阿姆河盆地侏罗系海相烃源岩地化特征及与中国海相烃源岩比较

阿姆河盆地上侏罗统海相烃源岩是一套公认的成熟烃源岩,其成熟度与中国古生界高-过成熟度海相烃源岩不同,通过对阿姆河右岸地区上侏罗统岩石样品的地球化学分析及与中国塔里木和华北、四川、吐哈、渤海湾等盆地类似烃源岩的比对,研究了阿姆河盆地成熟海相烃源岩地化特征,建立了有机质丰度与类型的评价标准与图版。结果表明:阿姆河盆地侏罗系存在灰岩和泥岩两类海相烃源岩,灰岩有机质丰度略高于塔里木盆地古生界和华北地台中上元古界灰岩,与四川盆地二叠系灰岩接近,泥岩有机质丰度与吐哈盆地侏罗系煤系泥岩相当,成倍好于塔里木盆地、华北地台海相泥岩;海相泥岩属于Ⅰ₂~Ⅱ型烃源岩,海相灰岩属于Ⅲ~Ⅱ型烃源岩,综合分析认为:1）阿姆河盆地上侏罗统灰岩好烃源岩有机碳含量标准为0.5%,泥岩好烃源岩有机碳含量标准为3%;2）以低等生物为主的海相碳酸盐岩或泥岩,其可溶有机质氯仿沥青“A”族组分、Pr/Ph与Ph/nC₁₈关系、甾烷ααα（C₂₇、C₂₈、C₂₉）-20R含量、多环芳香“三芴”系列等参数既揭示了烃源岩的生源环境,也是鉴别母质类型的良好参数。阿姆河盆地上侏罗统海相泥岩和灰岩烃源岩评价标准与图版的建立,对国外海相盆地油气资源评价具有重要意义。     

北羌塘盆地布曲组烃源岩生物标志物特征及意义

北羌塘盆地发育的布曲组海相碳酸盐岩是重要的烃源岩之一,但是由于研究程度低,一些油气地球化学问题尚不清楚。应用生物标志物分析技术,结合其它地球化学资料,对北羌塘盆地侏罗系布曲组烃源岩进行了有机质生源构成、沉积环境、成熟度进行了讨论。研究结果表明,该烃源岩的发育环境为海相还原环境,有机质母质主要为低等水生生物,有高等植物的混入,处于高成熟阶段,具备油气生成的有力条件。     

青藏高原羌塘盆地油气生成特征

本文从沉积、地球化学的角度分析了羌塘盆地的油气生成特征.羌塘盆地的沉积及古地理环境控制了多层系生油岩的形成,但主要为三叠系和侏罗系以海相沉积为主的碳酸盐烃源岩和泥质烃源岩,厚度巨大,有机质丰度高,热演化程度较高,生烃潜力大,构成了羌塘盆地主力烃源岩.综合分析认为盆地南北坳陷连接处的鞍部为含油气远景最有利区.     

Study of the Factors Affecting the Abundance of Organic Matter in Jurassic Carbonate Rocks in Qiangtang Basin, Tibet

Field and laboratory analyses of carbonate rock samples from the Qiangtang Basin,Tibet, indicate that carbonate source rocks are mainly developed in the Middle Jurassic Xiali Formation and Upper Jurassic Suowa Formation. Comprehensive studies showed that the Suowa Formation carbonate source rocks have a favorable hydrocarbon-generating potential. The abundance of organic matter in the carbonate rocks is controlled mainly by sedimentary environment and inorganic compounds in the rocks, which is higher in the restricted platform facies than in the open platform facies. Organic carbon contents decrease with increasing CaO contents in the source rocks.     

南祁连盆地热水—默勒地区上三叠统可能烃源岩地球化学特征

应用多项分析测试技术，对南祁连盆地热水－默勒地区上三叠统可能烃源岩进行了有机质丰度，类型、成熟度、有机母源和沉积环境等方面的分析。该区上三叠统可能烃源岩为前三角洲和湖沼相的泥质岩沉积，其有机质丰度较高，有机质类型为腐殖型和混合型，主要处于成熟阶段，有机母质主要为高等植物和一定数量的藻菌类低等水生生物的贡献。综合分析认为该套地层具有一定的生烃能力，其中一些层段生烃潜力较大。     

