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1.
The origin and source of the petroleum in the Jurassic reservoirs within the eastern Fukang sub-depression were geochemically investigated. They show thermal maturities matching the peak generation stage, while the condensates are at the early stage of intense cracking. Oils and condensates may have experienced mild evaporative fractionation, while mixing of severely biodegraded with non-biodegraded oils has occurred. Using biomarkers and isotopes, petroleums were classified into Group I, II and III genetic groups, with Group III further divided into IIIa and IIIb subgroups. Group I petroleum displays heavy carbon isotopes, a strong predominance of pristine over phytane, high C19 and C20 tricyclic and C24 tetracyclic terpanes, low gammacerane, and dominant C29 steranes, while Group II shows light carbon isotopes, a predominance of phytane over pristine, high C21 and C23 tricyclic with low C24 tetracyclic terpanes, high gammacerane and dominant C27 steranes. Group IIIa petroleum shows mixing compositions of Group I and II, while Group IIIb displays similar compositions to Group I, but with significantly higher Ts, C29Ts and C30 diahopane proportions. Oil-source rock correlation suggests Group I and II petroleums originate from Jurassic and Permian source rocks, respectively, while Group IIIa are mixtures sourced from these rocks and IIIb are mixtures from Jurassic and Triassic source rocks. 相似文献
2.
Walter E Reed 《Geochimica et cosmochimica acta》1977,41(2):237-247
Two surface outcrop samples and three drill core samples of oil-impregnated sandstone from the P.R. Spring Seep, Uinta Basin, Utah were analyzed. These oils exhibit in common the entire homologous series of tricyclic diterpane hydrocarbons, which have been previously described only in extracts from the Mahogany Ledge Member of the Green River Formation. Hopane and a series of degraded hopanes are also present in the oil samples, while steranes are conspicuously absent. Aliphatic alkanes are present only in the deepest core sample.The cycloalkanes are apparently not readily utilized by the petroleum oxidizing microbes, and therefore survive the weathering process. Tricyclic and tetracyclic alkylated diterpanes are unchanged, whereas the series from norhopane through tetrakisnorhopane may be interpreted as progressive bacterial degradation of the hopane molecule.The occurrence and distribution of tricyclic diterpanes, of tetracyclic diterpanes and pentacyclic triterpanes is similar to the stratigraphically nearby Mahogany Ledge Member, suggesting that the oil shales were the source rocks for the oil now exposed as the P.R. Spring Seep. The absence of steranes, which are abundant in the oil shales, is puzzling. 相似文献
3.
C.M. Ekweozor J.I. Okogun D.E.U. Ekong J.R. Maxwell 《Journal of Geochemical Exploration》1981,15(1-3)
The analyses, by gas chromatography and gas chromatography/mass spectrometry, of the triterpane concentrate of crude oils sampled from various oil fields of the Tertiary Niger delta have revealed the ubiquitous presence of a series of C24–C27 tetracyclic alkanes likely to be novel degraded triterpanes. The presence in the crude oils of a C25 tricyclic alkane, apparently structurally related to the tetracyclanes, seemed consistent with the hypothesis of sequential cleavages of the terminal rings of precursor pentacyclic triterpenoid derivatives with increasing thermal transformation of the respective petroleums.The degraded triterpanes might be useful for assessing the stages of thermal evolution of petroleum in the reservoir. A possible application, to oil exploration, of the expected variations in the concentration of the polycyclanes in crude oils with different thermal histories would be in distinguishing primary (immature) oils from mature but biodegraded oils. 相似文献
4.
A series of tricyclic terpenoid carboxylic acids (C20–C40) was found in the acidic fraction of Tasmanian tasmanite bitumen, occurring as a mixture of stereoisomers with mainly the 13β(H), 14α(H)-and 13α(H),14α(H)-configurations. These dominant acidic tricyclic constituents have the same carbon skeleton as the ubiquitous tricyclic terpane biomarkers. A novel series of ring-C monoaromatic tricyclic terpenoid carboxylic acids was also characterized. The series ranges from C19 to C39 and is the acidic counterpart of the recently described series of monoaromatic tricyclic terpanes. 相似文献
5.
