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1.
腐殖煤气态产物演化特征的模拟实验研究   总被引:3,自引:0,他引:3  
高岗 《沉积学报》1998,16(2):30-41
本文较详细地探讨了成熟阶段腐殖煤在加水热模拟过程中气态产物的演化特征。成熟阶段的煤仍具有相当的生烃潜力,其主要生烃阶段仍以生油为主,生气相对较少。生油高峰之后由于液态产物的大量热裂解才开始进入气态烃的大量生成阶段。由于地质条件下煤中的可溶有机质十分丰富,在高演化阶段由可溶有机质进一步裂解是煤成气的重要来源。非烃主要形成于早期阶段。成熟煤生成的气态烃中甲烷为之主要成分,非烃中H2为主,其次为CO2,甲烷的碳同位素值明显低于乙烷,而乙烷和丙烷的碳同位素值差别较小,并且随演化程度的增加各气态组分的碳同位素值差别愈来愈小。  相似文献   

2.
中性含氮化合物的演化及地化意义   总被引:13,自引:0,他引:13  
通过对生油岩样品中的中性氮系列化合物含量和组成变化的系统研究。指出含氮化合物的热演化规律和形成机制。含氮化合物是沉积有机质成岩演化的产物。其含量和组成明显受控于有机质成熟度;认为1-/4-甲基咔唑,苯并[a]咔唑/苯并[c]咔唑等比值可作为成熟度参数。  相似文献   

3.
通过对盐生杜氏藻的热模拟成烃研究,发现其热解产物中含有丰富的咔唑系列化合物,它包括咔唑(CZ)、甲基咔唑(M CZ)、二甲基咔唑(DM CZ)、三甲基咔唑(TM CZ)、四甲基咔唑(TeM CZ)、五甲基咔唑(PM CZ)和六甲基咔唑(HM CZ)。并且在300℃热模拟产物中咔唑系列化合物含量较高,在芳烃馏分中相对含量为30.97%,350℃时产出较低,为15.44%,而250℃时未检出此类化合物。这一方面表明嗜盐杜氏藻很可能是原油和烃源岩中咔唑类化合物的主要母源之一,另一方面表明高盐环境下这种以杜氏藻为主要生烃母质的原油可能富集咔唑类化合物,这为该环境下油源对比提供了有力依据。  相似文献   

4.
金在气相中迁移与有机质演化生烃关系的实验研究   总被引:1,自引:0,他引:1  
火山喷气沉积物中微米级金的发现、化探地气测量检测出金等现象表明 ,在自然界金可在气相内存在。但是金以何种形式存在及其迁移机理尚待探讨。本项研究选取并制备了有地质意义的含硫有机金属化合物———烷基硫醇衍生纳米金 ,将其添加至含有机物质的自然样品中 ,在专门设计的真空加热装置中用泡塑收集其在不同温度条件下的气相产物 ,分析对比实验中产生的气相带出金的含量和气体成分 ,并与金的氯金酸水溶液作用过的样品进行对比。模拟与有机质密切相关的金在气相中迁移的地质过程。实验结果表明 ,含十二烷基硫醇衍生纳米金样品及其纯物质在升高温度条件下的气相产物带出金高于同样条件下用氯金酸处理过的含金样品。金的迁移与升高温度时产生的烃类气体有关。该实验为与有机质演化生烃有关的金气相迁移成矿过程提供了实验依据 ,由于十二烷基硫醇衍生纳米金中纳米金团簇是稳定存在于烷基硫醇结构内 ,因而实验也说明了金的纳米簇团迁移与有机质之间的密切关联。与有机质及其气相演化产物密切相关的金的气相迁移 ,是金在自然界呈气相迁移的重要形式之一。  相似文献   

5.
在密闭体系中700℃、压力高达3 GPa条件下进行褐煤加水的模拟实验,分析实验产物中的萜烷的变化规律,进而对高压高温下有机质演化进行研究.实验结果表明,相同压力条件下,温度升高有利于有机质的成熟演化;压力增加会抑制或延迟油气的生成和有机质成熟;五环三萜烷ββ生物构型转化为αβ地质构型所需能量比烯烃双键加氢饱和更高.高温超高压条件下,研究样品中C24四环萜烷存在4种同分异构体,含量由高到低依次包括10β(H)-降A-羽扇烷、10p(H)-降A-奥利烷、C24-17,21-断藿烷和10β(H)-降A-乌散烷.高碳数烷烃在地幔高压力条件下仍可以存在,这为认识超压盆地的油气资源与深层油气成藏及保存提供了新的思路.  相似文献   