CONTRAST STUDY OF OIL AND GAS EXPLORATION POTENTIAL FOR QIANGTANG, CHANGDOU AND WEST YUNNAN BASIN DURING JURASSIC

CONTRAST STUDY OF OIL AND GAS EXPLORATION POTENTIAL FOR QIANGTANG, CHANGDOU AND WEST YUNNAN BASIN DURING JURASSIC     

Petroleum Geological Conditions in Qiangtang Basin

PETROLEUM GEOLOGICAL CONDITIONS IN QIANGTANG BASIN     

莺琼盆地中新统海相烃源岩地球化学特征及生烃潜力评价

通过有机碳测定、岩石热解分析、显微组分定量分析、饱和烃色谱、色谱-质谱等实验分析,对莺琼盆地中新统海相烃源岩的地球化学特征进行了研究,探讨了不同层位烃源岩的生烃潜力。结果表明：莺琼盆地中新统海相烃源岩有机质丰度总体较低,大部分烃源岩为中等烃源岩,有机质类型以Ⅱ2型和Ⅲ型为主,有机质热演化主要处于成熟阶段。烃源岩显微组分组成具有富含镜质组、壳质组+腐泥组次之、贫含惰性组的特征。烃源岩沉积环境主要为弱氧化-弱还原环境,具有陆生高等植物和低等水生生物生源混合输入的特征。莺歌海盆地梅山组烃源岩综合评价为中等烃源岩,生烃潜力相对较好,三亚组烃源岩综合评价为较差—中等烃源岩,具有一定的生烃潜力。琼东南盆地梅山组和三亚组烃源岩综合评价为中等烃源岩,具有相当的生烃潜力。     

柴达木盆地北缘侏罗系页岩气资源潜力分析

柴达木盆地北缘侏罗系是中国西北地区重要的含煤岩系,同时也是重要的烃源岩层段。在柴北缘侏罗系有多个厚层泥页岩分布区,整体来看西北部泥页岩厚度大于东南部,其中鄂博梁—冷湖地区在中侏罗世长期处于沉积中心,沉积环境主要为浅湖和半深湖,水体稳定,碎屑物质供给充足,沉积了一套厚—巨厚层泥页岩,有效泥页岩厚度在600~1200m。根据干酪根元素组成等测试结果,研究区侏罗系泥页岩中的有机质类型为Ⅱ—Ⅲ2型,以生气为主生油为辅。泥页岩有机碳平均含量为2.02%,其中冷湖地区泥页岩有机质含量最高,可达8.26%。中、下侏罗统烃源岩除鱼卡、大煤沟成熟度较小外,其它地区均进入生气高峰期,个别地区已达过成熟阶段。柴北缘侏罗系泥页岩厚度大、有机质含量较高,成熟度适中,初步认为具备形成页岩气藏的良好地质条件。     

西藏南羌塘盆地侏罗系烃源岩地球化学特征

依据剖面露头样品的实验测试资料,通过Rock-Eval岩石评价、显微镜下观察、镜质体反射率、烃源岩可溶有机质特征、单体烃碳同位素等分析方法,对南羌塘盆地侏罗系烃源岩地球化学特征进行综合研究。研究结果表明:南羌塘盆地侏罗系烃源岩有机质丰度较低,总体上夏里组泥质烃源岩要好于布曲组和索瓦组碳酸盐岩烃源岩;烃源岩的有机质类型较好,主要为Ⅱ1型,并且反映出烃源岩形成于具一定盐度的较强还原环境,其有机质以海相低等水生生物为主;烃源岩的热演化程度总体较高,达到高成熟阶段。正构烷烃单体烃碳同位素分析表明,侏罗系各组烃源岩之间在母质输入上可能存在较大差异,该地区白云岩油苗与夏里组泥质烃源岩有很强亲缘关系。     

