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1.
泥岩的元素特征能够较好地保存于原始沉积记录。为了明确恩平21洼文昌组泥岩元素地球化学特征及其与有机质富集的关系,选择YJ-1井文昌组10个泥岩岩屑样品,开展有机碳、常量元素和微量元素测试。在分析常量、微量元素地球化学特征的基础上,利用元素地球化学方法,系统分析洼陷文昌期古气候、古水深、古氧相和古生产力等古环境指标。文昌组泥岩元素平均含量对UCC(Upper Continental Crust)做标准化处理,恩平21洼文昌组泥岩具有富集Al2O3、K2O和MnO,贫CaO、MgO和Na2O;富Li、Be、Zn、Rb、Cs、Ba、Pb、Th和U,贫Sr、V和Cr的特征。古环境指标显示恩平21洼文昌期气候属于温暖湿润-温热潮湿,湖泊水深相对较深,纵向水深变化小,水体分布稳定,水体以还原环境为主,古生产力相对较高,但纵向差异大。泥岩有机碳含量与古生产力参数相关性较差,而与水体还原性之间具有较好的正相关关系,表明有机质富集受控于水体的氧化还原程度,水体还原条件有利于有机质的保存,有机质富集属于“保存模式”。进一步分析显示,古气候条件是文昌组有机质富集的关键性因素,温热潮湿的...  相似文献   

2.
综合运用地质、钻井、生物标志物、碳同位素、储层流体包裹体等资料,在油气分布特征和来源分析的基础上,探讨了控制西湖凹陷孔雀亭气田油气成藏及富集的主要因素。研究结果表明,孔雀亭气田油气主要分布在始新统平湖组储层内,具有"上油下气"的纵向分布特征,以断块型凝析气藏为主,原油及天然气来源于自身和西部次洼平湖组源岩联合供烃。孔雀亭气田油气成藏及富集主要受断层封堵性、砂体厚度和储层物性及流体充注历史的联合控制,断层封堵性控制了油气藏的含油气性,砂体厚度和储层物性制约了油气层厚度和含油气饱和度,流体充注历史决定了油气藏的现今赋存相态。  相似文献   

3.
南黄海海底沉积物饱和烃类地球化学特征及其指示意义   总被引:1,自引:0,他引:1  
南黄海海底沉积物正构烷烃分布具有3种类型:第1类以低碳数占优势,主要来源于以浮游生物和细菌为主的有机质;第2类以高碳数占优势,主要来源于以陆源高等植物蜡供应为主的有机质;第3类显示双峰特征,陆源高等植物蜡与浮游生物和细菌均具有一定的贡献。Pr/Ph比值的范围为0.174~0.753之间,显示植烷优势,代表还原环境,其中,一些Pr/Ph比值相对较高的站位也一定程度上反映了存在陆生高等植物的贡献。藿烷和甾烷组成指示,有机质主要来源于陆地植物,沉积物来源区所处的环境为大陆、港湾及河湾及其过渡环境。一些站位样品的藿烷和甾烷等相关参数显示,南黄海海底沉积物具有较高的成熟度,明显偏离现代生物所应有的藿烷和甾烷等相关参数范围,表明有石油源有机质混入的迹象,混入的石油源烃可能来自人类活动和海底油气渗漏。  相似文献   

4.
在烃源岩分布特征、有机质丰度、类型和成熟度分析的基础上,运用含油气盆地数值模拟技术,定量恢复了烃源岩热成熟演化史,探讨了油气差异分布特征。研究表明,文昌A凹陷各层系烃源岩分布广,厚度大,有机质丰度高;有机质类型文昌组偏Ⅱ1型,恩平组偏Ⅲ型,二者现今多处于高成熟—过成熟阶段。凹陷内烃源岩成熟时间早(文昌组约45.5Ma),现今成熟度高,以干气生成为主;凹陷边缘烃源岩成熟时间较晚(文昌组约30.0Ma),现今成熟度相对较低,以石油生成为主。凹陷现今油气差异分布的格局受制于有机质类型差异和热演化史不同,且下一步油气勘探方向,凹陷内以天然气为主,凹陷边缘以石油为主。  相似文献   

