Organic petrology and source rock potential of sediments in the Eromanga Basin, South Australia

Cuttings and cores from the Poolowanna 1 well, Eromanga Basin, South Australia (in which oil was discovered in Lower Jurassic reservoirs) and the Macumba 1 well (no oil) have been analyzed petrographically to assess the nature of the coals and dispersed organic matter present. The Jurassic and Cretaceous coals have medium to high vitrinite contents, low to relatively high exinite, and medium to low inertinite contents. The dispersed organic matter has comparatively less vitrinite, more exinite and/or more inertinite than the associated coals. The microlithotype compositions of the coals indicate that the original vegetation was largely woody in character and was buried before much oxidation had occurred.The Jurassic sediments contain up to 2% dispersed organic matter by volume, 0–75% of which is exinite, including alginite. Vitrinite reflectances range from 0.5 to 0.7%. Where sufficiently mature, the Jurassic sediments are good potential source rocks for hydrocarbons.Statistical testing of the analytical results for the Jurassic Poolowanna Formation using Kendall's τ as a measure of dependence shows that there is a significant association between the macerals in coal and dispersed organic matter. The ratio of exinite to inertinite in dispersed organic matter is reasonably well predicted by the corresponding ratio in the associated coal.     

http://www.sciencedirect.com/science/article/pii/S1674987111000879

Multiple sets of thick coal beds characterized by simple structure and shallow burial depth were developed in the Early and Middle Jurassic strata of the Ordos Basin,northwestern China.The huge reserves of this high quality coal have a high commercial value.We studied the coal’s petrologic characteristics and its maceral distribution to determine the maceral’s contribution to generation of oil and gas.The results show that the Jurassic coals in the Ordos Basin have special penological features because of the Basin’s unique depositional environment which was mainly a series of high-stand swamps in the upper fluvial system.These petrographic features are a result of the development of typical inland lakes where some sand bodies were formed by migrating rivers.After burial,the peat continued to undergo oxidizing conditions,this process generated extensive higher inertinile contents in the coals and the vitrinite components were altered to semi-vitrinite.The macroscopic petrographic types of these Jurassic coals are mainly semi-dull coal,dull coal,semilustrous and lustrous coal.The proportions of semi-dull coal and dull coal are higher in the basin margins,especially in the area near the northern margin.The numbers of semilustrous and lustrous coals increase southwards and towards the central basin.This situation indicates that different coal-forming swamp environments have major controlling effects on the coal components.Another observation is that in the Ordos" coal sequences,especially in the lower part,some sandstone beds are thick,up to 20 m with a coarse grain size.The higher fusinite content in the macerals accompanies a higher semi-vitrinite content with more complete and regular plant cell structure.The fusinite structure is clear and well preserved.After burial,the lithology of the roof and floor rocks can continue to affect the evolution of coal petrology.The sand bodies in the roof and floor exhibit good physical conditions so that pore water can maintain a long-term state of oxidation,circulation and connection to the coal.So coal components remain in an oxidation environment for a long time.Conversely,in the basin center,lacustrine facies developed and peat was rapidly covered by mudstone after burial and subsequent coal beds rapidly entered a reducing environment.As a result,abundant gelatification occurred and the vitrinite content increased.Exinite often accumulated in a specific position in the coal bed.Although the average exinite content is not high on the whole,it does significantly contribute to the total hydrocarbon generation. The exinite content has been underestimated,especially the amorphous bituminous fluid and its importance is emphasized here.The reason is that the fluid flows easily into fusinite which has strong rigidity,or flows into some fissures,where it is commonly neglected.     

