This paper mainly use fine-grained silica gel to separate saturated and aromatic hydrocarbon in oil or extraction.By experiment,the method can separate saturated and aromatic hydrocarbon completely.Isomeric hydrocarbon increased in saturated hydrocarbon,alkylbenzenes and monoaromatic steranes group are also entered into aromatic hydrocarbon completely.The method makes up the deficiency in common method to separate saturated and aromatic hydrocarbon.In order to verify the reliability of the experiment,the author made a precision experiment at the same time,the error no more than 5%,This proved that the experimental apparatus is stable and the results is credible.

The light hydrocarbons of oils play an important role in their geochemistry, especially in mixed oils. The database of the Key Laboratory of Petroleum Geochemistry, China National Petroleum Corporation has accumulated 824 oil sample records. The oil samples represent most of the oil areas of China. In this paper the light hydrocarbons of salt lake derived oils from Jianghan basin, China, were studied. These oils are characterized by high toluene contents and high K1 [K1=(2-MH+2,3-DMP)/(3-MH+2,4-DMP)] values. The reason is unclear but may be related to the high salinity environment of the source.

A series of isothermal hydrous pyrolysis experiments was performed on immature sedimentary rocks and peats of different lithology and organic source input to explore the generation of diamondoids during the thermal maturation of sediments. Oil generation curves indicate that peak oil yields occur between 340 and 360°C, followed by intense oil cracking in different samples. The biomarker maturity parameters appear to be insensitive to thermal maturation as most of the isomerization ratios of molecular biomarkers in the pyrolysates have reached their equilibrium values. Diamondoids are absent from immature peat extracts, but exist in immature sedimentary rocks in various amounts. This implies that they are not products of biosynthesis and that they may be generated during diagenesis, not just catagenesis and cracking. Most importantly, the concentrations of diamondoids are observed to increase with thermal stress, suggesting that they can be used as a molecular proxy for thermal maturity of source rocks and crude oils. Their abundance is most sensitive to thermal exposure above temperatures of 360–370°C (R0=1.3–1.5%) for the studied samples, which corresponds to the onset of intense cracking of other less stable components. Below these temperatures, diamondoids increase gradually due to competing processes of generation and dilution. Calibrations were developed between their concentrations and measured vitrinite reflectance through hydrous pyrolysis maturation of different types of rocks and peats. The geochemical models obtained from these methods may provide an alterative approach for determining thermal maturity of source rocks and crude oils, particularly in mature to highly mature Paleozoic carbonates. In addition, the extent of oil cracking was quantified using the concentrations of diamondoids in hydrous pyrolysates of rocks and peats, verifying that these hydrocarbons are valuable indicators of oil cracking in nature.

To judge the direction of petroleum secondary migration by using geochemical parameters,the simulation experiment of secondary oil migration was performed in self-designed apparatus.The family composition,saturated hydrocarbons,aromatic hydrocarbons,and alkyl phenol and neutral nitrogen compounds in the simulation samples were analyzed using GC-MS.The results demonstrate that crude oils have the same phenomena as the chromatography process while passing through carrier beds.In the experiment,except for the light fraction which is mainly used for solvent,all other compound contents do not simply increase or decrease,instead they have an enriching process.The migration direction can be judged by combining the concentration curve of the compounds and their ratio curve into one drawing.If both the curves change in one direction(increase or decrease),the direction is the migration direction.If they have different directions,then the decrease direction is the migration direction of crude oils.