6.
准噶尔盆地北三台地区北 82井、北 83井和沙 10 8井湖相原油咔唑类化合物的分布特征表明,油气运移作用是影响该区原油中咔唑类化合物分布的重要因素。沿油气运移方面,咔唑类化合物具有明显的分馏效应。总的趋势是原油中咔唑类化合物、高分子量的烷基咔唑化合物和苯并咔唑化合物的含量逐渐减少,低分子量咔唑和甲基咔唑,以及具屏蔽效应的二甲基咔唑和苯并 [a]咔唑异构体的相对含量则逐渐增加。利用咔唑类化合物的分馏效应,可有效地指示油气运移方向。  相似文献   

7.
富有机质泥页岩纳米级孔隙结构特征研究进展   总被引:6,自引:5,他引:1  
阐明富有机质泥页岩孔隙结构特征对阐明页岩油气的赋存机理和勘探开发具有重要的意义。研究泥页岩孔隙结构特征的方法主要包括定量和定性两类,实际研究中常将二者结合使用。有机质含量(TOC)、热演化程度、有机质母质来源、矿物组成及构造变形作用等因素对富有机质泥页岩孔隙结构特征有重要影响。有机质母质来源决定了纳米有机质孔的发育潜能,TOC和矿物组成控制了孔隙的发育类型,而热演化程度决定了孔隙的演化行为,构造变形作用对于纳米孔有后期改造作用。生排烃热模拟实验由于可以人为地控制实验条件,在泥页岩孔隙结构演化研究中扮演了重要的角色,但要注意与实际地质条件相匹配。目前,富有机质泥页岩孔隙结构的演化模式还存在较大的争议。受控于有机质母质来源,不同沉积环境下发育的富有机质泥页岩孔隙结构演化模式存在差异,因此需要分别研究。在未来工作中,TOC对泥页岩孔隙结构特征的影响、有机质孔开始形成的成熟度以及高演化阶段(镜质体反射率Ro>3%)孔隙的演化行为及机理等问题都需要进一步探究。另外,扫描电镜下识别有机质显微组成的方法亟需建立,同时还要规范行业术语的应用,以减少学科研究的混乱现象。  相似文献   

8.
沉积有机质热演化的本质是伴随H转移的歧化反应。有机S含量较高的干酪根具有更低生烃活化能,往往被认为是体系中丰富的含S自由基加速了C–C键断裂的结果。后生作用阶段,二苯并噻吩类化合物(DBTs)是有机S热演化的一类关键产物。因此,研究联苯类化合物(BPs)和单质S化合生成DBTs的反应过程,有助于理解在S自由基作用下,以H转移为基础的有机质生烃机理本质。本研究通过Gaussian09程序和3,3′-二甲基联苯(3,3′-DMBP)与单质S的热模拟实验,探索BPs和单质S反应生成DBTs的潜在反应路径。结果表明,S1自由基与BPs发生化合反应是优势反应路径,该过程进攻C–H键,形成DBTs和高活性的H自由基;除了部分H自由基参与生成H2S外,其余H自由基可以促进有机质裂解生烃。该优势反应路径表明, H转移更可能是后生作用阶段含S自由基促进沉积有机质裂解生烃的关键步骤。  相似文献   

9.
明确不同沉积环境下页岩气生成机理的差异性对于页岩气成因机理及页岩气地球化学特征研究具有重要意义.选择低演化阶段的海相(中元古界洪水庄组)和陆相(三叠统延长组长7段)泥页岩进行了半封闭热模拟实验,对其气体产物进行了组分和碳同位素分析.结果表明,洪水庄组页岩产气量要远远低于同温度条件下长7段泥岩的产气量.同时,长7段泥岩气体产物二次裂解程度比较高.洪水庄组页岩有机质母源以生油性为主,长7段泥岩沉积过程受到陆源混入,有机质母源以相对偏生气性为主.热模拟实验条件下黄铁矿转化成磁黄铁矿的过程也可能促进长7段泥岩烃类气的生成.热模拟实验中所用样品的状态,即柱状样或颗粒样,也可能会对气体的裂解行为产生影响.在这种情况下,南方地区页岩气高的甲烷产率以及碳同位素倒转可能与厚层页岩高的油气滞留率有关.   相似文献   

10.
辽河盆地东部凹陷中部沙一段和沙二段烃源岩主要处于成岩演化阶段,本文通过对其可溶有机质和干酪根的研究探讨了它们与过渡带气之间的关系,发现可溶有机质与同一样品的干酪根之间往往表现出不同的生源组成,前者以Ⅱb-Ⅲ型有机质为特征,而后者主要属Ⅰ-Ⅱa.型母质。在埋深1850~3060m的范围内,沥青A、非烃和沥青质的红外特征吸收及其有关参数呈一致的变化规律。由此划分出三个明显不同的演化阶段.并指出2200~2770m左右为沥青A、非烃和沥青质急剧降解的阶段,2500m左右达到高峰,其结果与过渡带气的形成密切相关。干酪根在该阶段虽然也表现出脱氧、脱脂基因特征,但以生成解聚沥青为主,与过渡带气不存在直接的联系。因此认为可溶有机质,尤其是其中的非烃和沥青质是东部凹陷过渡带气最主要的母源物质。  相似文献   

