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41.
系统采集鄂尔多斯盆地南部中生界的烃源岩、原油及油砂样品,对其饱和烃和芳烃馏分进行气相色谱-质谱分析,通过 对生物标志物组成特征的研究,分析和探讨中生界原油的油源。结果表明:根据 8β(H)-补身烷和 C3017α(H)-重排藿烷含量, 鄂尔多斯盆地南部中生界原油可划分为I,II,III类。第I类原油 8β(H)-补身烷含量高, C3017α(H)-重排藿烷含量低,来自 深湖相沉积相带的长 7 油页岩 (A1 类),第II类原油 8β(H)-补身烷含量较高, C3017α(H)-重排藿烷含量中等,来自深湖—半深 湖沉积相带的长 7 暗色泥岩 (A2 类),第III类原油 8β(H)-补身烷含量低, C3017α(H)-重排藿烷含量高,来自半深湖沉积相带的 长 7 暗色泥岩 (A3 类),由于采集样品数量限制,第III类原油不排除来自长 8 或长 9 暗色泥岩 (A3 类) 的可能,目前发现的原油 主要是第I类,即各油层组的原油主要是由长 7 油页岩提供的,它是鄂多斯盆地南部中生界的主力烃源岩。  相似文献   
42.
滇东罗平地区中三叠统中发现液态油苗   总被引:1,自引:0,他引:1  
张启跃  周长勇  吕涛  谢韬 《地质通报》2009,28(10):1526-1532
通过1∶5万区调填图,在云南罗平地区中三叠统关岭组二段薄层泥晶灰岩中首次发现液态油苗。该稠油显示主要分布在层间晶洞中,表现为干沥青及稠油共存状态。有机地球化学研究表明,氯仿沥青“A”的含量为67×10-6,有机质类型以腐泥型Ⅰ型为主。镜质体干酪根反射率R0为2.84%,Tmax=568℃,表明有机质处于高成熟阶段。液态油苗的显示对于进一步评价南盘江盆地的油气勘探前景具有重要的价值和意义。  相似文献   
43.
Application of organic petrology and geochemistry to coal waste studies   总被引:1,自引:0,他引:1  
Coal wastes produced during mining activities are commonly deposited in nearby dumps. These wastes mostly composed of minerals and variable amounts (usually 20-30%) of organic matter start to weather immediately after deposition. Oxidation of the organic matter can lead to self heating and self combustion as a result of organic and mineral matter transformations. The degree of alteration depends on the properties of the wastes, i.e., the maceral and microlithotype composition of the organic matter and its rank.Alteration of wastes also depends on the heating history, i.e., the rate of heating, final heating temperature, duration of heating, and the degree of air access. Although air is probably necessary to initiate and drive the heating processes, these usually take place under relatively oxygen depleted conditions. With slow heating, color of organic matter particles changes, irregular cracks and oxidation rims develop around edges and cracks, and bitumen is expelled. As a result, massive and detritic isotropic and strongly altered organic matter forms. On the other hand, higher heating rates cause the formation of devolatilization pores, oxidation rims around these pores and along cracks, vitrinite-bands-mantling particles, and bitumen expulsions.Organic compounds generated from the wastes include n-alkanes, iso-alkanes, alkylcyclohexanes, acyclic isoprenoids, mainly pristane, phytane and, in some cases, farnesane, sesquiterpanes, tri- and tetracyclic diterpanes, tri- and pentacyclic triterpanes, and steranes, polycyclic aromatic hydrocarbons (mostly with two- to five rings, rarely six rings), and phenols. The compounds formed change during the heating history. The fact that phenols are found in dumps where heating has not yet been completed, but are absent in those where heating ceased previously suggests the presence of water washing. The organic compounds formed may migrate within the dumps. However, when they migrate out of the dumps, they become a hazard to environment.This paper is a review on transformations of organic matter (both maceral composition and reflectance and chemical composition) in coal wastes deposited in coal waste dumps. Immediately after deposition the wastes are exposed to weathering conditions and sometimes undergo self heating processes.  相似文献   
44.
