准噶尔盆地车排子地区原油油源分析

车排子地区紧邻沙湾凹陷和四棵树凹陷,油源条件优越,具有多层系含油特点,前人对该区原油油源认识存在较大分歧。本次研究在研究区原油生物标志物分析基础上,结合金刚烷异构化指标和正构烷烃单体碳同位素分布,对车排子地区原油油源进行了分析。结果表明,车排子地区存在3类原油:(1)Ⅰ类原油为新近系沙湾组轻质油,表现为侏罗系来源特征, Pr/Ph比值大于2.0,原油碳同位素值偏重,δ¹³C值大于-28.0‰,姥鲛烷(Pr)、植烷(Ph)和三环萜烷含量较低, Pr/n C17和Ph/n C₁₈比值小于0.3,不含β-胡萝卜烷,三环萜烷/藿烷比值分布在0.08～0.18之间,C₂₄四环萜烷/C₂₆三环萜烷比值分布在1.61～3.81之间,ααα20R规则甾烷具有C₂₇和C₂₉规则甾烷优势,呈C₂₇>C₂₈29分布;金刚烷异构化指标I_MA值在0.30～0.38之间, I     

柯克亚凝析油气藏的油源研究

柯克亚原油成因复杂。笔者重点解剖了塔西南地区两套烃源岩侏罗系和二叠系的生物标志物特征,并厘定了区分两套烃源岩的指标,在此基础上,全面研究了柯克亚原油中生物标志物,认为柯克亚原油主要来源于二叠系烃源岩,同时原油中检测出微量的二萜类化合物,表明侏罗系烃源岩有一定的贡献。     

柯克亚原油与沙参二井原油对比及油源探讨

柯克亚原油中含γ-羽扇烷,没有C_(30,24)-丙基胆甾烷,灰份的钒/镍比值低,因而被推断为陆相原油,可能来自中下侏罗统地层。 沙参二井原油中不含γ-羽扇烷,但含有C_(30,24)-丙基胆甾烷,碳同位素值偏低,灰份中的钒/镍比值高,因而被推断为海相原油,它可能来自古生代海相碳酸盐岩地层。     

溱潼凹陷红庄油田凝析油的油源及成藏期

根据原油和烃源岩中三芳甾烷及甲基三芳甾烷组成特征,结合稳定碳同位素值,分析了苏北盆地溱潼凹陷红庄油田古近系凝析油的油源特征。结果表明,红庄油田凝析油主要来源于溱潼凹陷深部烃源岩,而并非来自于古近系烃源岩。应用储层岩石流体包裹体测试技术,根据油气包裹体特征及盐水包裹体均一化温度,结合地层埋藏史,分析了红庄油田S245井戴一段砂岩储层流体成藏期次。研究表明,与烃类包裹体共生的盐水包裹体均一化温度分布范围主要介于80～110℃,油气充注时期为新近纪中新世晚期,开始充注的时间大约为6 Ma。     

塔里木盆地柯克亚地区天然气和凝析油的地球化学特征与成区

柯克亚气田的油气成因复杂，对原油和可能烃源岩的分子标志物特征进行了剖析，在凝析油中检测到3-甲基甾烷，不含4-甲基甾烷，富含重排藿烷和C30^-未知萜烷．表明油源主要来自于二叠系源岩。柯克亚的天然气重烃含量高，属湿气，乙烷碳同位素偏重；天然气氩同位素和成熟度特征均指示混源气特征，通过气源判识天然气主要来源于石炭系一二叠系源岩，部分来源于侏罗系源岩。天然气的乙烷δ^13C值明显重于凝析油全油δ^13C值，揭示柯克亚地区凝析油和天然气分属不同来源。     

银额盆地查干凹陷原油地化特征及油源对比

银额盆地东部查干凹陷首次发现轻质低硫成熟原油，其饱和径含量在90％以上，成熟度相当于镜煤反射率Ro1．0％左右，是生油高峰阶段的产物；原油全碳同位素δ^13C值－31．1‰。原油生物标志物中类异戊二烯含量较高，植烷与姥皖烷均势；三环萜烷含量高于五环萜烷；含有较高的TS C29、Ts、C30重排藿烷、伽马蜡烷；藿烷中以C50藿烷为主，C32以上升藿烷含量极低；孕甾烷含量高；甾烷中以C29甾烷为主，C27甾烷含量也较高，异胆甾烷含量高于胆甾烷；重排甾烷含量低；甾烷的含量与萜烷含量相当，是典型的湖相原油。已发现的天然气中甲烷含量达80％，为湿气。原油和源岩生物标志物组成特征分析对比表明下白垩统巴音戈壁组源岩是主要油源岩。生物标志物特征示原油具有一定的运移效应。     