羌塘盆地胜利河地区布曲组油气地球化学特征与油源对比

羌塘盆地胜利河地区侏罗系海相地层的地表露头有大量的油气显示。以往研究表明该地区发育多套含油气系统,油气性质复杂。本次研究在前人工作基础上,以中侏罗统布曲组(J₂b)中部油页岩露头、探井岩心的油气显示以及地表油气显示为主要研究对象。通过TOC分析、岩石热解、饱和烃色谱和饱和烃色谱-质谱的分析,更为详细地研究了胜利河地区烃源岩类型,对原油来源进行了进一步探讨,为该地区下一步油气勘探工作提供更多的理论依据。研究表明,该地区J₂b组中部油页岩有机质类型以Ⅱ型为主,具有较高的生油潜力。该地区原油主要来源于还原性海相沉积环境。研究区样品的有机质输入主要以低等水生生物为主, DB4142以低等水生生物和高等植物混合贡献,BD4902以高等植物输入为主。原油处于成熟阶段,所有样品均检测出25-降藿烷系列的化合物,指示样品均遭受了较为强烈的生物降解作用。依据生物标志物指纹特征和生物标志化合物参数特征,运用聚类分析方法,将研究区原油划分为A、B、C、D四类。其中A类原油主要来自于同层位(J₂b)的烃源岩,而B、C、D类原油没有或者很少有该套...     

柴达木盆地北缘中侏罗统大煤沟组七段烃源岩有机地球化学特征及生烃潜力

柴达木盆地北缘地区在中侏罗世晚期,即大煤沟组七段(J2d7)时演化至最大湖侵期,发育了一套湖相泥页岩。通过对区内鱼卡煤矿井下样品的实测分析,结合先前报道的研究成果,确认了这套湖相泥页岩为优质烃源岩,藻类体、角质体和孢子体是这套源岩的主要生烃显微组分,有机质类型最好可达II1型。热演化研究表明,该套源岩在不同构造单元处于差异热演化阶段,既可生油亦可生气。虽然J2d7段烃源岩在平面上不同凹陷区具有一定的非均质性,但其生烃潜力,特别是在赛什腾—鱼卡凹陷地区,完全可与我国西北地区其它侏罗系优质烃源岩相媲美。长期以来,下侏罗统烃源岩被认为是柴北缘地区的主要油气源,J2d7段优质烃源岩的确认,对于深化柴北缘地区的油气勘探和地质研究具有重要意义。     

大杨树盆地中部甘河地区嫩江组烃源岩生烃潜力分析

通过岩石热解、总有机碳、镜质体反射率、饱和烃气相色谱-质谱等测试方法,系统分析大杨树盆地中部甘河地区嫩江组烃源岩有机地球化学、生物标志化合物特征,评价其生烃潜力。结果表明,大杨树盆地中部甘河地区嫩江组暗色泥岩有机质丰度较高,属于中等-好烃源岩,有机质类型主要为Ⅱ型干酪根,处于成熟阶段,是一套好的烃源岩。烃源岩形成于还原性的淡-微咸水的水体沉积环境中,有机质来源为混合来源,且以陆生高等植物来源贡献较大。总体显示大杨树盆地中部甘河地区嫩江组烃源岩具有一定的生烃潜力。     

羌塘盆地上三叠统土门格拉组烃源岩生物标志物地球化学特征

首次对羌塘盆地上三叠统土门格拉组烃源岩生物标志化合物特征进行了研究,揭示了生物标志化合物对该地区有机质生源构成、沉积环境和成熟度的指示意义。研究结果表明：土门格拉组烃源岩中的有机母质为混合来源,既有陆生植物来源,又有低等水生生物来源,烃源岩的沉积环境为具有一定盐度的还原环境。烃源岩成熟度参数显示,土门格拉组烃源岩有机质演化程度已达到高成熟阶段。生物标志化合物的这些特征进一步证实了土门格拉组烃源岩具有较好的生烃潜力。     

云南禄劝地区泥盆系油苗地球化学特征及地质意义

随着四川盆地海相常规天然气和页岩气勘探开发的成功,新区、新层系的油气勘探逐渐提上议程。云南地区泥盆系泥页岩在局部地区广泛分布,有机质丰度较高,但钻井工作很少,研究较为薄弱,油气富集情况不明。通过野外调查,在云南禄劝地区中泥盆统华宁组发现了液态油苗。有机地球化学分析表明:油苗与中泥盆统华宁组三段的泥灰岩亲缘关系较好;中泥盆统华宁组三段的泥灰岩整体沉积于强还原—还原环境,生烃母质主要为藻类等低等水生生物,也有来自高等植物的贡献,已处于成熟阶段,具有较强的油气生成能力,生烃能力与Ⅱ₁型烃源岩相当;康滇古陆西缘泥盆系泥灰岩有过生油气过程,生成的原油以饱和烃和芳香烃为主,且保存条件好的情况下,具有一定的页岩油气和常规油气勘探前景。      