5.
对阜新凹陷白垩系源岩生烃基本条件进行了详细分析,并结合原油、天然气特征及油源对比研究,认为研究区存在浅湖相泥岩和沼泽相煤系源岩(由煤和泥岩构成)2种不同沉积环境下形成的烃源岩.2种源岩虽然层位不同,但在其有机质丰度和类型上并不存在较大的差异,生烃特征也基本相似,都具备成气为主、成油为辅的煤成烃特征,有机质成熟度及烃源岩的分布控制了源岩在整个演化过程中的生烃类型和数量.研究表明:在有机质受热演化的各个阶段,都会伴随着不同类型有机成因气的产出,未成熟阶段为煤型生物气,成熟—高成熟阶段主要为煤型热解气,还伴生少量的石油.  相似文献   

6.
伊通盆地莫里青断陷地温地压系统与油气成藏关系   总被引:3,自引:0,他引:3  
基于地温和地压实测数据及声波测井资料等,利用地温-地压系统的原理,对伊通盆地莫里青断陷的地温场、压力场及温压系统特征进行了剖析,并从油气生成、保存及分布角度探讨了温压系统与油气成藏的关系。研究表明,断陷内各区带地温梯度较高,有利于有机质的成熟与烃类生成;泥岩欠压实段主要出现在双阳组,强化了油气的封闭作用;斜坡带泥岩不发育异常压力,以毛细管压力封闭为主;莫里青断陷发育弱高压型复式温压系统,上下2套温压系统流体能量相差较小,油气垂向运聚活动很少,深部弱高压型温压系统内部最有利于油气富集成藏,双阳组含油气系统是最重要的勘探对象。  相似文献   

7.
熔体包裹体是在矿物生长过程中被包裹的硅酸盐小液滴,由于寄主矿物的保护,受最小程度的后期岩浆作用影响,可以有效的保留原始岩浆组成、地幔源区性质及岩浆演化过程等重要信息。熔体包裹体的研究可以弥补传统全岩因受后期复杂地质过程影响而导致部分信息失真的不足。文章简要总结了熔体包裹体的主要研究领域及分析测试技术,概述了国内外关于西太平洋典型弧后盆地火山岩中熔体包裹体研究的相关进展。冲绳海槽、劳海盆及北斐济海盆内熔体包裹体的研究证明了地幔源区不均一性的特征,明确了岩浆物质来源及俯冲物质在源区的加入;马里亚纳海槽和马努斯海盆熔体包裹体内挥发份研究指示了俯冲板片物质对弧后盆地岩浆源区挥发份组成的贡献;马努斯海盆熔体包裹体中金属元素浓度分析表明岩浆流体可为海底热液系统提供成矿金属;此外,马里亚纳海槽和冲绳海槽熔体包裹体测温实验反映出岩浆多期次的演化过程。尽管熔体包裹体在西太平洋弧后盆地岩浆活动的很多方面有了一定研究,但各弧后盆地研究参差不齐、综合研究程度低。将来在进一步完善熔体包裹体测试分析手段基础上,加大熔体包裹体在弧后盆地的研究力度,有助于我们更清晰地认识弧后盆地岩浆源区物质组成,明确俯冲作用下弧后盆地岩浆来源及物质转化机制。  相似文献   

8.
珠江口盆地浅水与深水区地质背景及油气成藏地质条件存在明显差异,其油气分布及油气运聚成藏机制具有显著不同的特点.(1)油气分布具“北油南气”的富集规律.浅水区北部裂陷带和东沙隆起及以北地区,地温梯度低、大地热流小,烃源岩有机质热演化处在油窗范围,以产大量石油为主伴少量油型气,故形成了以文昌、恩平、西江、惠州及陆丰油田群和...  相似文献   

9.
应用传统的地质填图方法寻找隐伏、半隐伏矿产难度越来越大,实践证明,应用化探方法寻找隐伏、半隐伏矿产成效显著,本文通过云南保山西邑幅1:5万水系沉积物地球化学特征研究发现:Pb、Zn、Hg、Cd等元素强富集,可作为主攻矿种;通过元素异常特征研究,并结合成矿地质条件及已知矿点信息认为:该区发育多组近南北向断裂和北西-南东向断裂,为成矿提供有利的空间,卧年寺组玄武岩的喷出为成矿提供了有利的热源及流体,岩性为鲕状灰岩、燧石灰岩灰质泥岩和泥灰岩的铺门前组-香山组、大寨门组和何元寨组地层为赋矿层位,在此基础上,开展了成矿预测,划分出大坝口铅锌银找矿靶区和下庙铅锌银找矿靶区,为区域地质找矿和区域工作部署提供了依据。  相似文献   