11.
High hydrogen pressure pyrolysis (hydropyrolysis) was performed on samples of solvent extracted Kimmeridge Clay Formation source rock with a maturity equivalent to ca. 0.35% vitrinite reflectance. We describe the types and distributions of organic nitrogen compounds in the pyrolysis products (hydropyrolysates) using GC-MS. Compounds identified included alkyl-substituted indoles, carbazoles, benzocarbazoles, quinolines and benzoquinolines. The distributions of the isomers of methylcarbazoles, C2-alkylcarbazoles and benzocarbazoles in the hydropyrolysates were compared to a typical North Sea oil. The hydropyrolysates compared to the North Sea oil, showed increased contributions from alkylcarbazole isomers where the nitrogen group is "exposed" (no alkyl substituents adjacent to the nitrogen functionality) and appreciable levels of benzo[b]carbazole relative to benzo[a]- and benzo[c]carbazoles. Hydropyrolysis is found to be an ideal technique for liberating appreciable quantities of heterocyclic organic nitrogen compounds from geomacromolecules. The products released from the immature Kimmeridge Clay are thought to represent a potential source of nitrogen compounds in the bound phase (kerogen) able to contribute to the free bitumen phase during catagenesis.  相似文献   

12.
A wildcat may not result in a petroleum prospect; however, it may indicate potential need for frontier exploration, since petroleum could leak into economic accumulations. Carbazoles and benzocarbazoles are nitrogen compounds in petroleum and can be employed to explicitly explain migration direction and distance of leaking petroleum. The hypothesis of this study is that the mechanism of the reaction involving the attraction of carbazoles to clay minerals on the matrix of the walls along their migration pathways determines the isomer that is preferentially attached to the mineral matrix. The objectives of this study are (a) to produce a profile for carbazoles and benzocarbazoles ratios in the cap rock overlying the reservoir, (b) to compare carbazole and benzocarbazole ratios to 20S/(20S + 20R) αααC29 Sterane maturity ratios (c) to infer migration direction from the carbazoles and benzocarbazoles ratio. Samples used were side wall cores and drill cuttings of water-based mud drilling. The EOM (extractable organic matter) from various formations overlying the reservoir was obtained using Soxtherm Automatic Equipment. The TPH (total petroleum hydrocarbon) was obtained from the EOM by using a precleaned isolute C18 500 mg / 3 mL column, eluted with hexane, while the polars were eluted with dichloromethane. Fractionation into saturates and aromatics was done using a silver nitrate–silica gel column. The profiles of 1,8/1,3 and 1,8/2,4 dimethyl carbazoles and the benzocarbazoles ratios show a vertical gradient of decreasing ratio with increasing vertical distance from the reservoir. This corroborates the %VRo equivalent of 20S/(20S + 20R) αααC29 Sterane and the carbazole ratios infer vertical migration of leaked petroleum.  相似文献   

13.
The distance between 4-H and adjacent H on the substitutional benzene ring in benzo[c]carbazole was calculated in terms of molecular structure parameters. The result showed that the distance is shorter than the sum of van der Vaals' radii of two hydrogen atoms. This means that there is a steric hinderance between them. This effect will make the bond angle stretch and the bond length extend, or cause the molecule to distort, thus making benzo[c]carbazoles become unstable in thermodynamics. On the contrary there is no such effect for benzo[a]carbazoles. This conclusion has been confirmed by the result of calculation of the distance between the same two atoms with software GaussView. So the skeleton of benzo[c]carbazoles in sediments may be breached or isomerized with increasing maturity. It is consistent with the decrease of the ratio of benzo[c]carbazole to benzo[a]carbazole in hydrocarbon migration, suggesting that [c]/[a] not only changes with the distance of migration, but also may be influenced by maturity.  相似文献   

14.
Carbazole, its alkyl derivatives and higher benzologs have been selectively isolated from six different crude oils. In all samples, benzocarbazoles are major constituents of a series which may extend up to dibenzocarbazole derivatives. The distribution includes unsubstituted parent compounds and shows a maximum content of methyl and dimethyl substituted species. Sixteen individual constituents have been identified by means of comparison with reference compounds using gas chromatography, mass spectrometry and high resolution spectrofluorimetry. So far, no generally acceptable explanation has been given for the origin of these compounds, which presumably are the most stable ones in their respective series of aromaticity. Thus, carbazole derivatives may result from a complex sequence of reactions during kerogen formation, not allowing the recognition of precursing molecules. The geochemical significance of this series of nitrogen compounds needs to be clarified, requiring further studies.  相似文献   