J.Michael Moldowan Wolfgang K. Seifert Emilio J. Gallegos 《Geochimica et cosmochimica acta》1983,47(8):1531-1534
A series of tricyclic terpanes from C19 to C45 has been identified in petroleum by gas chromatographic mass spectroscopic (GCMS) analysis. This discovery extends the previously known homologous series reported from C19 to C30. A method of preparation of a tricyclic terpane concentrate is described which facilitates tricyclic terpane analysis by the GCMS m/z 191 fragment. Metastable scanning GCMS is described as an additional method for characterization of the tricyclic terpanes. 相似文献
6.
The bicyclic terpanes reported to be present in numerous petroleums have been detected in the saturate fraction of the Athabasca oil sand bitumen. This series of compounds has been found to extend from C15 to at least C24 and their structures have been established by means of comparisons with synthetic C18 and C20 samples of known stereochemistry. 相似文献
7.
8.
Gross compositions and distribution of saturated and aromatic hydrocarbons in Carboniferous sandstone reservoire rocks in oil and water zones for Tzhong-10 well of the Zhongyang Uplift in the Tarim Basin were studied in dteail by means of Rock-Eval Pyrolysis,thin-chromatograph-flame ionization detection(TLC-FID),gas chromatography,gas chromatography-mass spectrometry.The results suggest that the gross composition of reservoir hydrocarbons between the oil zone and the water zone show significant differences,Water wahing has a dramatic effect on saturated hydrocarbon blomarkers,especially drimane series compounds,Drimane series compounds in the water zone have been depleted completely.However,the contents of tricyclic iterpanes and pentacyclic triterpanes tend to decrease slightly,but the water-zone reservoir hydrocarbons contian a large amount of gammacerane.This suggests that gammacerane be more resistant to water washing than diterpanes and homohopanes.The contents of pregnane,homopregrane,diasteranes relastively decrease as a result of water washing.Water washing has a noticeable effect on polycyclic aromatic hydrocarbon compounds,especially aromatic sulfur compounds,and the contents of dibenzothiophene series compounds and benzonaplyiothipophene decrease significantly as a result of water washing.However,the conterts of bicyclic and tricyclic aromatic hydrocarbons decrase slightly and those of tetracyclic and pentacyclic aromatic hydrocarbons,especially benzofluoranthene and benzopyrenes,increase markedly owing to adecrease in light aromatie hydrocarbons as a result of water washing. 相似文献
9.
在分析东营凹陷缓坡带孔店组多个原油样品的类异戊二烯烷烃、甾类化合物、萜类化合物和碳同位素构成的基础上,揭示了孔店组原油的典型地球化学特征。孔店组原油甾类化合物主要由规则甾烷构成,异构化程度较低,明显富有C29规则甾烷;三环萜烷相对含量高,三环萜烷/五环萜烷分布范围为0.15～0.53;碳同位素组成偏轻,δ13Ｃ值普遍小于－29‰。由于孔店组原油与研究区已认定的Esx3亚段、Ess4亚段和Ek2亚段三套生油岩都缺少成因联系,该区可能存在一套尚未落实的生油岩。依据原油的典型生物标志化合物构成特征推断,孔店组原油应来自下第三系深层一套贫粘土矿物且富含化学盐岩的生油岩层。 相似文献
10.