It is difficult to identify the source(s) of mixed oils from multiple source rocks, and in particular the relative contribution of each source rock. Artificial mixing experiments using typical crude oils and ratios of different biomarkers show that the relative contribution changes are non-linear when two oils with different concentrations of biomarkers mix with each other. This may result in an incorrect conclusion if ratios of biomarkers and a simple binary linear equation are used to calculate the contribution proportion of each end-member to the mixed oil. The changes of biomarker ratios with the mixing proportion of end-member oils in the trinal mixing model are more complex than in the binary mixing model. When four or more oils mix, the contribution proportion of each end-member oil to the mixed oil cannot be calculated using biomarker ratios and a simple formula. Artificial mixing experiments on typical oils reveal that the absolute concentrations of biomarkers in the mixed oil cause a linear change with mixing proportion of each end-member. Mathematical inferences verify such linear changes. Some of the mathematical calculation methods using the absolute concentrations or ratios of biomarkers to quantitatively determine the proportion of each end-member in the mixed oils are deduced from the results of artificial experiments and by theoretical inference. Ratio of two biomarker compounds changes as a hyperbola with the mixing proportion in the binary mixing model, as a hyperboloid in the trinal mixing model, and as a hypersurface when mixing more than three end-members. The mixing proportion of each end-member can be quantitatively determined with these mathematical models, using the absolute concentrations and the ratios of biomarkers. The mathematical calculation model is more economical, convenient, accurate and reliable than conventional artificial mixing methods.

通过大量烃标样拉曼分析发现:饱和烃以甲基、亚甲基在2700~2970cm?1区域有强烈的拉曼谱峰为特征;异构骨架在748cm?1处有一强的拉曼效应;环六环在804cm?1处有一个强的拉曼效应;苯环有二个拉曼特征峰(988,3058cm?1±),以988cm?1±为主;己烯在1294,1635和2996cm?1±有三个烯键(C=C)拉曼特征峰,以1635cm?1±为主.论证了:(1)烃类的拉曼图与烃类的含碳个数无关,只与烃类分子结构和基团特征有关;(2)相同的烃类如正构烷烃类的拉曼光谱图相同;(3)不能简单地由烃类的特征峰来判断烃种类(如CH4,C2H6和C3H8)和某烃相对含量,尤其在混合烃类或烃类包裹体中.对比石油四大组分总的拉曼光谱图特征,将烃类包裹体的拉曼光谱图分成五种:饱和烃型拉曼光谱图、烷烃+沥青型拉曼光谱图、沥青型拉曼光谱图、荧光型拉曼光谱图、甲烷型拉曼光谱图.据烃类包裹体的拉曼光谱图特征将烃类包裹体分成五大种类:高饱和烃(气或液)烃类包裹体、含沥青饱和烃(气或液)烃类包裹体、低饱和烃(气或液)烃类包裹体、沥青质(气或液)烃类包裹体、高甲烷盐水包裹体.

The Raman spectrograms of hydrocarbon standard samples show that: (1) the Raman spectrogram of normal paraffin has very strong peaks of methyl and methylene (from 2700 cm−1 to 2970 cm−1); (2) branch methyl has the particular peak of 748 cm−1±; (3) six cyclic has the particular peak of 804 cm−1±; (4) phenyl has two particular peaks of 988 cm−1± and 3058 cm−1± and the 988 cm−1± peak is stronger than the 3058 cm−1± peak; and (5) hexene has three alkenyl spectrum peaks of 1294 cm−1±, 1635 cm−1± and 2996 cm−1±, with the 1635 cm−1± peak being the strongest, showing that the number of carbon in hydrocarbon does not affect its Raman spectrogram, and the hydrocarbon molecular structure and base groups affect its Raman spectrogram, the same hydrocarbons (such as normal paraffin) have the same Raman spectrogram; the types (such as CH4, C2H6, C3H8) and the content of hydrocarbon in oil inclusions are not estimated by their characteristic Raman peaks. According to the Raman spectrograms of hydrocarbon compositions, the Raman spectrogram of hydrocarbon inclusion can be divided into five types: saturated hydrocarbon Raman spectrogram, fluoresce Raman spectrogram, saturated hydrocarbon bitumen Raman spectrogram, bitumen Raman spectrogram, and ethane Raman spectrogram. And according to the characteristics of Raman spectrogram, hydrocarbon inclusions can be divided into five types: saturated hydrocarbon inclusion, less saturated hydrocarbon (oil or gas) inclusion, saturated hydrocarbon bitumen inclusion, bitumen inclusion, and methane water inclusion.

从褐藻门马尾藻属海黍子种(Sargassum muticum)抽提物中检出众多的△5-3β-甾烯醇类化合物,碳数分布范围,从C19～C23和C26～C30,且同一化合物的立体异构体多,最多的可达6个,这意味着低碳数甾烷可能均有各自的生源,且早在生物体内有的甾醇己存在多种的立体异构体,这对传统的甾醇类化合物在沉积成岩作用时,立体异构体转化过程的解释,提供了某些需修正或补充的实验依据.

