas generation to early maturity stage. The Oligocene source rocks also began to generate oil during the Miocene and are currently within the early-mature to mid-mature stage. The thermal maturity window for the Lower Miocene source rocks ranges from immature to early-mature stage. The present modeling results reveals that higher levels of thermal maturity are attained in areas with high geothermal gradients and heat flow values while the cooler areas exhibits lower levels of maturation. The onset of the oil window lies at 2859 m at A-1 (Central Swamp), 3240 m at B-2 (Coastal Swamp), 4732 m at B-1 (Coastal Swamp), and 4344 m at C-1 (Shallow Offshore). The depth to the onset of oil window is found deeper in the Shallow Offshore and western parts of the study area than in the eastern and northwestern parts. The result of this study suggest that the Paleocene, Eocene, Oligocene, and Lower Miocene source rocks are the principal source rocks for oil and gas generation in the Niger Delta Basin.     

新疆准噶尔盆地东北缘石炭系姜巴斯套组烃源岩评价

准噶尔盆地东北缘石炭系烃源岩主要分布在准东和腹部地区,根据野外地表调查,针对准噶尔东北缘石炭系烃源岩有机质丰度、类型、成熟度特征进行了综合研究和评价,研究区烃源岩主要为灰黑色碳质粉砂质泥岩、泥岩。结果表明:该区石炭系烃源岩有机质丰度总体上属差-中等烃源岩。姜巴斯套组下段烃源岩有机质类型主要为Ⅰ型;中段烃源岩有机质类型以Ⅱ1、Ⅲ为主;上段有机碳含量较低,据相关变化趋势推测其有机碳类型为以Ⅲ型为主。因此总体上有机质类型为Ⅱ2-Ⅲ型。有机质成熟度总体上属成熟-高熟,主要为高熟。综上所述,准噶尔东北缘的石炭系是一套较有效的烃源岩,在该区寻找油气具重要意义。