煤炭显微煤岩组分与工业分析关系研究

通过分析宁夏各煤田中部分具有代表性煤矿勘查阶段钻孔煤岩煤样测试数据,研究了煤的显微煤岩组分与工业分析之间的关系。随着煤中有机组分、无机组分含量的变化,煤的灰分、挥发分、固定碳发生变化。煤中有机组分含量大于90%时,煤中灰分与黏土类含量存在正相关,挥发分与惰质组和壳质组含量均存在正相关,且惰质组含量影响更大;有机组分含量小于90%时,煤中灰分与惰质组和黏土类含量均存在正相关,且惰质组含量影响更大,挥发分与壳质组含量存在正相关。煤中固定碳含量受镜质组含量影响最大,二者存在正相关。     

从各向异性壳质组的发现论壳质组在煤化过程中的光性演变

通过对我国几个典型煤田300多块煤光片的详细煤岩研究,发现煤中存在一种高反射具强烈各向异性的有机显微组分,有些保存了完好的壳质组外形和结构.可称之为各向异性壳质组,它广泛分布于长焰煤以上各煤级煤中,它的发现进一步说明了壳质组的煤化历程是复杂的。有些在煤化过程中几乎全部裂解为烃类而消失,绝大多数光性与共生镜质组同化,还有一少部分转变成了各向异性壳质组。     

河北南部石炭一二叠纪煤层气烃源岩特征

河北南部地区石炭一二叠系煤层煤种丰富,峰峰、邯郸矿区煤层的宏观煤岩类型以半亮煤和半暗煤为主;显微煤岩类型为微镜煤、微镜惰煤及微暗煤;煤的结构以细、中宽条带状结构为主,在半亮煤和半暗煤中最多;有机显微组分以镜质组最高,一般可占50％～91％,惰质组占10％～35％,壳质组含量一般不超过5％,对煤层气来说,这是比较有利的烃源条件：区内大淑村矿2煤的矿物质含量最低,其煤的吸附能力较其它矿区高;主煤层镜质组最大反射率具有北高南低的分布规律,揭示了煤的生烃强度具有由南向北逐渐增高的趋势。该区煤层气源岩不仅影响煤的生烃能力,还影响着煤层对甲烷的吸附能力和煤层气的开采能力。     

Carbon-13 NMR spectra of macerals separated from individual coals

The density gradient centrifugation technique has recently been applied to the separation of macerals from whole coals. Sufficient quantities have been separated to permit examination of pure exinite, vitrinite and inertinite fractions by combined cross polarization and magic angle sample spinning (CP/MASS) carbon-13 NMR techniques. The similarities and differences observed in the maceral groups of two coals are discussed. Diversity in precursors or in differential chemical maturation or a combination of both of these factors can be used to account for subtle spectral differences in the two coals and macerals studied even though the gross spectral features are very similar for a given maceral type. The data show that CP/MASS is a technique that can address such interesting geochemical questions.     

PHYSICAL AND CHEMICAL PROPERTIES OF BITUMINOUS COAL CONSTITUENTS (MACERALS)

Investigation of bituminous-coal macerals, accomplished through the Institut für Brennstoff Chemie (Fuel Chemistry Institute) of Aachen, is summarized here. Coal from five Ruhr coal beds was processed to obtain pure macerals in quantities sufficient to study their individual structure and chemical composition. Vitrinite, micrinite and exinite were recovered accordingly, and their chemical and physical properties studied; detailed, graphical interpretation of these data has been included. Chemical composition is derived for vitrinite, exinite, micrinite, and fusinite individually. Chemical structure of the macerals is discussed in relation to aromatically bound carbon content. It has been possible thus far, to determine maceral properties with respect to coalification rank as well as to indicate differentiation of these properties in macerals from the same coal bed. --D. D. Fisher.     