The Raman spectrometric analysis of some standard samples of the saturated hydrocarbons has shown that there is a series of strong peaks in the Raman spectrum band of 2700~2970cm~(-1) for the saturated hydrocarbons in petroleum.They include the max-CH_3 characteristic peak(2872±cm~(-1)) for the n-alkanes,the max-CH characteristic peak(2911±cm~(-1)) for iso-alkanes and the max-CH_2 characteristic peak(2857±cm~(-1)) for cyclic alkanes.In addition,there is a peak of 748 cm~(-1) for iso-alkanes and a peak of 804 cm~(-1) for cyclic alkanes respectively.In summary,it is indicated that the hydrocarbon compounds with the same functional group show the similar distribution of Raman spectra,while the Raman peak in 2905～2921 cm~(-1) only represents the characteristic peak of-CH functional group of the hydrocarbon mixture or hydrocarbon inclusions rather than that of the CH_4.

Various Δ5-3β-sterenols, whose carbon numbers range from C19-C23 to C26-C30 and some compounds have many stereomers maximal up to six, have been detected out from the extract of brown algae (Sargassum muticum), which means that steranes with lower carbon numbers are likely different in the origin, and some corresponding sterol stereoisomers may have already existed in their precursor organisms. This provides some experimental evidence for supplementing and amending the traditional interpretation of the sterol stereoisomer transformation during the deposition and diagenesis of organic matter.

从褐藻门马尾藻属海黍子种（Sargassummuticum）抽提物中检出众多的?5-3β-甾烯醇类化合物,碳数分布范围,从C19 C 23和C26 C 30,且同一化合物的立体异构体多,最多的可达6个,这意味着低碳数甾烷可能均有各自的生源,且早在生物体内有的甾醇己存在多种的立体异构体,这对传统的甾醇类化合物在沉积成岩作用时,立体异构体转化过程的解释,提供了某些需修正或补充的实验依据.

Oil and gas exploration in eastern Tarim Basin, NW China has been successful in recent years, with several commercial gas accumulations being discovered in a thermally mature to over-mature region. The Yingnan2 (YN2) gas field, situated in the Yingnan structure of the Yingjisu Depression, produces gases that are relatively enriched in nitrogen and C2+ alkanes. The δ13C1 (−38.6‰ to −36.2‰) and δ13C2 values (−30.9‰ to −34.7‰) of these gases are characteristic of marine sourced gases with relatively high maturity levels. The distributions of biomarkers in the associated condensates suggest close affinities with the Cambrian–Lower Ordovician source rocks which, in the Yingjisu Sag, are currently over-mature (with 3–4%Ro). Burial and thermal maturity modeling results indicate that paleo-temperatures of the Cambrian–Lower Ordovician source rocks had increased from 90 to 210°C during the late Caledonian orogeny (458–438Ma), due to rapid subsidence and sediment loading. By the end of Ordovician, hydrocarbon potential in these source rocks had been largely exhausted. The homogenization temperatures of hydrocarbon fluid inclusions identified from the Jurassic reservoirs of the YN2 gas field suggest a hydrocarbon emplacement time as recent as about 10Ma, when the maturity levels of Middle–Lower Jurassic source rocks in the study area were too low (<0.7%Ro) to form a large quantity of oil and gas. The presence of abundant diamondoid hydrocarbons in the associated condensates and the relatively heavy isotopic values of the oils indicate that the gases were derived from thermal cracking of early-formed oils. Estimation from the stable carbon isotope ratios of gaseous alkanes suggests that the gases may have been formed at temperatures well above 190°C. Thus, the oil and gas accumulation history in the study area can be reconstructed as follows: (1) during the late Caledonian orogeny, the Cambrian–Lower Ordovician marine source rocks had gone through the peak oil, wet gas and dry gas generation stages, with the generated oil and gas migrating upwards along faults and fractures to form early oil and gas accumulations in the Middle–Upper Ordovician and Silurian sandstone reservoirs; (2) since the late Yanshanian orogeny, the early oil accumulations have been buried deeper and oil has undergone thermal cracking to form gas; (3) during the late Himalayan orogeny, the seals for the deep reservoirs were breached; and the gas and condensates migrated upward and eventually accumulating in the relatively shallow Jurassic reservoirs.