Suryendu Dutta Monalisa Mallick Runcie Paul Mathews Ulrich Mann Paul F. Greenwood Rakesh Saxena 《Journal of Earth System Science》2010,119(5):711-716
The terpenoid composition of resins from the Miocene lignite horizons from the Kerala-Konkan Coast, western India was analyzed
by Curie-point pyrolysis-gas chromatography-mass spectrometry (Cupy-GC-MS). The major pyrolysates were cadalene-based bicyclic
sesquiterpenoids including some C30-C31 bicadinenes and bicadinanes typical of dammar resin from angiosperm plants of Dipterocarpaceae family. These plants are typically
supported by tropical climates which the western Indian region was known to have experienced during early Tertiary period.
The present study suggests that these palaeoclimatic conditions persisted until at least the Miocene epoch. These sesquiterpenoids
which are commonly detected in many SE Asian crude oils may be utilised as useful biomarkers for petroleum exploration in
the western Indian region. 相似文献
11.
塔里木盆地一类新海相原油的地球化学特征 总被引：1，自引：0，他引：1
对塔中52等井奥陶系储层产出的原油进行的分析结果表明,它们的三环萜烷系列较为特殊,主要表现为其相对丰度呈C19>C20>C21>C23>C24>C25>C26阶梯状的模式,C24四环萜烷异常丰富,且其丰度远高于C26三环萜烷,这一分布模式一般出现在淡水沼泽相和浅湖相沉积地层与原油中。在三萜烷分布特征上,其伽马蜡烷含量很低,甾烷系列和藿烷系列的分布与组成特征与该地区来源于中上奥陶统烃源岩的海相原油十分接近,同时它们的全油均具有轻的碳同位素组成,其δ13Ｃ值都小于-30‰,具有海相成因原油的特征。而塔中12井上奥陶统良里塔格组4-5段烃源岩中生物标志物的分析结果进一步证实了该类原油与那些富含宏观藻残片,且有机质类型偏腐殖型的上奥陶统海相烃源岩关系密切,是该地区油气勘探中值得关注的对象。 相似文献
12.
The Qinjiatun and Qikeshu oilfields are new Mesozoic petroleum exploration targets in Lishu Fault Depression of Songliao Basin, northeastern China. Currently, researches on geochemistry of crude oils from Qinjiatun and Qikeshu oilfields have not been performed and the genesis of oils is still uncertain. Based on bulk analyses, the crude oils in the Qinjiatun and Qikeshu oilfields of Lishu Fault Depression from the Lower Cretaceous can be classified as three types. TypeⅠoils, from Quantou and Denglouku formations of Qikeshu oilfield, are characterized by high C24tetracyclic terpane/C26tricyclic terpanes ratios, low gammacerance/C30hopane ratios, tricyclic terpanes/hopanes ratios, C29Ts/C29norhopane ratios and 17α(H)-diahopane/17α(H)-hopane ratios, indicating a brackish lacustrine facies. TypeⅡoils, from Shahezi Formation of Qikeshu oilfield show low C24tetracyclic terpane/C26tricyclic terpanes, high gammacerance/C30hopane ratios, tricyclic terpanes/hopanes ratios, C29Ts/C29 norhopane and C30diahopane/C30hopane ratios, thus suggesting that they originated from source rocks deposited in a weak reducing brackish lacustrine environment, or clay-rich sediments. Type oilsⅢ, from some wells of Qikeshu oilfield have geochemical characteristics intermediate between those two types and may be mixture of typeⅠand Ⅱoils. 相似文献
13.
以贵州纳雍地区下寒武统牛蹄塘组黑色页岩为研究对象,分析其中的生物标志化合物。结果表明：奇偶优势(OEP)均值为1.08,接近平衡值1.00,无明显奇偶优势,姥鲛烷与植烷比(Pr/Ph)均值小于1,具明显的植烷优势;萜烷丰度顺序为五环三萜烷>三环萜烷>四环萜烷,规则甾烷以C27略占优势,ΣC27/ΣC29的均值为1.41,大于1,显示有机质来源以浅海相菌藻类等低等水生生物为主;C32αβ22S/(22S+22R)平均值为0.59, Ts/(Ts+Tm)值为0.43,βα-莫烷/αβ-藿烷平均值为0.124,C29甾烷的20S/(20S+20R)平均值为0.39,C29甾烷αββ/(αββ+ααα)平均值为0.41,均表明纳雍地区黑色岩系中的有机质均接近或达到成熟阶段。根据这些特征可以推断,该区域早寒武世牛蹄塘组黑色岩系形成于浅海还原环境,有机质热演化程度较高,其母质主要来源于细菌、藻类等低等水生物。 相似文献
14.