陈中红  查明  金强  任拥军 《沉积学报》2011,29(1):173-183
为研究实际地质体或地质剖面中的C31到C3517α(H), 21β(H)升藿烷生物标志物构型转化参数22S/(22S+22R)及升藿烷指数C35/∑(C31—C35)等的分布、演化特征,对东营凹陷主要烃源岩层系古近系沙河街组三段(淡水—微咸水层系)和沙河街组四段(咸水层系)的系列样品进行了研究,分析样品来源于1 300~4 000的暗色泥岩,其中2 800~4 000 m的样品对应于东营凹陷古近系烃源岩的生油初期到生油晚期。研究结果表明,C31、C32、C33、C34、C35升藿烷(17α(H), 21β(H))构型转化参数的分布除与异构体之间的手性碳立体构型转化作用有关外,不同异构体之间降解或裂解速率和新生成速率的差异也是其主要控制因素,沉积环境(如高盐环境)也在一定程度上影响了其分布;从未熟—低熟状态到成熟状态,相关升藿烷构型转化参数22S/(22S+22R)总体均表现出随埋藏深度增大而加大的特点,并从离散状态聚集到热演化的平衡状态附近;在到达成熟状态后,相关升藿烷的构型转化参数22S/(22S+22R)从缓慢增大过渡到一个持续的热演化平衡状态,并且该构型转化参数的热演化平衡状态对应于生油门限附近;在高盐环境中除C33升藿烷保持不变的热演化平衡状态外,其它升藿烷均呈现不同幅度的逆转特征,表明高含量的盐类矿物对升藿烷成熟度参数亦具有抑制作用或迟缓效应;C31、C32、C33、C34、C3517α升藿烷之间的22S/(22S+22R)分布型式复杂多变,其中对于成熟源岩样品,C35升藿烷22S/(22S+22R)值变化强烈,表现出“翘尾”状的上升型特征和“坠尾”状的下降型特征,而对于低熟—未熟样品, C32升藿烷的22S/(22S+22R)显示相对高值,并且多数样品显示为C31C33C35的偶数碳优势的特征;研究显示C31到C33升藿烷的构型转化参数S/(S+R)热演化平衡值均为0.6,而C34 S/(S+R)及C35S/(S+R)热演化平衡值相对较高,沙三段、沙四段的C34 S/(S+R)及沙四段的C35S/(S+R)分别达到0.63、0.62、0.65;升藿烷指数C35/∑(C31—C35)受热演化影响也比较明显,在生油期间随着埋藏深度增加而减小,在高盐环境中表现出相对高值,研究表明该指数的变化与其22R异构体演化有关,并且参数C31/∑(C31—C35)、C32/∑(C31—C35)、C33/∑(C31—C35)、C34/∑(C31—C35)、C35/∑(C31—C35)演化特征截然不同。  相似文献   
45.
The primary focus of this paper is to better understand carbon burial on the Louisiana continental margin using spatial scales that covered various shelf depositional areas far-field and near-field (sediment and organic carbon inputs relative to river mouth proximity) and covering a variety of sedimentation rates. Box-cores samples were collected in July 2003; cores were collected along two depositional transects extending westward and southward from the Southwest Pass (SW Pass). A key difference between the two transects sampled in this study was the greater occurrence of mobile muds derived from spillover from shallower regions along the westward 50 m isobaths. The dominant mechanism for mixing in the surface active zone (SAZ) on the inner Louisiana shelf was due to physical, not biological, forces. Burial efficiencies for organic carbon (57.2–91.5%) and total nitrogen (44.2–86.9%) ranged widely across all shelf stations. Lower burial efficiencies for bulk organic carbon, total nitrogen, and pigment biomarkers were associated with mobile muds west of Southwest Pass. Chlorophyll a concentrations were significantly higher than pheopigments at depth at the Mississippi River and Southwest Pass stations, making up 40.4 and 77.4% of total pigment concentrations in the (SAZ) and 46.2 and 63.2% in the accumulation zone (AZ), respectively. These results are in agreement with earlier plant pigment studies which showed that a large fraction of the phytodetritus delivered to the inner shelf was derived from coastal and river diatoms. The amount of lignin preserved with depth decreased with increasing residence time in the SAZ and diagenetic zone (DZ) along the canyon transect but not along the western transect. Trends for lignin concentration followed previously identified surface sediment trends indicating overall lower burial of refractory terrestrial material at depth with greater distance offshore.  相似文献   
46.
双壳类分子生物标志物对海水重金属的响应评述   总被引:1,自引:0,他引:1  
海洋双壳类动物的组织和器官对微量重金属具有高富集能力,诱导机体内的某些分子生物标志物(molecular biomarkers,MBMs)发生变化,可用于指示海水中的重金属污染水平。近10年来,许多学者在双壳类MBMs对海水重金属的响应规律方面进行了研究,其中,金属硫蛋白(MTs)、热激蛋白70(HSP70)、抗氧化防御系统等受到了较多的关注。本文在介绍这些MBMs结构和功能的基础上,重点评述了各种MBMs对海水重金属的响应特征,并提出了影响双壳类MBMs应用于海水重金属监测的因素及进一步研究的方向。  相似文献   
47.