内蒙古海拉尔盆地侏罗系烃源岩地球化学特征

在海拉尔盆地外围及周边地区选取了31块侏罗系野外烃源岩分析样品,进行了总有机碳、岩石中可溶有机质的抽提和岩石热解分析;针对该区侏罗系烃源岩,共对17口井岩心进行了取样地化分析,利用气相色谱-质谱对烃源岩氯仿抽提物及重要生物标志化合物开展了定性与定量检测,目的是对源岩地球化学特征进行系统评价,为下一步油气基础地质调查奠定基础.结果表明,海拉尔盆地外围及周边地区的侏罗系部分的烃源岩有机质丰度较高,应具备较好的生烃物质基础.海拉尔盆地侏罗系烃源岩总体属于淡水-半咸水环境,有机质类型多样,成熟度普遍较高.甾类化合物中以规则甾烷为主,沉积物中具有较高丰度的以五环三萜烷为主的三环萜烷化合物,显示了其应以藻类生源为主,高等植物为主的陆相沉积中的相对含量则较低.伽马蜡烷的含量普遍很低.OEP呈偶碳数优势,并且缺失高分子正构烷烃,说明烃源岩成熟度演化早期受到了微生物降解作用.     

Characteristics and evaluation of Mesozoic source rocks in the southeastern East China Sea continental shelf

Source rocks are the material basis of oil and gas generation and determine the potential resources of exploration blocks and have important research value. This paper studies the lithology, thickness, and geochemistry of Mesozoic source rocks in the southeastern East China Sea continental shelf. The results show that the Mesozoic source rocks are mainly dark mudstone and coal-bearing strata. The total thickness of Lower–Middle Jurassic source rocks ranges from 100 m to 700 m, and that of Lower Cretaceous source rocks ranges from 50 m to 350 m. The overall thickness of Mesozoic source rocks is distributed in the NE direction and their thickness center is located in the Jilong Depression. The Lower–Middle Jurassic source rocks are mainly developed shallow marine dark mudstone and transitional coal measure strata. Those of the Lower Cretaceous are mainly mudstone of a fan delta front. Lower–Middle Jurassic and Lower Cretaceous hydrocarbon source rocks are dominated by type III kerogen, with Lower–Middle Jurassic hydrocarbon source rocks having high organic matter abundance and being medium–good hydrocarbon source rocks, while Lower Cretaceous hydrocarbon source rocks have relatively poor quality. From northwest to southeast, the vitrinite reflectance Ro of Mesozoic source rocks increases gradually. Source rocks in the study area are divided into three types. The first hydrocarbon-generating area is mainly located in the southeastern region of the study area, and the Jilong Depression is the hydrocarbon-generating center. The results of this study can provide a basis for exploration of Mesozoic oil and gas resources in the southeastern East China Sea continental shelf.© 2019 China Geology Editorial Office.     

Molecular composition and organic petrographic characterization of Madbi source rocks from the Kharir Oilfield of the Masila Basin (Yemen): palaeoenvironmental and maturity interpretation

The upper part of Madbi Formation organic-rich shale is considered an important regional source rock in the Masila Basin, Yemen. Ten cutting samples from this Upper Jurassic organic-rich shale were collected from wells drilled in the Kharir Oilfield, Masila Basin in order to geochemically assess the type of organic matter, thermal maturity and depositional environment conditions. Results reveal that Upper Jurassic organic-rich shale samples contain high organic matter more than 2.0 wt.% TOC and have very good to excellent hydrocarbon potential. Marine algae organic matter is the main source input for the Upper Jurassic shale sequence studied. This has been identified from organic petrographic characteristics and from the n-alkane distributions, which dominated by n-C₁₄-n-C₂₀ alkanes. This is supported by the high value of the biomarker sterane/hopane ratio that approaches unity, as well as the relatively high C₂₇ sterane concentrations. A mainly suboxic depositional environment is inferred from pr/ph ratios (1.75–2.38). This is further supported by relatively high homohopane value, which is dominated by low carbon numbers and decrease towards the C₃₅ homohopane. The concentrations of C₃₅ homohopane are very low. The depositional environment conditions are confirmed by some petrographic characteristics (e.g. palynofacies). Detailed palynofacies analysis of Madbi shales shows that the Madbi shale formation is characterised by a mix of amorphous organic matter, dinoflagellates cysts and phytoclasts, representing a suboxic, open marine setting. The Upper Jurassic marine shale sequence in the Masila Basin is thermally mature for hydrocarbon generation as indicated by biomarker thermal maturity parameters. The 22 S/22 S + 22R C₃₂ homohopane has reached equilibrium, with values range from 0.58 to 0.62 which suggest that the Upper Jurassic shales are thermally mature and that the oil window has been reached. 20 S/(20 S + 20R) and ββ/(ββ + αα) C₂₉ sterane ratios suggest a similar interpretation, as do the moretane/hopane ratio. This is supported by vitrinite reflectance data ranging from 0.74% to 0.90%Ro and thermal alteration of pollen and spore. The thermal alteration index value is around 2.6–3.0, corresponding to a palaeotemperature range of 60–120°C. These are the optimum oil-generating strata. On the basis of this study, the Madbi source rock was deposited under suboxic conditions in an open marine environment and this source rock is still within the oil window maturity range.     