19-Norisopimarane and isopimarane have been synthesized from isopimara-9(11), 15-diene-3β, 19-diol. Analysis of the alkane fractions of an Australian crude oil by GC-MS showed the presence of nine diterpenoid hydrocarbons (diterpanes), of which one was bicyclic two were tricyclic and six were tetracyclic.19-Norisopimarane and isopimarane were identified by comparison of their mass spectra and GC retention times with those of the synthetic standards. ent-Beyerane, 16a(H)-phyllocladane, 16)β(H)-phyllocladane, ent-16α(H)-kaurane and labdane were also identified by comparison with authentic reference compounds. The remaining two compounds were tentatively identified as rimuane and as a 17-nortetracyclic diterpane on the basis of mass spectral evidence. The diterpanes are probably derived from conifer resins. 相似文献
15.
The aliphatic, aromatic and polar (NSO) fractions of seabed petroleums and sediment bitumen extracts from the Guaymas Basin hydrothermal system have been analyzed by gas chromatography and gas chromatography-mass spectrometry (free and silylated). The oils were collected from the interiors and exteriors of high temperature hydrothermal vents and represent hydrothermal pyrolyzates that have migrated to the seafloor by hydrothermal fluid circulation. The downcore sediments are representative of both thermally unaltered and thermally altered sediments. The survey has revealed the presence of oxygenated compounds in samples with a high degree of thermal maturity. Phenols are one class of oxygenated compounds found in these samples. A group of methyl-, dimethyl- and trimethyl-isoprenoidyl phenols (C27-C29) is present in all of the seabed NSO fractions, with the methyl- and dimethyl-isoprenoidyl phenols occurring as major components, and a trimethyl-isoprenoidyl phenol as a minor component. A homologous series of n-alkylphenols (C13-C33) has also been found in the seabed petroleums. These phenols are most likely derived from the hydrothermal alteration of sedimentary organic matter. The n-alkylphenols are probably synthesized under hydrothermal conditions, but the isoprenoidyl phenols are probably hydrothermal alteration products of natural product precursors. The suites of phenols do not appear to be useful tracers of high temperature hydrothermal processes. 相似文献
16.
Abundant tricyclic diterpanes (i.e., pimarane, dehydroabietane and simonellite) and tetracyclic diterpanes (e.g., phyllocladane) were detected in coal samples from the third member of the Shahejie Formation, Lower-Eogene, Liaohe Basin, China. Gas chromatography–isotope ratio mass spectrometry (GC–IRMS) analyses show that the carbon isotopic composition of terrigenous tricyclic and tetracyclic diterpenoid hydrocarbons are about 4–6‰ enriched in 13C compared to n-alkanes in the same samples. In addition, the pimaranes and phyllocladane have comparatively narrow stable carbon isotopic compositions among the different samples, with a slightly wider range in δ13C compositions for the abietanes (i.e., abietane, dehydroabietane and simonellite). The n-alkanes and triterpenoids reflect the δ13C compositions of higher plant wax. 相似文献
17.
