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1.
应用高分辨率质谱分析苏丹高酸值原油成因 总被引：3，自引：1，他引：2
苏丹Muglad和Melut盆地是苏丹乃至整个中、西非剪切带最富含油气的盆地,所发现的原油主要为中质油(重度为20°～34°API),其次为重质油(重度小于20°API),普遍高含沥青质、高含蜡、高酸值、低含硫。为了探讨高酸值原油的成因,选择了苏丹地区18个不同酸值的原油样品,尝试高分辨率质谱分析上述原油有机酸的组成。结果表明,高酸值原油的有机酸主要由环烷酸组成;环烷酸的平均相对分子质量随降解作用程度增加而增大,分子碳原子数分布范围变宽;环烷酸以一环、二环、三环环烷酸为主。生物降解作用是形成高酸值原油的主要原因。 相似文献
2.
乍得Bongor强反转裂谷盆地高酸值原油成因 总被引：1，自引：1，他引：0
乍得Bongor盆地是受中非剪切带影响发育起来的中、新生代陆内强反转裂谷盆地,反转和走滑构造是盆地最显著的构造特征。所发现的原油主要为中质油(重度为20°～34°API),其次为重质油(重度小于20°API),普遍高含沥青质、高含蜡、高酸值、低含硫。为了探讨高酸值原油的成因,作者选择了该盆地15个不同酸值的原油样品,尝试应用高分辨率质谱分析原油有机酸的组成。分析结果表明,高酸值原油的有机酸主要由环烷酸组成;环烷酸碳原子数分布范围较宽,且以一环、二环、三环环烷酸为主。生物降解作用是形成高酸值原油的主要原因,而构造反转造成盆地抬升,则加速了生物降解作用的发生。 相似文献
3.
G.T Philippi 《Geochimica et cosmochimica acta》1977,41(1):33-52
Paraffinic crude oils are designated ‘primary’ because their composition is very close or identical to that of the hydrocarbons extracted from the corresponding oil source rocks. Heavy and medium-gravity naphthenic crude oils, on the other hand, typically are quite different compositionally from hydrocarbon mixtures in either mature or immature shales.The normal paraffin carbon number odd/even ratio 2C29/(C28 + C30) of all the heavy to medium-gravity crude oils which could be analysed are in exactly the same range as is observed for the primary paraffinic crude oils, namely 0.95–1.42. The naphthene indices of the medium to heavy gravity naphthenic crude oils and of the primary paraffinic crude oils from the same area are identical or close. These facts are significant because both the n-paraffin carbon number odd/even ratio and the naphthene index of shale hydrocarbons are strongly depth and subsurface temperature dependent. The facts observed demonstrate beyond question that, in the same area, the paraffinic precursors of the heavy to medium-gravity naphthenic crude oils are generated and expelled in the identical depth range, and from the same mature relatively deep oil source beds as the primary paraffinic crude oils. Later, during and/or after a generally upward migration into oil reservoirs, the primary crude may be transformed compositionally into a naphthenic crude oil.In none of the five widely scattered oil basins studied are medium to heavy naphthenic crude oils found at temperatures greater than a limiting subsurface temperature. The abruptness of the temperature cutoff of the change in oil compositions in all five oil basins, as well as the average value of the cutoff temperature of 66°C (150°F), leaves no doubt that the mechanism of this crude oil transformation process is microbial.Optical activity, which was observed in narrow saturate hydrocarbon fractions of the 80–325°C range of all microbially transformed crude oils, but not in the primary untransformed oils, is strong additional evidence for the microbial nature of the crude oil transformation process. The observed optical activity is explained by the microbial digestion at different rates of optical antipodes present in the primary paraffinic crude oils.To gain perspective the vast scale of the microbial oil transformation process in nature is pointed out. Billions of tons of heavy to medium-gravity naphthenic crude oils, originating from the microbial transformation of primary paraffinic oils, are present in oil fields and tar sands all over the world. 相似文献
4.