西藏羌塘盆地中生界烃源岩探讨

羌塘盆地位于青藏高原中北部全球油气产量最高、储量最丰的特提斯构造域中段，是一复合对称型前陆盆地，具有广泛的中生界海相沉积和中国最年轻的海相地层，沉积厚度可达万米，其中侏罗系占一半以上。盆地经历了晚古生代大陆边缘沉积阶段、三叠纪陆间裂谷阶段、侏罗纪大陆边缘沉积阶段和侏罗纪末班公湖—怒江缝合带闭合以来的构造反转挤压一长期剥蚀阶段。羌塘盆地中生代具有广泛分布且发育良好的烃源岩，烃源岩厚度大，最厚处可达3000m以上，其中上三叠统的肖茶卡组、中侏罗统布曲组和夏里组有机质类型好，丰度高，成熟度从成熟到过成熟均有分布。埋藏较好，其生油量巨大，是盆地油气的主要来源之一。     

Hydrocarbon potential of the Sargelu Formation,North Iraq

Microscopic and chemical analysis of 85 rock samples from exploratory wells and outcrops in northern Iraq indicate that limestone, black shale and marl within the Middle Jurassic Sargelu Formation contain abundant oil-prone organic matter. For example, one 7-m (23-ft.)-thick section averages 442 mg?HC/g S2 and 439 °C Tmax (Rock-Eval pyrolysis analyses) and 16 wt.% TOC. The organic matter, comprised principally of brazinophyte algae, dinoflagellate cysts, spores, pollen, foraminiferal test linings and phytoclasts, was deposited in a distal, suboxic to anoxic basin and can be correlated with kerogens classified as type A and type B or, alternatively, as type II. The level of thermal maturity is within the oil window with TAI?=?3^? to 3⁺, based on microspore colour of light yellowish brown to brown. Accordingly, good hydrocarbon generation potential is predicted for this formation. Terpane and sterane biomarker distributions, as well as stable isotope values, were determined for oils and potential source rock extracts to determine valid oil-to-source rock correlations. Two subfamily carbonate oil types—one of Middle Jurassic age (Sargelu) carbonate rock and the other of Upper Jurassic/Cretaceous age—as well as a different oil family related to Triassic marls, were identified based on multivariate statistical analysis (HCA and PCA). Middle Jurassic subfamily A oils from Demir Dagh oil field correlate well with rich, marginally mature, Sargelu source rocks in well MK-2 near the city of Baiji. In contrast, subfamily B oils have a greater proportion of R₂₈ steranes, indicating they were generated from Upper Jurassic/Lower Cretaceous carbonates such as those at Gillabat oil field north of Mansuriyah Lake. Oils from Gillabat field thus indicate a lower degree of correlation with the Sargelu source rocks than do oils from Demir Dagh field. One-dimension petroleum system models of key wells were developed using IES PetroMod Software to evaluate burial-thermal history, source-rock maturity and the timing and extent of petroleum generation; interpreted well logs served as input to the models. The oil-generation potential of sulphur-rich Sargelu source rocks was simulated using closed system type II-S kerogen kinetics. Model results indicate that throughout northern Iraq, generation and expulsion of oil from the Sargelu began and ended in the late Miocene. At present, Jurassic source rocks might have generated and expelled between 70 % and 100 % of their total oil.