Coal as a source rock for oil: a review

The geological debate about whether, and to what extent, humic coals have sourced oil is likely to continue for some time, despite some important advances in our knowledge of the processes involved. It is clear that not only liptinites, but also perhydrous vitrinites have the potential to generate hydrocarbon liquids in the course of natural coalification. Some liptinites, especially alginite, cutinite, and suberinite, contain a higher proportion of aliphatic moieties in their structure than other liptinites such as sporinite and resinite and are, therefore, more oil-prone. It is of potential value to be able to predict the several environments of deposition in which coals with high liptinite contents or containing perhydrous vitrinites may have been formed. Review of the distribution of oil-prone coals in time and space reveals that most are Jurassic–Tertiary with key examples from Australia, New Zealand, and Indonesia. Methods based both on experimental simulations and the examination of naturally matured samples have been used to determine the order of generation of hydrocarbons from different macerals. Results are not entirely consistent among the different approaches, and there is much overlap in the ranges of degradation, but it seems probable that in the natural environment vitrinites begin to generate early, followed by labile liptinites such as suberinite, then cutinite, sporinite, and, finally, alginite.Petroleum potential may be determined by experimental simulation of natural coalification or inferred through various micro-techniques, especially fluorescence and infrared (IR) spectroscopy, or bulk techniques such as elemental analysis and ¹³C NMR spectroscopy. The latter three techniques enable a measure of the polymethylene component of the coal, which now appears to be one of the best available approaches for determining petroleum potential. No method of experimental simulation of petroleum generation from coals is without criticism, and comparative results are highly variable. However, hydrous pyrolysis, confined pyrolysis, and forms of open-system hydrous pyrolysis approach acceptable simulations.Whether, and to what degree generated liquid hydrocarbons are expelled, has long been the central problem in ‘oil from coal’ studies. The structure of vitrinite was believed until recently to contain an interconnected microporous network in which generated oil would be contained until an expulsion threshold was attained. Recent studies show the pores are not interconnected. Combined with a dynamic model of pore generation, it now seems that expulsion of hydrocarbons is best explained by activated diffusion of molecules to maceral boundaries and ultimately by cleats and fractures to coal seam boundaries. The main reason for poor expulsion is the adsorption of oil on the organic macromolecule, which may be overcome (1) if coals are thin and interbedded with clastic sediments, or (2) if the coals are very hydrogen-rich and generate large quantities of oil.The existence of oil in vitrinite is attested to by solvent extractions, fluorescence properties, and by microscopic observations of oil and bitumen. Experimental simulation of expulsion of oil from coals has only recently been attempted. The relative timing of release of generated CO₂ and CH₄ could have considerable importance in promoting the expulsion of liquid hydrocarbons but the mechanism is unclear. As it is universally agreed that dispersed organic matter (DOM) in some shales readily generates and expels petroleum, it is curious that few consistent geochemical differences have been found between coal macerals and DOM in interbedded shales.Unambiguous evidence of expulsion from coals is limited, and in particular only a few commercial oil discoveries can be confidently correlated to coals. These include Upper Cretaceous Fruitland Formation coals in the USA, from which oil is produced; New Zealand Tertiary coals; and Middle Jurassic coals from the Danish North Sea. It is likely that coals have at least contributed to significant oil discoveries in the Gippsland Basin, Australia; in the Turpan Basin, China; and in the Kutei and Ardjuna basins in Indonesia, but this remains unproven. Early reports that early Jurassic coals in mid-Norway were a major source of the reservoired oils have been shown to be inaccurate.None of the proposed ‘rules of thumb’ for generation or expulsion of petroleum from coals seem particularly robust. Decisions on whether a particular coal is likely to have been an active source for oil should consider all available geological and geochemical information. The assumptions made in computational models should be well understood as it is likely with new understandings of processes involved that some of these assumptions will be difficult to sustain.     

Geochemical Characteristics and Sedimentary Control of Pinghu Formation (Eocene) Coal‐bearing Source Rocks in Xihu Depression,East China Sea Basin

Coal-bearing source rocks of the Pinghu Formation in the Xihu Depression comprise an important material basis of oil and gas resources in the East China Sea Basin.Based on drilling core observation results combined with the analysis and test results of macerals,trace/rare earth elements,and rock pyrolysis,the geochemical characteristics and sedimentary control of coal-bearing source rocks formation are discussed in a high-frequency sequence framework.The results indicate that the macerals composition of the coal-bearing source rocks of the Eocene Pinghu Formation in the Xihu Depression is dominated by vitrinite,with low-medium abundance of exinite and almost no inertinite.The coals and carbonaceous mudstones display higher amounts of total organic carbon(TOC)(14.90%-65.10%),S1+S2(39.24-136.52 mg/g),and IH(191-310 HC/g TOC)respectively,as compared to the mudstones.Organic matter is plotted in typeⅢkerogens and partially in typeⅡ;it is mainly in the low maturity stage.The trace elements results imply that the samples were deposited in a weakly reducing to weakly oxidizing environment and were occasionally affected by seawater.The coal-bearing source rocks were deposited in a relatively oxygen-containing environment.The coal-bearing source rocks development is jointly controlled by the coal accumulation environment,the water conditions affected by ocean currents in offshore basins in China,oxidation-reduction cycles of aqueous media and paleoclimate evolution in a high-frequency sequence framework.     