15.
低熟油、烃源岩中含氮化合物分布规律及其地球化学意义   总被引:18,自引:3,他引:18  
对八面河地区原油、油砂以及不同成熟度和岩性有异的烃源岩中吡咯类化俣物的分布特征及其潜在的地球化学意义进行了探讨。结果表明,随着成熟度的增加,八面河地区烃源岩中吡咯类化合物中屏蔽化程度高的异构体比屏蔽化程度低的异构体富集,咔唑及苯并咔唑系列中低相对分子质量的同系物比高相对分子质量的同系物富集,苯并[a]咔唑比苯并[c]咔唑富集。八面河地区原油中吡咯类化合物有较为明显的运移分馏效应,观察到高、低相对分子质量的同系物间的运移分馏效应比不同类型异构体间的分馏效应更为显著,而前者受成熟度的影响可能相对小于后者;发现吡咯类化合物的油气运移分馏效应不仅体现于不同氮官能团屏蔽、半屏蔽和暴露三类异构体间,同样体现于同一类型的同分导师构体之间,指示此类化合物有较强的活性。吡咯类化俣物与烃类化合物一样具有多方面潜在的地球化学意义。  相似文献   

16.
胡庆油田湖相原油咔唑类化合物的地球化学特征   总被引:1,自引:0,他引:1  
胡庆油田湖相原油成熟度低,多为低成熟原油,生物降解作用轻微,原油中含有丰富的咔唑类化合物。分析表明,原油成熟度对咔唑类化合物含量及相对组分影响明显,源岩沉积环境对其也有一定的影响,而生物降解作用对咔唑类化合物含量及相对组分影响很小。原油中咔唑类化合物含量、链基咔唑/苯并咔唑及苯并咔唑比值受原油成熟度与沉积环境影响明显,已不适合用来指示油气运移距离,而二甲基咔唑同分异构体比值所受影响小,仍可作为油气运移的有效参数。  相似文献   

17.
<正>Kailu Basin in which the Western Lujiapu Depression is located is a typical continental rift basin.Biomarker parameters of the oils indicate that depositional facies and environments vary between the Bao 1 and Bao 14 fault blocks with a higher saline environment in the Bao 1 fault block, but such difference has no significant impact on carbazole abundance and distribution.Maturity and migration distance are the main controls on carbazole abundance and distribution in the Western Lujiapu Depression.The commonly used migration indices,such as ratios of nitrogen shield isomers to nitrogen exposed isomers(1-/4-methylcarbazole ratio,1,8-/2,4-dimethylcarbazole(DMC) ratio and half-shield/exposed-DMC ratio),absolute concentrations of alkylated carbazoles and BC ratio(=benzo [a]carbazole/(benzo[a]carbazole+benzo[c]carbazole)) increase at the low mature range and decrease at a higher mature range with increasing maturity.At relatively low maturity stage(Rc0.77%), maturation has reversal effects with migration on the ratios of nitrogen shield isomers to nitrogen exposed isomers,which may cover migration influence and makes these parameters fail to indicate migration effects.Valid migration indicators at this maturity stage are concentrations of alkylated carbazoles and BC ratios,which can provide ideal tools for migration direction assessment even within short migration distance.Maturity effects should be taken into account when carbazole compounds are applied to indicate migration direction,and at different maturity stages,these commonly used parameters have different validity in tracing migration direction.Coupled with our previous study in the Eastern Lujiapu Depression,a conceptual model of the variation of nitrogen migration indices can be established for terrestrial rifted basins,that is,strong fractionation lateral migration model through sandy beds,weak fractionation vertical migration model along faults,and maturity impacts on migration assessment.  相似文献   

18.
Hydrous pyrolysis experiments were performed on the Ghareb Formation (Upper Cretaceous, Jordan), a carbonate- and organic-rich (TOC 19.6%) source rock, using a temperature range of 200 to 360°C (72 h). The original sediment contains only low amounts of carbazoles, (maximum 2.2 μg/g bitumen for 1-methylcarbazole). With increasing thermal maturation, intense generation begins at temperatures only in excess of 300°C, reaching a maximum at 360°C. Likewise, during natural maturation, generation occurs at later stages of maturity (e.g. for Tithonian source rocks at >0.81% Rr and for Posidonia Shale at >0.88% Rr). Some isomeric changes during hydrous pyrolysis do not resemble those in nature whereas others do. The relative abundances of selected C1- and C2-alkylcarbazoles on ternary diagrams reveal differences, whereas the benzo[a]carbazole/benzo[a]carbazole+benzo[c]carbazole ratio is closely similar. The latter result supports the contention that maturation plays a key role in controlling carbazole distributions in source rocks. However, the results for alkylcarbazoles, especially the C2-carbazoles, are not easy to interpret.  相似文献   

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