渤海湾盆地南堡油田原油特征与油源分析

南堡油田是渤海湾盆地近年发现的油气储量可观的新油田,为揭示该油田原油特征与成因,对43个原油样品、31块泥岩样品进行详细的地球化学研究与油源对比。依据特征生物标志物、单体烃碳同位素分析,将南堡油田原油分为3种类型:Ⅰ类,南堡1、2号构造带古近系+新近系原油;Ⅱ类,南堡3、4、5号构造带古近系+新近系原油;Ⅲ类,南堡凹陷已发现奥陶系潜山原油。Ⅰ类原油以较低的重排甾烷/规则甾烷,较高的甾烷/藿烷、4-甲基甾烷/C29规则甾烷、伽马蜡烷/C30藿烷值及正构烷烃单体烃碳同位素相对偏重等特征区别于Ⅱ类原油;Ⅲ类原油以较高成熟度、正构烷烃单体烃碳同位素总体偏重等特征不同于Ⅰ、Ⅱ类原油。油源对比结果表明,Ⅰ类原油为沙二+三段、东三段—沙一段烃源岩的混合贡献,Ⅱ类原油主要来源于东三段—沙一段烃源岩,Ⅲ类原油主要来源于沙二+三段烃源岩。首次明确提出南堡1、2号构造带古近系+新近系原油主要为沙二+三段烃源岩的成烃贡献,沙二+三段烃源岩为南堡油田主力烃源岩之一,这对南堡油田油气资源评价和勘探方向决策具有参考意义。     

准噶尔盆地沙湾凹陷原油地球化学特征与油源分析

沙湾凹陷作为准噶尔盆地西北缘重要的油气富集凹陷,在红车断裂带和斜坡区域均有重大油气发现。为明确沙湾凹陷周缘构造原油的来源,采用全烃地球化学分析方法,分析准噶尔盆地西北缘地区4套烃源岩和原油的地球化学特征,进行油-源和油-油对比研究。研究认为沙湾凹陷原油可分为5类,5类原油生物标志化合物指标与碳同位素分别表现为不同的特征,其中:A₁亚类原油来源于二叠系下乌尔禾组烃源岩高成熟阶段,A₂亚类原油来源于下乌尔禾组烃源岩成熟阶段,B类原油来源于风城组和下乌尔禾组的烃源岩的混合,C类原油来源于二叠系风城组烃源岩成熟—高成熟阶段,D类原油为侏罗系烃源岩产物。     

准噶尔盆地永进地区油源研究

在分析和归纳可能烃源岩的有机地化特征并对原油样品进行分析测试的基础上,主要运用生物标志物和稳定碳同位素指标或参数,首次对准噶尔盆地永进地区原油的来源进行了系统研究,认为中二叠统和中下侏罗统烃源岩是为该地区提供油源的主要烃源岩,其次为下二叠统烃源岩,并可能有白垩系烃源岩的贡献。其中,中侏罗统西山窑组煤层之上及大部分白垩系储层中的正常原油主要来自中二叠统烃源岩;煤层之下及下侏罗统三工河组储层中的正常原油主要来自中下侏罗统烃源岩;在现今油藏中所占比例较小并已发生强烈生物降解的原油来自下二叠统烃源岩;永6井白垩系储层中的原油可能来自下白垩统烃源岩,但该套烃源岩的供烃规模可能较小。     

西藏尼玛盆地沥青显示带的发现及油源对比

在西藏尼玛盆地东部赛布错凹陷发现呈东西向展布的沥青显示带,表明该区具有一定的油气勘探前景。为明确该沥青的地球化学特征及具体来源,对尼玛盆地采集的沥青样品进行了饱和烃气相色谱质谱分析,取得以下认识：该沥青处于成熟阶段;高碳数正构烷烃(> nC25)含量高,Σ(≤nC21)/Σ(≥nC22)、(nC21+nC22)/(nC28+nC29)比值较小,藿烷ααα-20RC29优势较明显,说明在有机质的来源上陆源高等植物更占优势。将沥青样品与康嘎勒出露的牛堡组暗色岩系生物标志化合物特征进行对比分析,结果表明二者具有良好的亲缘关系,证实了尼玛盆地为自生自储的陆相含油气盆地。     

内蒙古突泉盆地突参1井原油地球化学特征与油源分析

在内蒙古突泉盆地牤牛海坳陷南部突参1井的1684.5~1698.2m深度段侏罗系万宝组发现轻质原油,揭示了该区较好的油气勘探新领域。对该井原油和主要烃源岩分子地球化学特征、族组分稳定C同位素等进行了分析认为,该原油为轻质高蜡原油,C31升藿烷、C29甾烷异构化等成熟度参数显示该原油为成熟原油。正构烷烃呈单峰前峰型,姥鲛烷较植烷占绝对优势(Pr/Ph2.5),C29规则甾烷含量远高于C27甾烷,伽马蜡烷含量低,表明该原油生烃母质形成于以陆源高等植物为主的偏氧化沉积环境,原油来自该区侏罗系万宝组煤系泥岩。     