目前中国石油集团公司油气地球化学重点实验室原油轻烃数据库有548个中国油样的分析数据,样品基本覆盖了中国各个油区,具一定的代表性.在此基础上,选择江汉盆地(中国典型的盐湖相沉积盆地)原油轻烃的地球化学特征进行研究,它们具甲苯含量高、(2-甲基己烷+2,3-二甲基戊烷)/(3-甲基己烷+2,4-二甲基戊烷)值高的特征,推测可能与江汉盆地独特的沉积环境有关.原油轻烃中甲苯含量高和(2-甲基己烷+2,3-二甲基戊烷)/(3-甲基己烷+2,4-二甲基戊烷)值偏高的特征有望成为判别烃源岩沉积环境的地化指标之一.图4表1参14

非烃类生物标志化合物或分子标志化合物是含氧、硫、氮杂原子的有机化合物,每一个饱和烃生物标志化合物可能有多个骨架相似的含氧、硫、氮杂原子的非烃类生物标志化合物,迄今,饱和烃中常见生物标志化合物的非烃类型大都已能被识别.它们被广泛应用于石油成因理论研究和烃类生物标志物的生源研究,近十几年来,它们尚被应用于研究油藏地球化学, 原油的二次运移,古环境、古气候等领域,近年来,非烃中的生物标志化合物还有被用于油 -油对比和用键合在沥青质中生物标志化合物探索严重生物降解油油源的报道,总之,非烃地球化学应用范围不断得到扩展而日益受到重视.

渤中坳陷有东营组下段、沙河街组一段及三段等3套烃源层.如何通过地球化学特征区分沙河街组和东营组烃源岩,进而确定该区的主力烃源层,是长期困扰有关地球化学研究者的问题之一.文中对渤中坳陷及其周边陆区31块烃源岩样品和35个原油样品的饱和烃、芳烃进行了色谱-质谱分析和研究,提出用伽马蜡烷/C31升藿烷(S+R)、4-甲基甾烷/C29规则甾烷、三芳甾烷/三芳甲藻甾烷和稳定碳同位素等4个地球化学参数组合,可以有效地区分渤中坳陷的3套烃源层,并初步确定了用于判断该区混源油的3个地球化学参数的下限值.

Tumuji oil sand is located in the margin of Songliao Basin, its oil - source research is very important for this region' petroleum exploration. The GC - MS analysis has shown that Tumuji oil sand has been severely biodegraded, some terpane and sterane compounds are not used to make oil - source correlation. We have selected anti - biodegraded tricyclic terpane as the correlative parameter to make correlation with three adjacent oils. It has suggested that Tumuji oil have from Nenjian and Qingsankou soure formations. This paper has provided an effective correlation method for severely biodegraded oils.