We generalized experimental data on the structural group composition and macrostructural characteristics of high-molecular compounds (HMCs)—hydrocarbons, resins, and asphaltenes—from more than 180 crude oil samples extracted from different oil fields of Eurasia. Most of oil resin molecules contain 1–3 structural blocks, each consisting of 0–3 aromatic and 0–5 naphthenic rings in different combinations, with the total number of rings in each block not exceeding 5–6. The average molecular weights of resins are no more than 100–1500 a.m.u. Asphaltenes differ from resins from the same source in the larger number of structural blocks (mainly tri- or tetracyclic aromatic) in molecule (up to five), lower degrees of substitution of aromatic cores, and smaller portions of carbon atoms in saturated fragments. The average molecular weights of asphaltenes measured by naphthalene cryoscopy do not exceed 2500 a.m.u. Owing to intermolecular interactions, HMCs form various associates and polymolecular particles, including quasi-crystalline “batches” and multibatch aggregates. Spontaneous disintegration and formation of such particles make the oils dynamically equilibrium polydisperse systems. We have developed the main regularities of compositional and structural changes of HMCs depending on the depth of occurrence, age, and lithologic composition of oil-bearing deposits. Being chemically labile heteroatomic substances, petroleum HMCs are more rapidly subjected to compositional and structural transformations than hydrocarbons, i.e., are more responsive to changes in strata conditions. 相似文献
5.
《International Geology Review》2012,54(1):42-48
The author analyzes data on the contents of naphthenic acid in crude oils. Characteristics and properties of naphthenic acids in oils of adjacent formations are compared. The final conclusion denies the existence of any general relationship between the content of naphthenic acids and the depth of occurrence of oils of the deposits of the Apsheron Peninsula. --Royer and Roger, Inc. 相似文献
6.
Tanja Barth Sylvi Hiland Per Fotland Kjell Magne Askvik Bent Skaare Pedersen Anna Elisabet Borgund 《Organic Geochemistry》2004,35(11-12):1513
Twelve oil samples have been characterised by titration, FT-IR and chromatographic analysis to determine the differences between the organic acid composition of biodegraded and non-biodegraded oils. The biodegraded oils have higher total acid and total base contents, both by titration and extraction. The molecular weight ranges of the extracted acids are lowest in the biodegraded oils, and the equivalent weight calculations indicate a dominance of multi-functional molecules. Gel permeation chromatography gives a molecular weight range with most of the molecules between 300 and 500 g/mol. FT-IR shows that the extracted acids from biodegraded oils are more carboxylic and aliphatic while the non-degraded oils are more phenolic. Molecular analysis of the derivatised extracts give UCM envelopes for biodegraded oils, and no molecular identification. The results indicate that the acidic constituents in biodegraded oils are a product of the biodegradation, as the composition is very different from the non-biodegraded oils. 相似文献
7.
塔里木盆地哈拉哈塘凹陷东侧轮古地区有丰富的海相稠油产出,其中包括大型的塔河油田群,在凹陷的西北缘也有海相稠油发现。凹陷东侧海相稠油的地球化学成因已经有较多的研究报道,而西北缘针对海相稠油的研究工作仍然十分薄弱,其地球化学成因仍需深入探讨。本工作以哈拉哈塘凹陷东西两侧的稠油LG7井和DH1－6－9井为例,对比研究其地球化学特征,重点对比分析稠油沥青质中吸附／包裹烃类化合物的地球化学应用。研究结果表明凹陷东西两侧的稠油藏至少经历了两期油气的充注,其中第一期充注来自同一套烃源岩,后期遭受了,严重的生物降解改造;第二期充注来自另一套烃源岩,其正构烷烃仍然具有完整的分布模式。凹陷两侧稠油经历了相似的后期成藏过程,在西北缘相应的构造单元中可望发现更多海相来源的油气资源。 相似文献
8.
9.