Characteristics of hydrocarbon generation from organic macerals in Jurassic coal measures, Xinjiang, China

The Jurassic coals of the Junggar and Turpan-Hami basins, Xinjiang, China, are characterized by abundant vitrinite. Microscopic analysis of Junggar coal samples indicates that they contain desmocollinite and hydrogen-rich vitrinite with a low reflectivity. The hydrocarbon-generating potential of various macerais follows the decreasing order of exinite > vitrinite > inertinite. However, desmocollinite is a principal maceral for hydrocarbon generation in this area because the content of vitrinite is higher than that of exinite. Data from simulating experiments and infrared spectra show that the hydrocarbon-generating process occurred primarily at the lower-mature stage in the Middle-Lower Jurassic coal measures. Generally, crude oil from the Qigu oilfield has a close similarity in hopanoid distribution to the vitrinite and exinite from the Jurassic strata with C₂₃-C₃₂ pentacyclic triterpanes and γ-lupane being present. The distribution of steranes is also similar. C₂₉-sitostane is dominant and Q₂₇ ergostane is subordinate. Only a trace amount of cholestane is present. All this suggests that the crude oil from the Qigu oilfield was derived from Jurassic coal measures.     

Partitioning of elements and macerals during preparation of Antaibao coal

Analyses of the macerals, ash, sulfur and 43 major and trace elements were performed on samples of feed coal, cleaned coal, middlings and slime collected from the Antaibao coal preparation plant, China, and also on samples from coal preparation experiments. This study is focused on the partitioning of elements and macerals during coal preparation and potential environment aspects of the elements.The conclusions are as follows: (1) in comparison with the feed coal, the cleaned coal has a higher vitrinite content and relatively lower inertinite and exinite contents, whereas the middlings and slime have lower vitrinite and exinite contents, and relatively higher inertinite contents. The vitrinite contents in the size-segregated cleaned coals were observed to show a slightly increasing tendency with increasing particle size, while the inertinite contents decreased. (2) Physical coal cleaning is not only effective for removal of ash and sulfur, but also in reducing the concentration of most elements. As, Cd, Co, Cs, Hg, Fe, K, Mg, Nb and Ni are observed to show a high degree of removal, while Br, Be, Cu, U, Mn, Zn and organic sulfur are enriched in the cleaned coal and show a lower degree of removal. The large-sized cleaned coal is cleaner than the smaller sized fractions. (3) The middlings, especially the slime, are enriched in S, Hg, Cr, V, Zn, etc., so that these fractions should not be directly used as fuel. In addition, the concentration of Pb and V in the process water exceeds the limit of relevant environmental water quality standard. Consequently, it is necessary to develop new processes to remove ash, sulfur and hazardous trace elements to the maximum extent. Further studies on deep processing of the middlings and slime and cleaning of the process water should also be performed.     

The petrology of greek brown coals

Results are given in the petrography of Greek coals collected from most of the major coal-bearing basins in Greece.Rank was determined by measuring reflectances on the maceral varieties eu-ulminite A and eu-ulminite B and on the maceral textinite. Reflectances obtained from these components indicate a coalification stage of brown coal for all samples. Within this group of samples there is, however, a fairly wide scatter of reflectance values indicating for some of them the transition zone from peat to brown coal and for others a coalification stage close to the transition into bituminous coals. Reflectances obtained from eu-ulminite A and eu-ulminite B were found to correlate well with chemical rank parameters such as volatile matter and calorific value.Composition was determined by maceral analysis. The coals are in general characterized by low amounts of macerals of the inertinite group, low to intermediate amounts of macerals of the liptinite group and high amounts of macerals of the huminite group. Within the latter group densinite, attrinite, eu-ulminite and textinite make up the bulk of the samples.Typical macerals observed in the coals are illustrated by two black and white and three colour plates.Cluster analysis based on maceral distribution, mineral matter and reflectance indicates that the samples studied can be divided into three major groups. The first one is dominated by eu-ulminite and densinite with relatively high reflectances. The second is dominated by attrinite, textinite and texto-ulminite with somewhat lower reflectances. The third is represented by a single sample in which textinite and resinite are the most abundant macerals. This sample also has the lowest reflectance.     