Molecular fossils and sources of Cambrian heavy oil of Well Tadong-2 in the Tarim Basin,Xinjiang, China

Research on the molecular fossil characteristics of heavy oil from Well Tadong-2 is of great importance to constrain the source of marine crude oils in the Tarim Basin, Xinjiang, China. The authors synthetically applied the isotope mass spectrograph, chromatography and chromatography-mass spectrography to the studies of molecular fossil characteristics of heavy oil from Well Tadong-2 in the Tarim Basin, and the results obtained revealed that heavy oil from Well Tadong-2 is characterized by high gammacerane, high C₂₈ sterane, low rearranged sterane and high C₂₇-triaromatic steroid, these characteristics are similar to those of Cambrian-Lower Ordovician source rocks, demonstrating that Cambrian crude oils came from Cambrian-Lower Ordovician source rocks; condensed compounds (fluoranthene, pyrene, benzo[a]anthracene, bow, benzo fluoranthene, benzopyrene) of high abundance were detected in heavy oil from Well Tadong-2, and the carbon isotopic values of whole oil are evidently heavy, all the above characteristics revealed that hydrocarbons in the crude oils became densified in response to thermal alteration.     

Geochemical characteristics of crude oils from Well Zheng-1 in the Junggar Basin, Xinjiang, China

Well Zheng-1 is located in the combined area of the central uplift and the north Tianshan piedmont depression in the Junggar Basin. Two oil-bearing beds are recognized at 4788–4797 m of the Lower Cretaceous Tugulu Formation (K1tg) and 4808.5–4812.5 m of the Lower Jurassic Sangonghe Formation (J1s). The geochemical characteristics of family composition, carbon isotopic composition, saturated hydrocarbons, sterane and terpane biomarkers and carotane of two crude oils are described in this paper. The results show that the geochemical characteristics of the two crude oils are basically similar to each other, indicating they were all derived mainly from the high mature, brine, algae-rich lake facies sediments. Oil-source correlation revealed that crude oils of the two beds were derived mainly from the source rocks of Permian and mixed by the oil derived from the source rocks of Jurassic and Triassic. This is consistent with the geological background with several sets of source rocks in the area studied.     

塔里木盆地塔东2井寒武系稠油地球化学特征与成藏

剖析塔东2井稠油的地球化学特征与形成过程,对深化塔里木盆地海相原油的成藏特征具有重要的意义。综合运用碳同位素、色谱、色谱—质谱等技术手段研究了塔东2井寒武系稠油的特征,研究结果揭示塔东2井寒武系稠油具高伽马蜡烷、高C28甾烷、低重排甾烷和高C27 三芳甾烷的特征,与寒武系—下奥陶统烃源岩的分子特征类似,说明塔东2井寒武系原油源自寒武系—下奥陶统烃源岩;塔东2井稠油中检出高丰度的稠环化合物（荧蒽、芘、苯并\[a\]蒽、屈、苯并荧蒽、苯并芘）,及全油的碳同位素值明显偏重,揭示了原油烃类经热蚀变发生稠化;流体包裹体均一化温度和埋藏—热演化史分析确定了塔东2井原油的成藏期为450~440 Ma。     

松辽盆地南部上白垩统烃源岩和原油中正构烷烃的氢同位素组成研究

以松辽盆地南部上白垩统的烃源岩及原油为研究对象,对烃源岩抽提物和原油中正构烷烃的单体氢同位素组成进行了测定。生物标志化合物和正构烷烃的碳氢同位素组成特征表明,在未成熟—成熟阶段正构烷烃的单体氢同位素组成受热成熟度的影响不明显,可以作为油源对比的一个有用的辅助指标。氢同位素组成在母源判识以及重建古沉积环境方面可以提供更多的信息,与碳同位素组成结合应用具有一定的优势。     

北黄海盆地LV井侏罗系烃源岩特征及油源对比

对北黄海盆地LV井中、上侏罗统烃源岩及上侏罗统原油（油砂抽提物）进行常规有机地球化学分析和碳同位素测试,分析研究烃源岩和原油的地球化学特征并探讨原油的来源问题。测试结果显示,侏罗系烃源岩达成熟-高熟阶段,有机质类型以Ⅲ型为主。中侏罗统烃源岩有机碳含量较高,但生烃潜能、氯仿沥青“A”及总烃含量低值,属于差的烃源岩。干酪根碳同位素总体偏重（-24.4‰～-23.5‰）,与原油碳同位素特征（-29‰左右）差异显著,排除与原油的母岩关系。上侏罗统烃源岩有机碳含量较中侏罗统低,但生烃潜能、氯仿沥青“A”及总烃含量高值。上侏罗统烃源岩抽提氯仿沥青“A”碳同位素（-26‰～-21.5‰）特征、单体烃碳同位素分布模式及甾萜烷生物标志物特征都与原油相似,综合分析认为原油应该来源于上侏罗统中干酪根类型较好、母质为混源的成熟烃源岩。     