V.A. Kashirtsev A.E. Kontorovich V.L. Ivanov A.F. Safronov 《Russian Geology and Geophysics》2010,51(1):72-82
In the northern and northeastern Siberian Platform, within the Anabar and Olenek zones, there are a number of hypergene bitumen accumulations (fields) and natural bitumen seeps, whose total resources are estimated at >5 bln tons. Bitumen fields are confined to a wide stratigraphic range from Precambrian to Mesozoic. A detailed geochemical study was performed for bitumens of the largest Olenek field, whose naphthides are localized mainly in Permian sandstones of deltaic and coast-marine genesis. Chromato-mass spectrometric analysis showed that normal alkanes are drastically reduced in the saturated fraction of the bitumens and most of terpanes are a homologous series of 25-norhopanes, which evidences the intense bacterial degradation of hydrocarbon pools. Identification of bicyclic sesquiterpenes, tetracyclic onocerane, and other biomarkers testifies that the organic matter of source rocks was rich in higher-plants remains. The concentrations of steranes are low, whereas those of earlier unknown 8-14-secosteranes are rather high. The set of geochemical data on the Permian bitumens of the Olenek field, including the isotopic characteristics of carbon (δ13C of ?25.8 to ?31.3‰), suggests that the coeval oil source rocks on the passive continental margin (at the place of the present-day Verkhoyansk fold belt) were the main source of hydrocarbons for the field. Assessment of oil and gas resources, including giant bitumen pools, and their exploration in the framework of “The fundamentals of Russian state policy in Arctic up to 2020” have become a top-priority problem. Petroleum refining products might be economically feasible raw materials in the eastern Russian Arctic sector to be supplied via the Northern Sea Route. 相似文献
18.
现代沼泽沉积物中三、四环萜类的分布及演化特征 总被引：2，自引：0，他引：2
对甘南和滇池现代沼泽沉积物中三、四环萜类的研究表明:在现代沼泽沉积物中,具类海松烷骨架的化合物以海松烷型化合物数量最多,而松香烷型化全物数量较少;长链三环萜烷中存在C21C23和C24化合物以C23为顶点的倒“V”字型分布,正常四环萜烷呈以高碳数为主峰的“阶梯型”分布,有意义的的是样品中均含脱-A-羽扇烷和壳松烷四环萜烷。在早期成岩过程,海松烷型二萜类主要是形成烯烃和烷烃,而松香烷型二萜类主要是芳构化作用。 相似文献
19.
HPLC extracts of crude petroleums and of marine recent sediments, containing the monomethyl-phenanthrene series, are examined by high resolution spectrofluorimetry in n-hexane at 15 K (Shpolskii effect). Identification and relative quantification of each of the five isomers is obtained on six natural samples. The distribution of the monomethyl-phenanthrenes and the relative absence of 4-methyl-phenanthrene in petroleums compared to marine sediments may reflect steric inhibitions. 相似文献
20.
对渤海湾盆地一系列生物降解原油的色谱-质谱分析结果表明,庙西凹陷PL15-8D与PL9-4井四个严重生物降解原油三环萜烷系列分布较为异常,主要表现为以C23为主峰的后峰型、C20与C23为主峰的微弱双峰型以及以C20与C24为主峰的双峰型分布模式。强烈的生物降解作用导致C19~C23三环萜烷优先于C24+三环萜烷被不同程度地侵蚀,是形成这一异常分布的根本原因。三环萜烷系列相对丰度与绝对浓度的变化规律表明,不同碳数三环萜烷的生物降解作用同时发生,但其降解速率有明显差别,即抗生物降解能力不同。三环萜烷系列化合物（除C20三环萜烷以外）的抗生物降解能力具有随碳数增加而增强的趋势,而C20三环萜烷抗降解能力似乎强于C21~C23三环萜烷。原油中未检测到脱甲基三环萜烷,表明三环萜烷的降解并非通过微生物的脱甲基化作用,推测其降解途径是微生物氧化三环萜烷C环支链末端的甲基,形成对应的羧酸化合物。四个原油样品甾烷、藿烷与三环萜烷被微生物严重侵蚀,不能用于油源对比研究,而三芳甾烷未受生物降解影响,可作为研究区严重生物降解原油油源对比的有效指标。 相似文献