Sulphur-containing compounds in sulphur-rich crude oils from hypersaline lake sediments and their geochemical implications 总被引：1，自引：0，他引：1
Guoying Sheng Jiamo Fu S. C. Brassell A. P. Gowar G. Eglinton Jaap S. Sinninghe Damste Jan W. de Leeuw P. A. Schenck 《中国地球化学学报》1987,6(2):115-126
Three sulphur-rich commercial crude oils have been studied, which contain sulphur as high as up to 4–12%. These samples were
collected from Tertiary hypersaline lake sediments of the Jianghan Basin, Hubei Province at different depths, but above the
oil generation threshold (2200m). FPD-GC and GC-MS data show that aromatic fractions of the crude oils are composed of different
homologues of sulphur-containing compounds, including long-chain normal alkyl-thiophenes and-thiolanes, long-chain isoprenoid-thiophenes
and -thiolanes, and benzothiophenes. It is worth noting that the distribution patterns of long-chain alkyl-thiophenes and
-thiolanes from two shallow-seated crude oils are quite similar to those of normal alkanes showing marked even-odd predominance.
It seems that the even-odd predominance of sulphur-containing compounds decreases with increasing burial depth of the crude
oils. The major component of aliphatic fraction is phytane, and similarly the major peaks of aromatic fractions also represent
C20 isoprenoid thiophenes.
Some preliminary conclusions have been drawn from the above discussion: (1) Abundant sulphur-containing compounds may be used
as an indicator of low mature or immature crude oils produced from hypersaline lake sediments; (2) Sulphur-containing compounds
are considered to be early diagenetic products of reactions between elemental sulphur or sulfides and alkanes or their precursors
(phytols, fatty acids, alcohols, etc.), or of bacterial activities, but not direct inputs of organisms. 相似文献
10.
中国西北侏罗纪煤系显微组分热解油生物标志物特征及其意义 总被引：4，自引：0，他引：4
从西北地区侏罗纪煤中分离出来的不同显微组分热解油生物标志物总体上比较相似,但在一些特殊生物标志物的分布上存在明显差异。藻类体、孢子体、角质体热解油Pr/Ph比值一般在1.5～2.0之间,镜质体和基质镜质体热解油Pr/Ph比值在3～4之间,但均只有相应原煤抽提物Pr/Ph比值的一半。在常规生物标志物甾烷和萜烷组成中,藻类体和孢子体含有相对丰富的C27甾烷,角质体其次,镜质体和基质镜质体C27甾烷含量很低或者基本不含C27甾烷;藻类体和角质体含有较高的伽马蜡烷,而与藻类体来自相同原煤的孢子体伽马蜡烷含量很低;镜质体和基质镜质体基本上不含伽马蜡烷;分离显微组分的原煤伽马蜡烷含量均很低。由此可见,伽马蜡烷的含量不仅与有机质沉积水体的盐度有关,与母源的成分也有关系。显微组分热解油与煤系原油生物标志物组成特征对比表明,煤系原油是藻类体、孢子体、角质体等富氢组分和相对贫氢的镜质组生成产物的混合物。不同油气藏中的原油,每一类显微组分的贡献可能不尽相同,有些原油可能主要来源于藻类体和孢子体等富氢显微组分,而有些原油除了富氢显微组分有贡献外,镜质组对其也有一定的贡献,但富氢显微组分应该是煤系含油气盆地中主要的生油显微组分。 相似文献
11.
John B. Curtis Maciej J. Kotarba Michael D. Lewan Dariusz Wi&#x;c&#x;aw 《Organic Geochemistry》2004,35(11-12):1573
The Oligocene Menilite Shales in the study area in the Polish Flysch Carpathians are organic-rich and contain varying mixtures of Type-II, Type-IIS and Type-III kerogen. The kerogens are thermally immature to marginally mature based on atomic H/C ratios and Rock-Eval data. This study defined three organic facies, i.e., sedimentary strata with differing hydrocarbon-generation potentials due to varying types and concentrations of organic matter. These facies correspond to the Silesian Unit and the eastern and western portions of the Skole Unit. Analysis of oils generated by hydrous pyrolysis of outcrop samples of Menilite Shales demonstrates that natural crude oils reservoired in the flysch sediments appear to have been generated from the Menilite Shales. Natural oils reservoired in the Mesozoic basement of the Carpathian Foredeep appear to be predominantly derived and migrated from Menilite Shales, with a minor contribution from at least one other source rock most probably within Middle Jurassic strata. Definition of organic facies may have been influenced by the heterogeneous distribution of suitable Menilite Shales outcrops and producing wells, and subsequent sample selection during the analytical phases of the study. 相似文献
12.