10.
环雷州半岛近海表层沉积物有机碳分布及其控制因素分析   总被引:1,自引:0,他引:1  
对环雷州半岛近海43个海底表层沉积物的总有机碳(TOC)、总氮(TN)、沉积介质条件(包括沉积物粒度)进行了分析,探讨了沉积物TOC、TN的区域分布特征以及影响有机碳分布的主要因素。结果表明,环雷州半岛近海海域海底表层沉积物有机碳含量在0~0.79%之间,平均值为0.26%。与中国其它近海海域相比,环雷州半岛大部分近海区域海底表层沉积物有机碳含量明显偏低,为有机质贫乏区,仅雷州半岛西南部流沙湾近海海域为TOC相对高值区。总氮含量也不高,在0.011%到0.100%之间,TOC与TN存在较强的正相关性,且平面上TOC与TN分布高度重合,显示氮元素主要以有机化合物形式存在。TOC/TN比值在5.1~14.3之间,表明沉积有机质具有陆源输入和海洋自生来源的混合特征,但以雷州半岛西侧北部及东侧中部海域受陆源有机质输入影响更大。大多数站位海底沉积物粒度构成以粉砂为主、粘土次之,少数站位以砂质沉积为主。沉积物有机碳含量与粘土及粉砂含量呈弱正相关性,与沉积物pH值、Eh值及砂含量呈弱负相关性,这表明海底沉积物有机质丰度受有机质来源输入、海底氧化还原状态和沉积水动力条件(沉积物粒度)等因素综合控制。  相似文献   

11.
The hydrocarbon migration and accumulation of the Suqiao deep buried-hill zone, in the Jizhong Subbasin, the Bohai Bay Basin, eastern China, was investigated from the perspective of paleo-fluid evidence by using fluid inclusions, quantitative fluorescence techniques (QGF), total scanning fluorescence method (TSF) and organic geochemical analysis. Results show that the current condensate oil-gas reservoirs in the study area once were paleo-oil reservoirs. In addition, the reservoirs have experienced at least two stages of hydrocarbon charge from different sources and/or maturities. During the deposition of the Oligocene Dongying Formation (Ed), the deep Ordovician reservoirs were first charged by mature oils sourced from the lacustrine shale source rocks in the fourth member of Shahejie and Kongdian Formations (Es4+Ek), and then adjusted at the end of Ed period subsequently by virtue of the tectonic movement. Since the deposition of the Neogene Minghuazhen Formation (Nm), the reservoirs were mainly charged by the gas that consisted of moderate to high-maturity condensate and wet gas sourced from the Es4+Ek lacustrine shale source rocks and mature coal-derived gas sourced from the Carboniferous-Permian (C-P) coal-bearing source rocks. Meanwhile, the early charged oil was subjected to gas flushing and deasphalting by the late intrusion of gas. The widely distributed hydrocarbon inclusions, the higher QGF Index, and FOI (the frequency of oil inclusions) values in both gas-oil and water zone, are indicative of early oil charge. In addition, combined with the homogenization temperatures of the fluid inclusions (<160 °C) and the existence of solid-bitumen bearing inclusions, significant loss of the n-alkanes with low carbon numbers, enrichments of heavier components in crude oils, and the precipitation of asphaltene in the residual pores suggest that gas flushing may have played an important role in the reservoir formation.  相似文献   

12.
对原油地球化学特征进行对比分析,将辽河西部凹陷兴隆台构造带原油划分成4种类型。各类原油的正构烷烃碳数分布曲线、甾萜类成熟度参数、Pr/Ph等指标有较大差异,并在该区呈规律分布。总体表现为第三系原油由南至北成熟度参数和Pr/Ph值呈降低的趋势,正构烷烃碳数从单峰变化为双峰分布;太古宇潜山内幕及潜山表层原油性质相似,其成熟度明显高于第三系原油。原油分布主要受控于南北洼陷生油层成烃演化差异及与断裂发育时期的相互配置关系。  相似文献   

13.
Earlier studies have shown the occurrence of anomalous amounts of methane in rocks associated with lead/zinc mineralization in a number of deposits in the British Isles and Europe. This has led to speculation that the gas may have originated either as a consequence of reactions involved in the mineralization process or as a result of maturation of the organic matter in the sediment or from a deep source. New data are presented showing the distribution of light hydrocarbon gases from fluid inclusions in minerals from the North and South Pennine Orefields which differ from those observed in the host rocks. Possible sources for the gases in the host rocks and the minerals are examined. Based on the close correlation between the distribution of the gases in the carbonate rocks of Northern England and the conodont colour alteration index map for the area, it is suggested that the anomalous amounts of methane gas in the Northern Pennine host rocks are the result of maturation prior to mineralization. The distribution of gases in the fluid inclusions in the minerals serves as a distinguishing feature, and two assemblages are recognized from the South Pennine Orefield, both of which are distinct from that of the Northern Pennines. It is concluded that these gases, trapped at the time of mineralization, originate as a consequence of reactions which occurred during mineral deposition.  相似文献   