48.
High-temperature gas chromatography (HTGC) has enhanced our ability to characterize hydrocarbons extending to C120 in crude oils. As a result, hydrocarbons in waxes (> C20) have been observed to vary significantly between crude oils, even those presumed to originate from the same source. Prior to this development, microcrystalline waxes containing hydrocarbons above C40 were not characterized on a molecular level due to the analytical limitations of conventional gas chromatography. Routine screenings of high pour-point crude oils by high-temperature gas chromatography has revealed that high molecular weight hydrocarbons (> C40) are very common in most oils and may represent 2% of the crude oil. Precise structures, origins, and significance of these high molecular weight compounds remain elusive. As a preliminary step to expand our knowledge of these compounds their general molecular structures and formulas have been investigated in this study. Initial results suggest that the major high molecular weight compounds include a homologous series of n-alkanes, methylbranched alkanes, alkylcyclopentanes, alkylcyclohexanes, alkylbenzenes and alkylcycloalkanes.  相似文献   
49.
运用有机岩石学、有机地球化学、催化加氢热解、GC—IRMS等方法和技术,深入研究了川东北飞仙关组储层固体沥青及可能烃源岩的地球化学特征。研究认为,飞仙关组储层固体沥青反射率高,双反射明显,为非均质结构储层焦沥青;在碳酸盐岩储层的各种孔隙中,呈脉状、球粒状、角片状或块状等他形充填,具有中间相结构和镶嵌状结构特征,反映其高温热变质成因;元素组成有S/C高、H/C低的特点,其固体碳同位素组成与长兴组烃源岩干酪根相似。储层固体沥青的可能烃源岩发育于还原—弱氧化咸水沉积环境,有机质来源于水生藻类;氯仿沥青“A”饱和烃甾萜类生物标志物对比表明,上二叠长兴组烃源岩是主要来源,飞仙关组、下志留统烃源岩亦有贡献;催化加氢产物饱和烃及其正构烷烃单体碳同位素组成显示,坡2井飞仙关组储层固体沥青与罐5井飞仙关组烃源岩具有明显的亲缘关系,这也可作为飞仙关组海槽相烃源岩对飞仙关组气藏有贡献的佐证。  相似文献   
50.
Core samples were collected in Lagoa Vermelha, a hypersaline lagoon located about 100 km east of Rio de Janeiro (Brazil). The sediment composition is predominantly carbonate in amounts up to 93%. Analysis of δ13C of the total organic matter in the sediments showed that marine organic matter predominates throughout the core (δ13C ranges from −15.84 to −22.64‰ vs. PDB). Organic carbon contents (TOC) ranged from 0.81 to 13.28%. A series of cadinane-type sesquiterpenoids can be recognized in the gas chromatography-mass spectrometry data. Essentially the same components are present in all the samples, with variations only in their relative abundances. The most abundant compounds are α- and β-cubebene, α- and β-cedrene, cadinenes (different isomers), α-curcumene and calamenene, with minor amounts of calarene, humulene, calacorene and cadalene. Since this lagoon is surrounded by dunes with only minor vegetation typical of this environment (grasses, small non-resinous shrubs and no forest) with no potential source for sesquiterpenoids, a terrestrial origin for these compounds is excluded and an algal origin is more consistent with the locale and the recognition of sesquiterpenoids (including cadinol) in microbial mats from the lagoon. Only the natural product precursor sesquiterpenoids are present in the microbial mats with no detectable diagenetic derivatives (e.g. calamenene and cadalene). This indicates that the compounds in the mats are from recent input and those found in the sediments are most likely derived from former algal biomass in this lagoon, a fact confirmed by the recognition of a series of diagenetic aromatic components in the sediments. Surface sediments contain n-alkanes with no even-to-odd predominance indicating that microbial activity is higher in shallower sediments. Moreover, mass fragmentograms (m/z 191) of biomarkers revealed the presence of 17α(H),21β(H)-hopanes, the mature isomers, together with their ββ precursors and low amounts of the intermediates with the βα configuration (moretanes). This indicates a contribution of mature organic matter to these immature sediments.  相似文献   
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