John K. Volkman Robert Alexander Robert Ian Kagi Garry Wayne Woodhouse 《Geochimica et cosmochimica acta》1983,47(4):785-794
Analyses of some Australian crude oils show that many contain varying concentrations of A/ B-ring demethylated hopanes. These range from C26 to C34 and have been identified from their retention times and mass spectral data as 17α(H)-25-norhopanes. Comparison of hopane and demethylated hopane concentrations and distributions in source-related, biodegraded oils suggests that demethylated hopanes are biotransformation products of the hopanes. Further, it appears that the process occurs at a late stage of biodegradation, after partial degradation of steranes has occurred. Demethylated hopanes are proposed as biomarkers for this stage of severe biodegradation. The presence of these compounds in apparently undegraded crude oils is thought to be due to the presence of biodegraded crude oil residues which have been dissolved by the undegraded crude oil during accumulation in the reservoir sands. The timing of hopane demethylation, relative to the degradation of other compounds, has been assessed and the progressive changes in crude oil composition with increasing extent of biodegradation have been identified. The use of demethylated hopanes as maturity parameters for severely biodegraded crude oils, and the applicability of established biomarker maturity parameters to such oils, are also discussed. 相似文献
13.
This paper deals with natural temperature records in the heavy (asphaltenes) and the light fractions (C7—light hydrocarbons) of petroleum. Two sets of marine oils formed from different source rocks and petroleum systems were studied using asphaltene kinetics and light hydrocarbon analysis. Both fractions have been reported to contain information about the temperature the respective oils have been exposed to in the subsurface. These indicated temperatures generally correspond to the conditions in the source rock when expulsion occurred. Bulk kinetic analysis of reservoir oil asphaltenes as well as light hydrocarbon (LH) analysis (of dimethylpentanes) were used here in order to evaluate the expulsion temperatures. Surprisingly, when considering information coming from both fractions, an inverse trend between LHs expulsion temperatures (Ctemp) and asphaltenes (Tasph.) can be observed—high Tasph (asphaltene temperatures) occur with low LH Ctemp (light hydrocarbon expulsion temperatures) and low Tasph can be observed when Ctemp is high. These differences are of fundamental importance for the use of such geochemical data in calibrating numerical basin models. The reason for this inverse behaviour is possibly due to the different expulsion behaviour of light hydrocarbons and the heavy fraction of oils, especially when the source rocks contain only moderate amounts of organic matter. In addition it has to be considered that the temperature predictions obtained using asphaltene kinetic analysis are related to the onset temperature of petroleum expulsion, while light hydrocarbons provide, at best, average expulsion temperatures. 相似文献
14.
Based on experimental and observational evidence, a mode of origin involving evaporative fractionation is proposed for a class of petroleums enriched in light aromatic and naphthenic hydrocarbons (benzene, toluene, meta-xylene, para-xylene, methylcyclopentane, cyclohexane, and methylcyclohexane). Progressive gas loss from gas-saturated oil is suggested as the causal mechanism, with simultaneous loss of light ends in gaseous solution, and accompanying fractionation. These processes were simulated experimentally.Residual oils exhibit the following changes in their remaining light hydrocarbons, <C9: (1) increase in aromaticity (in aromatic hydrocarbons relative to normal alkanes of molecular weight); (2) increase in “normality” (in unbranched alkanes and naphthenes relative to branched isomers), and (3) decrease in paraffinicity (in paraffins relative to naphthenes). Retrogressive changes in maturity indicators take place leading to spurious evidence of immaturity in residual oils and the derived evaporative condensates.The phenomena occur in many basins, and are a key to understanding major aspects of petroleum variability. On the basis of aromaticity and paraffinicity relationships, evaporative gas-condensates are distinguishable from those generated by thermal cracking. Unfractionated thermal gas-condensates are rare. Evaporative condensates are the daughter products of oils which have suffered evaporative fractionation. 相似文献
15.