Delineation of the distinctive nature of tertiary coal beds

Floral character in mires has changed progressively through time. In the Carboniferous, pteridophytes, sphenophytes and lycophytes were dominant but by the Permian gymnosperms were an important component of mire flora. During the early Mesozoic gymnosperms remained the characteristic mire vegetation, together with pteridophytes, and conifers became dominant during the Jurassic. Cretaceous and Paleocene vegetation are similar, with taxodiaceous flora being important in mire vegetation. From the Eocene onwards, however, angiosperms were increasingly dominant in mire communities and in the Miocene herbaceous vegetation began to play a significant role. Together with these changes in floral character at least three aspects of coal character also appear to vary sequentially with time and are distinctive in the Tertiary: (1) proportions and thickness of vitrain banding, (2) coal bed thickness and (3) proportions of carbonised material. A compilation has been made of data from the coal literature comparing older coals with those of the Tertiary, in order to give a perspective in which to examine Tertiary coals. It was found that only Tertiary coals contain significant proportions of coal devoid of vitrain bands. In addition, Tertiary coals are the thickest recorded coal beds and generally contain low percentages of carbonised material (many less than 5%) as compared to older coals. It is interesting to note that Paleocene coal beds are similar to Cretaceous coals in that they tend to be thinner and contain higher proportions of carbonised material than do younger Tertiary coals.The absence of vitrain bands in some Tertiary coal beds is thought to result from the floras dominated by angiosperms, which are relatively easily degraded as compared to gymnosperms. The thickness of Tertiary coals may be related to an increase in biomass production from the Carboniferous through to the Tertiary, as plants made less investment in producing lignin, an energy-intensive process. In addition, with less lignin in plants, easier degradation of biomass may have facilitated nutrient recycling which, in turn, led to greater biomass production. Increased biomass production may have also ‘diluted’ the carbonised material present in some Tertiary peats, leading to lower proportions in the coal. Another possible cause of decreased carbonised components in Tertiary coal is that decreasing lignin content resulted in decreased charring during fires, as lignin is particularly prone to charring. A third possibility is that the carbonised component of peat may be concentrated during coalification so that Tertiary coals, generally of lower rank than Mesozoic or Paleozoic coals, contain a smaller fraction of carbonised plant material. It is not at present clear which of these mechanisms may have affected carbonised material in peat and coal but it is clear that lignin type and content has had an important role in determining peat and coal character since the Paleozoic.     

神府大柳塔2~(-2)煤层煤岩学特征

对神府大柳塔矿区 2 - 2煤层系统的煤岩学研究表明 ,该煤层以镜质体和丝质体为主 ,其它组分较少 ,矿物质中以粘土类和石英为主 ,显微煤岩类型以两组分微类型为主 ,宏观煤岩类型以半暗煤和半亮煤为主 ,壳质组具有较强的荧光 ,其荧光光谱为单峰形 ,不同的壳质组分其荧光特征不同     

西北地区侏罗纪煤系烃源岩和油气地球化学特征

阿尔金断裂以北的新疆地区煤系泥岩和煤均很发育,而以南的甘青宁地区湖相和沼泽相泥岩发育。煤系烃源岩中主要的成烃显微组分是壳质体、藻类体、基质镜质体等,有机质类型以Ⅲ型为主;煤系泥岩一般为中到差油源岩,少数为好烃源岩,煤一般为差油源岩,下侏罗统源岩生烃潜力高于中侏罗统源岩;煤系原油一般为成熟的轻质、中蜡、低凝固点、低硫优质原油;油源对比表明煤系泥岩是主要烃源岩,煤和碳质泥岩是次要烃源岩;有利生油区域基本分布在侏罗纪的沉降沉积中心,而且后续埋藏又较深的山前坳陷区域。     