14.
The Niudong Buried Hill Field, which lies in the Baxian Depression of the Bohai Bay Basin, is the deepest oil/gas accumulation in eastern China. Its Precambrian dolomite reservoir occurs at burial depths of 5860 m–6027 m. This paper attempts to document the hydrocarbon charging and accumulation history in this field, which could greatly enhance the understanding of the mechanisms for the formation of deep hydrocarbon accumulations. Our previous study of oil trapped in fluid inclusions has demonstrated that the ratio parameters of the fluorescence spectral intensities at 425 nm and 433 nm (Q425/433 ratio), and at 419 nm and 429 nm (Q419/429 ratio) can be more effective for revealing hydrocarbon charging history than the previously-used fluorescence parameters such as Lambda max and red/green quotient as well as fluorescence colors. The hydrocarbon charging and accumulation history in the Niudong Buried Hill Field was studied with an integrated approach involving the application of these two spectral parameters of petroleum inclusion fluorescence as well as utilization of other data including homogenization temperatures of aqueous inclusions coeval with petroleum inclusions, and cross-cutting relationships of cements and “oil veins” in pores and fractures. The results indicate that the dolomite reservoir in the Niudong Buried Hill Field experienced three episodes of hydrocarbon charging. In the first two episodes (between 38.5Ma and 25Ma), the low mature and mature oils, which were derived from source rocks in the Sha-4 Member of the Eocene Shahejie Formation, migrated into the reservoir, but part of them leaked out due to normal faulting at the updip margin of the buried hill. These early-charged oils were preserved mainly in small pores in micritic dolomites by oil-wettability and capillary pressure. In the Neogene, the basin subsided as a whole and local faults at the updip margin became inactive and played a sealing role. By approximately 13Ma, the source rocks became highly mature and the generated hydrocarbons then migrated into the reservoir and accumulated. Therefore, the last charging is the most important for hydrocarbon accumulation in the Niudong Buried Hill Field.  相似文献   

15.
油气成藏分析是确定沉积盆地油气资源和勘探部署的重要研究内容之一。我们从有机包裹体研究入手,结合成藏作用模拟,分析丽水凹陷油气运聚成藏过程。包裹体分析结果表明该区油气主要运聚成藏期为E2末期,新近纪至现今也有一定的油气运聚。通过成藏作用模拟,认为该区油气主要运聚成藏期可分为3期:E1、E2和N-Q。根据成藏特点,将该区划分出4种主要成藏模式,即凹中隆多期充注原生油气藏成藏模式、东次凹西斜坡原生油气藏成藏模式、西次凹西斜坡原生油气藏成藏模式和浅层次生油气藏成藏模式。同时,从油气生成、运聚、成藏特点出发,将该区划分出下部异常压力和上部正常压力成藏系统。不同成藏系统有较大的差异。  相似文献   

16.
渤海石油污染:来自表层沉积物中生物标志物的证据   总被引:3,自引:0,他引:3       下载免费PDF全文
通过对渤海表层沉积物中饱和烃的分布、来源和分子组成特征的系统分析,探讨了沉积物中生物标志物对石油污染的指示意义。研究表明,沉积物中色谱不可分辨的混合物(UCM)和正构烷烃的分布及组成特征显示出沉积物不同程度地受到了石油烃输入和细菌微生物作用的影响,其中以渤海湾沿岸区域最为明显。渤海湾近岸区和黄河口附近沉积物中正构烷烃平均碳链长度(ACL)低于其他地区,姥鲛烷/植烷(Pr/Ph)也普遍低于1.0,表明可能受到来自于石油平台开采活动、船舶航行、河流输入的石油烃的影响。C27-18α(H)-三降藿烷(Ts)与C27-17α(H)-三降藿烷(Tm)的比值(Ts/Tm)、C31升藿烷22S/(22S+22R)和αααC29甾烷20S/(20S+20R)的比值表明该区域沉积物中有机质成熟度较高,可能受到外来石油烃输入及其衍生物的影响。通过与周边环境中生物标志物分子组成特征的对比发现,沉积物中甾烷和萜类化合物主要来源于石油及其衍生物。将饱和烃各参数进行归一化处理,得到了石油污染的综合替代性指标,并初步圈定了石油污染相对较重的区域。  相似文献   