东海盆地西湖凹陷轻质原油芳烃地球化学特征 总被引：4，自引：1，他引：3
采用GC-MS实验技术,对西湖凹陷8口井12个轻质原油样品的芳烃地球化学特征进行了系统研究。平湖斜坡带北部地区NB14-1井、NB14-2井和NB14-3井这3口井的轻质原油与平湖斜坡带中部地区的NB25-1井和NB25-2井、西次凹的HY1-1井以及黄岩构造带的HY2-1井和HY2-2井这5口井的轻质原油芳烃化合物的分布特征和相对含量存在明显差别。轻质原油芳烃馏分中以二环和三环的化合物为主,前者富含菲系列化合物,萘系列和联苯系列化合物含量相对较低,后者则相反,其富含萘系列和联苯系列化合物,菲系列化合物含量相对较低。轻质原油生源和沉积环境的研究表明,原油的母源都主要为陆源高等植物来源,成因环境都为氧化环境,但后者的1,2,5-TMN和1,2,5,6-TeMN相对含量更高,氧芴相对含量和Pr/Ph值更大,反映其母源的陆源高等植物输入程度更大,沉积环境的氧化性更强。烷基萘、烷基菲和烷基二苯并噻吩成熟度指标表明,轻质原油以达到成熟到高熟演化阶段,平湖斜坡带北部地区的NB14-1井、NB14-2井和NB14-3井这3口井的轻质原油热演化程度相对更高。 相似文献
16.
塔里木盆地原油中二苯并噻吩的分布及主力油源岩类型判识 总被引：2，自引：0，他引：2
在塔北隆起大部分地区和塔中隆起发现的工业油气流具有与海相下古生界（奥陶系）油源岩相同的地球化学特征，且含有十分丰富的二苯并噻吩类有机硫化物。本文详细研究了世界各地若干典型海相碳酸盐岩和泥页岩来源油中二苯并噻吩（ＤＢＴｓ）的分布。发现新参数二苯并噻吩脱甲基指数（ＤＤＩ）和甲基重排指数（ＤＭＩ）受成熟度影响小，能有效地区分油源岩岩性。根据ＤＢＴｓ的相对含量和ＤＤＩ及ＤＭＩ指标判识，表明塔里木盆地下古生界原油主要来自碳酸盐岩，奥陶系广海陆棚台地相喑色泥晶灰岩是主力油源岩。这一认识将有助于确认主力油源区的分布，具有较大的勘探意义。 相似文献
17.
Ercin Maslen Kliti Grice Pierre. Le MétayerDaniel Dawson Dianne Edwards 《Organic Geochemistry》2011,42(4):387-398
The present study aims to establish the factors controlling the stable carbon isotopic compositions (δ13C) of individual aromatic hydrocarbons analysed by compound specific isotope analysis (CSIA) in crude oils from western Australian petroleum basins of varying age and facies type. This paper reports δ13C values of individual aromatic hydrocarbons, like alkylbenzenes, alkylnaphthalenes, alkylphenanthrenes and methylated biphenyls. The main aims are to confirm the origin (source) and age of these oils based on CSIA of selected aromatic compounds and to understand why the Sofer plot is ineffective in establishing the source of western Australian petroleum systems. The bulk δ13C of saturated and aromatic hydrocarbon fractions of crude oils have been previously used to differentiate sources, however, many Australian crude oils are not classified correctly using this method. The oils were classified as marine by the δ13C values of individual aromatic compounds and as terrigenous based on the bulk δ13C data (Sofer plot).The oils where the δ13C values of 1,6-DMN and 1,2,5-TMN isomers are most negative are indicative of a marine source, whereas oils with a less negative values for the 1,6-DMN and 1,2,5-TMN isomers are derived from marine source rocks that contain a significant terrigenous component. Similarly, oils with the least negative δ13C values for the 1-MP and 1,9-DMP isomers reflect varying inputs of terrigenous organic matter to the their marine source rocks. Plots of P/DBT and Pr/Ph concentration ratios versus δ13C values of DMP, 1,6-DMN, 1,2,5-TMN, 1-MP and 1,9-MP are constructed to establish the relative amount of terrigenous organic matter contributing to the source rock of a series of marine oils. The ratios of P/DBT and Pr/Ph plotted against the δ13C values of the aromatic isomers (such as 1,6-DMN, 1,2,5-TMN, 1-MP and 1,9-MP) provide a novel and convenient way to discriminate crude oils derived from different source rocks that contain varying amounts of marine and terrigenous organic matter. 相似文献
18.