卡塔克隆起中1井储层沥青地球化学特征与成因

塔里木盆地海相原油的成因至今仍有争议,而对储层沥青的地球化学特征剖析,能为探索海相原油的成因提供依据。选取卡塔克隆起上的中1井不同层系储层沥青,详尽剖析了其地球化学特征。研究结果揭示,中1井储层沥青的Pr/Ph为1.14～1.39,CPI值 1.01～1.08,OEP值0.98～1.05,无奇偶优势或偶奇优势,伽玛蜡烷、C28甾烷丰度低,硫芴系列丰富。甾烷成熟度参数和Ts/(Ts+Tm)均指示中1井储层沥青处于成熟—高成熟热演化范畴。依据特征生物标志物的分布对沥青的成因示踪,中1井储层沥青与上奥陶统烃源岩有成因关系,而中1井储层沥青与塔东2井寒武系原油分子特征的迥异也佐证该认识。     

哈得逊与轮南地区原油碳同位素特征及影响因素

轮南地区与哈得逊地区20个原油的全油碳同位素和正构烷烃单体烃碳同位素的分析结果表明:轮南地区原油的全油碳同位素均大于-32‰,而哈得逊地区原油的全油碳同位素一般小于-32‰;原油正构烷烃单体烃碳同位素也表现出轮南地区重于哈得逊地区的特征。两地区原油碳同位素的这种特征是由于两地区油气成藏过程的差异造成的,轮南地区原油碳同位素比哈得逊地区的原油碳同位素重的主要原因是由于来源于寒武系降解原油的混入,而非油源不同造成的。     

Origin of Shallow Jurassic Heavy Oils in the Northwestern Margin of the Junggar Basin, NW China: Constraints from Molecular, Isotopic and Elemental Geochemistry

Oil group separation, gas chromatography–mass spectrometry analysis of saturated hydrocarbons, carbon isotope analysis of fractions and tests on trace elements were all carried out to determine the origin of shallow Jurassic heavy oils in the northwestern margin of the Junggar Basin, northwestern China. Results showed that all the crude oils had been subjected to different degrees of biodegradation, on an order ranging from PM 6 to 9, which yielded many unresolved complex mixtures (UCM) and formed a huge spike in the mass chromatogram (M/Z = 85). Two heavy oils from the Karamay area underwent slight biodegradation, characterized by the consistent ratios of biomarker parameters. C21/C23 and C23/H of the two samples were 0.81 and 0.85, while G/H, C27/C29 and C28/C29 were 0.38 and 0.40, 0.16 and 0.27, 0.87 and 0.86, respectively. The isomerization parameters of terpane and steranes were 0.50–0.53, and 0.48–0.49, respectively. The above geochemical indices indicated that the crude oils in the study area were in the marginally mature stage. The parent materials were a mixture, consisting of bacteria, algae and some higher plants, formed under reducing depositional conditions, which is in agreement with the source rocks of the Fengcheng Formation in the Mahu depression. The carbon isotopic compositions of saturated hydrocarbon, aromatic hydrocarbon, NSO and asphaltene were ?31‰? to ?30.3‰, ?29.5‰ to ?29.03‰, ?29.4‰ to ?28.78‰ and ?28.62‰ to ?28.61‰, respectively. These findings are in agreement with the light carbon isotope of kerogen from the lower Permian Fengcheng Formation. Furthermore, V/Ni and Cr/Mo of all the crude oils were 0.01 to 0.032, 0.837 to 10.649, which is in good agreement with the ratios of the corresponding elements of the extracts from the Fengcheng Fm. carbonate source rock. As a result, a two–stage formation model was established: (1) the oil generated from the carbonate source rocks of the Fengcheng Formation migrated to the Carboniferous, Permian and Triassic traps during the Late Triassic, forming the primary oil reservoirs; (2) during the Late Jurassic period, the intense tectonic activity of Yanshan Episode II resulted in the readjustment of early deep primary reservoirs, the escaped oils gradually migrating to the shallow Jurassic reservoir through cross-cutting faults, unconformities and sand body layers. The oils then finally formed secondary heavy oil reservoirs, due to long–term biodegradation in the later stage. Therefore, joint methods of organic, isotopic and element geochemistry should be extensively applied in order to confirm the source of biodegradation oils.