Oil and gas exploration in eastern part of the Tarim basin was quite successful recently with several commercial gas accumulations being discoved in high to over-matured source region. Yingnan2 (YN2) gasfield, situated in Yingnan structure of the Yingjisu depression, is one representative gas accumulation. To study and gas genetic characteristics and accumulation history in this region attracts wide interests to geologists and geochemists. YN2 gases are rich in nitrogen and relatively wet. The methane and ethane stable carbon isotopic compositions are in the range of -38.6‰~-36.2‰ and (-30.9‰)~-34.7‰, respectively. They are characterized by marine source origin but more matured than variety of other marine originated oil-type gases discovered in the Tarim basin so far. Biomarkers from their associated condensates indicate closely affinity with the Lower Paleozoic Cambrian-Lower Ordovician marine source rather than the shallower Middle Jurassic coal measures. Both gas and associated condensate were obviously derived from the Cambrian-Lower Ordovician marine source in the Yingjisu depression, however, to understand and gas generation and accumulation histories remains puzzling. The Cambrian-Lower Ordovician marine source are over-matured (VRE=3%~4%) at present time and their burial and maturity evolution histories indicate that paleo-geotemperature increases rapidly from 90℃ to 210℃ within 20 Ma (458~438 Ma) during the late Caledonian period (Middle-Late Ordovician) due to rapid subsidence and quick heating, which leads source experience very short oil window (about 10 Ma) and incomplete expulsion before gas generation stage. They can be regard as dead source rocks with no and gas generation potential by the end of Ordovician. On the other hand, fluid inclusion homogenization temperature, burial and hydrocarbon generation histories suggest that YN2 gas in the Jurassic reservoir was formed within recent 10 Ma. It is not possible for the Cambrian-Lower Ordovician source to generate wet gas with dryness coefficient of 0.82~0.90 during this period, whereas the Middle Jurassic strata did not mature enough (R_O 0.7%) to form such large quantity of and gas. Such obvious discrepancy between and gas generation, accumulation histories and their properties may reflect special accumulation processes occur in this region. High concentration of diamondoid hydrocarbons detected from condensates may indicate that had experienced extensively thermal cracking. Very heavy isotopic composition in whole is a supplemental cracking evidence. Gas isotope curves illustrate that gas formation temperature is above 190℃. All these evidences suggest that gases discovered in the Tadong area are primarily form by cracking, which may turn into the vital exploration target in this region. Oil and gas accumulation processes can be reconstructed as following: the Lower Paleozoic Cambrian-Lower Ordovician marine source experienced peak-wet gas-kerogen cracking dry gas stages during the late Caledonian movement, and gas migrated upward along faults to the Middle-Upper Ordovician or Silurian sandstone reservoirs to form ancient and gas accumulations. With increasing burial depth during the late Yanshanian movement, these deep buried ancient accumulations start to cracking and large quantity of cracked gas migrates upward. Since incomplete trap development and poor tightness of top seal at this time, methane and other light components were preferentially diffusion and leaking away, leading obvious compositional fractionation in gas accumulation process and concentrated wet gas components. With trap tightness getting better and continuous gas charging in the late Himalayan movement, gases filling into the traps and leakage away through faults reach a dynamic status in certain scale, which finally forms deep sourced secondary condensate accumulations in the study area.

It is very important to select the effective correlation parameter with anti-biodegradation for calculating the contribution to biodegraded mixed oils. The results have been tested by artificial oil-mixing experiment. The biodegraded mixed oils in the PL 19-3 Oilfield, Bohai Bay, have been reconstructed using the triaromatic sterane/dinotriaromatic sterane parameter derived from typical oils from the Shahejie Formation (Member 3) and the lower Dongying Formation. From Well PL 19-3-4 (the closest to the Bozhong Depression) southward to Well 2, Well 8, and Well 5,the contribution from the source rock of the lower Dongying Formation shows a gradual decrease, from the highest value of about 30% in Well PL 19-3-4 to the lowest around 10%.

根据准东地区各油田原油的碳同位素、生物标志化合物组成特征等,可将该地区原油分为5类:第一类原油的全油碳同位素值一般小于-30‰,Pr/Ph值一般小于2.0,富含β-胡萝卜烷、三环萜烷、伽马蜡烷以及C28、C29甾烷,而C27甾烷含量很低、几乎不含重排甾烷,来源于二叠系烃源岩;第二类原油的全油碳同位素组成与第一类原油类似,但特别富含Ts、C29Ts和重排甾烷,而伽马蜡烷含量低,与三叠系烃源岩的亲缘关系很好;第三类原油的全油碳同位素明显重于第一、第二类原油,δ13C值一般大于-28‰,且Pr/Ph值一般大于3.0,富含五环萜烷和C29甾烷,而三环萜烷、伽马蜡烷、C27和C28甾烷含量低,三环萜烷中以低碳数的C19、C20三环萜烷为主,来源于侏罗系烃源岩;第四类原油地球化学特征介于上述3类原油之间,与4套已知烃源岩均没有明确的油源关系;第五类原油碳同位素特别重,δ13C值一般大于-25‰,与其它原油差异很大,来源于石炭系烃源岩.图4表1参28