Ger Van Graas 《Organic Geochemistry》1986,10(4-6)
Biomarker distributions in a suite of asphaltenes and kerogens have been analysed by flash pyrolysis directly coupled to a GCMS system. Attention has been focussed on biomarkers of the sterane and triterpane types. The sample suite under investigation consists of sediments with different kerogen types and some crude oils. Biomarker distributions in the pyrolysates have been compared with the “free” biomarkers in the corresponding saturated hydrocarbon fractions.The analyses show significant differences between the distributions of the free biomarkers and those in the pyrolysates. The latter have lower amounts of steranes while diasteranes are absent or present at low concentrations only. In the triterpane traces a shift of maximum intensity from C30 (free compounds) to C27/C29 is observed. Furthermore, the pyrolysates contain a set of triterpenes (not present among the free compounds), and there is a selective loss of “non-regular” triterpanes that are present in the saturated hydrocarbon fractions. The observed differences between pyrolysates and free hydrocarbons can be explained partly by the processes occurring during pyrolysis such as bond rupture and subsequent stabilisation of primary pyrolysis products. To a certain extent these differences also show that maturation processes occurring in sediments have effects on free biomarker molecules different from those on molecules that are enclosed in a macromolecular matrix (kerogen or asphaltenes).Differences between biomarker distributions of asphaltene and kerogen pyrolysates are relatively small. A comparison with the pyrolysates from extracted whole sediments suggests that these differences are mainly caused by interactions between the organic material and the mineral matrix during pyrolysis.Oil asphaltenes behave differently from sediment asphaltenes as their pyrolysates are more similar to the corresponding saturated hydrocarbon fractions, i.e. the differences described above are observed to a much smaller extent. This different behaviour appears to be the result of coprecipitation of a part of the maltene fraction with the oil asphaltenes. 相似文献
19.
南堡凹陷滩海区深部古生界已相继发现数口高产工业油气流井,其性质不同于上伏第三系原油。采用地质地球化学方法相结合途径,对油气特征与成因进行了剖析。已发现潜山原油主要为高蜡油、其次为凝析油。GC、GC/MS分析表明,潜山原油中链烷烃组分含量较高、甾萜类生标含量较低且异构化程度较高;富含重排甾烷、重排藿烷与18a（H）-新降藿烷（Ts）与C29Ts;部分生标如升藿烷系列有明显热裂解现象,指示潜山原油较高的成熟度。油-油、油-岩对比表明,潜山原油与沙二+三段烃源岩有成因联系。供烃方式主要包含近距离-烃源岩直接披覆于潜山及源-储通过断层对接供烃、远距离-断层和风化壳运移输导两种。南堡凹陷潜山高蜡油的形成主要与烃源岩主要为Ⅱ2-Ⅲ型有机质类型有利于提供蜡质烃以及深部奥陶系油气藏极可能遭受气洗有关。气洗迹象包括低分子量链烷烃被切割、萘系列相对丰度低于菲系列,出现“倒转”等反常现象。南堡凹陷潜山油气特征与成因研究有助于揭示该区深部油气藏的形成机制及开展深部油气资源评价。 相似文献
20.
Six oils and seven suspected source rocks from the Jianghan saline basin, in the central eastern part of China, have been examined using a variety of geochemical techniques. The results from this study show that oils from the third and fourth sections of the Qianjiang Formation (Eocene) are derived from similar source materials but have a different source from the oils of Xingouzui Formation (Eocene) in the same basin. The oils of the Xingouzui Formation (Eocene) are more mature, and probably have a greater input of terrigenous source material and in all probability have migrated greater distances than the Qianjiang oils. Oils from these sections are derived from an environment characterized as being extremely anoxic, strongly reducing and highly saline. The suspected source rocks examined in the study were from the Qianjiang Formation and were generally mature, except for the shallowest sample. The biomarker distributions in the suspected source rocks examined from the Qianjiang Formation were very different from those of the oils present in the same sections. It is proposed that oils from the Qianjiang Formation have sources in addition to, or exclusive of, the suspected source rocks examined in this study. 相似文献