17.
1 IntroductionWith the development of industry, more andmore petroleum energy sources are needed. The ex-ploitation of, especially benthal, develops quickly.The spilled oil accidents occur inevitably during oilexploitation and transportation. For example, in theBohai Sea, there are more than 1 000 oil wells andthe spilled oil accidents occur almost every year. Allkinds of dissension arose since the accidents couldnot be dealt with effectively in time. The key stepwhich affects the accidents …  相似文献   

18.
多环芳烃油指纹应用于船舶溢油鉴别研究   总被引:2,自引:0,他引:2  
溢油种类主要包括船舶燃料油和原油,二者性质的差异决定了鉴别方法也相应不同,寻求适合于船舶溢油的鉴别方法具有重要意义。在使用柱色谱层析方法对样品进行分离前处理的基础上,以气相色谱/质谱方法(GC-MS)为主要分析手段,对溢油样品和可疑船舶溢油源样品的多环芳烃油指纹特征进行对比,并在多环芳烃油指纹参数的基础上进一步进行多环芳烃内组成三角图分布特征与聚类分析研究,成功为珠江口水域某船舶溢油事故追踪到肇事溢油源。结果表明:取自丁船的油样和现场溢油样芳烃油指纹特征最为相近,是此次溢油事故的溢油源。受风化作用后的船舶燃料油中饱和烃类化合物数量稀少,且含量极低,不适合用于溢油鉴别,而多环芳烃类化合物较饱和烃类化合物而言具有含量高、种类丰富的特点,是该类溢油鉴别的主要油指纹依据。使用油指纹参数进行可疑溢油源识别时,充分考虑油品中有机分子所受风化影响程度的不同是风化条件下溢油鉴定的关键。因此,多环芳烃油指纹可以有效应用于船舶燃料油溢油的鉴别。  相似文献   

19.
The Erlian Basin is located in the Central Asia-Mongolian fold belt between the Siberian and Sino-Korean Cratons. It is a Mesozoic continental rift basin composed of 52 individual fault-depressions. The main phase of rifting took place during the Early Cretaceous when a series of fluvial-lacustrine sediments were deposited. Each depression forms an independent sedimentary system and behaves as an independent petroleum system. Hydrocarbon source rocks are found in the upper Arshan and lower Tengger Formations. These are mainly type II source rocks and are mainly located in oil generation window at the present day. A series of oilfields and commercial oil flows have been found in the basin, highlighting its good petroleum potential. Many of these oils are heavy.Six oil samples from the Anan and ten from the Jirgalangtu Depressions have been subjected to routine geochemical analytical techniques in order to evaluate the origins. The methods used include gas chromatography of the saturated and aromatic hydrocarbon fractions, gas-chromatography-mass-spectrometry of the saturated hydrocarbon fraction and stable carbon isotope analyses. The trace metal elements of the biodegraded oils from the Jirgalangtu Depression were also analysed by atomic absorption spectroscopy.Two types of heavy oils : primary and biodegraded were identified on the basis of these data. The former includes both immature and mature heavy oils. A filtering-and-spill process was proposed to explain the origin of primary mature heavy oils (or tar-mat) in the Anan Depression. The biodegraded oils from the Jirgalangtu Depression were ranked and classified in terms of the degree of biodegradation, using a series of geochemical parameters based on the gas chromatographic concentrations and biomarker fingerprints of gas-chromatography-mass-spectrometry of the saturated hydrocarbon fraction. The relationship between oil saturation and porosity indicates that the heavy oils in the Jirgalangtu Depression were biodegraded after they accumulated.  相似文献   

20.
Bacterial degradation of the hydrocarbons of lubricating oils was investigated by mass spectrometric analysis which gives both total amount and the composition of hydrocarbon types of residual oil. An unused lubricating oil, which mainly consisted of hydrocarbon types with only a small percentage ofn-alkanes, was degraded by marineBacillus sp. andPseudomonas sp. with 55 % and 25 % decreases in 10 days, respectively. Susceptibility of respective hydrocarbon types to biodegradation was in the following order: alkanes > non-condensed cycloalkanes, mono-aromatics > condensed cycloalkanes. A used lubricating oil of different brand showed a larger decrease than the unused oil. Both species of bacteria degraded large portions of alkane fraction of Arabian light crude oil.  相似文献   

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