瓦窑堡煤系有机岩石学特征及煤成烃潜力研究

瓦窑堡煤系是我国重要的含煤岩系之一,陆相生油的观点最早可能源于瓦窑堡煤系含油性特征。通过对瓦窑堡煤系煤和暗色泥岩有机质的显微岩石学和宏观煤岩学特征的分析,提出了瓦窑堡煤系煤主要形成于深覆水森林泥炭沼泽相,类脂组含量高,且镜质组的主要类型为富氢的基质镜质体,有机地球化学结果表明瓦窑堡煤系煤具有Ⅱ型有机质的特征,处于低熟-成熟阶段,热模拟实验证明其具有良好的油气生成潜力。但由于瓦窑堡煤系规模小,煤层厚度薄,煤系泥岩有机质类型偏差,且煤中主要生油显微组分尚末进入大量生油期,因此难以形成油藏。     

鄂尔多斯盆地延安组煤有机岩石学研究

鄂尔多斯盆地侏罗纪延安组煤系地层可否成为该盆地另一套油源岩的问题,历来存有争议。系统的煤岩和有机岩石学分析表明:煤中倾油性的壳质组分含量低,基质镜质体的类型也不利于生油,因此,延安组煤系有机质不大可能形成具有工业价值的煤成油藏     

淮北矿区芦岭煤矿构造煤发育特征

淮北矿区芦岭煤矿主采煤层8煤为特厚煤层,厚度2．72-17．75m,平均厚度9．60m,煤层硬度系数厂为0．16-0．53,构造煤累计厚度约占全层厚度的65％-90％。剖面自上而下划分为碎裂煤、菱形包裹体煤、片状煤、鳞片煤和粉末状煤5种类型,构造类型煤相间分布。微观上网络状裂隙发育．密集的网络状裂隙交叉切割．显微组分破坏严重．煤层受构造作用影响越大,构造煤中的微孔所占比例也就越高。在平面上构造煤的发育可划分为东、中、西三部分,井田东部构造煤较发育,厚度占全层厚度的75％-80％;中部构造煤最发育,厚度占全层厚度的95％以上;井田西部构造煤所占比例相对较低,约占全层厚度的65％-70％。采区资料表明,在倾向上,随着煤层深度的增加,构造煤厚度占金层厚度比例呈上升趋势．-450--460m水平以下,构造煤层所占比例明显增高,约占95％以上。     

Coal mine workers' pneumoconiosis

 The fibrogenic and cytotoxic potential of coal mine dust is independent of the amount of quartz and other inorganic parameters. Results of coal petrographical and organic geochemical investigations of coals and coal mine dust from the Ruhr and Ibbenbüren Region of Germany demonstrate variations of organic dust amount possibly influencing these noxious properties. Coal mine dust of high rank coals is characterized by a pronounced fibrogenic risk. This risk, independent of the quantity of quartz, is probably based on shape variations of different coal macerals. With increasing coalification of the corresponding seam, the vitrinite is enriched in its dust; however, lower concentrations have been determined for inertinite. Vitrinite shows constant shapes and sizes independent of the rank of coal. Inertinite particles with elongated to fibrous shapes tend to larger sizes with increasing coalification. Strikingly, coal mine dust from miners' lungs with high degrees of coal mine workers' pneumoconiosis (CWP) is enriched in inertinite. In contrast, high cytotoxicities in cell tests are known for coal mine dust from low coalified coals. High concentrations of phenolic compounds can be extracted by dichloromethane from low coalified coal mine dust. These compounds, which are characterized by a high water solubility and therefore high bioavailability, explain the high cytotoxicities of coal mine dust. Contamination of dust by diesel emissions in the coal mine can act as additionally supporting parameters for extended cytotoxicities. Received: 18 August 1995 · Accepted: 15 October 1995     

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

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。