柴达木盆地北缘侏罗系烃源岩干酪根13C核磁共振研究

柴达木盆地北缘是柴达木盆地三大油气区之一,其源岩为早、中侏罗世煤系地层.烃源岩有机质类型以Ⅲ₁型和Ⅱ型干酪根为主,Ⅰ₂型干酪根仅在局部地区有分布.通过对柴达木盆地北缘侏罗系烃源岩中不同类型干酪根的¹³C核磁共振研究,指出了研究区Ⅰ₂、Ⅱ、Ⅲ₁型干酪根的化学结构特征以及化学结构中“芳构碳”、“油潜力碳”与“气潜力碳”的相对含量,据此从定量分析的角度对不同类型干酪根的生油气贡献作了评价.Ⅰ₂、Ⅱ、Ⅲ₁型干酪根的生烃能力依次减弱,对生油的贡献也依次减弱,且生成油气的比例不同,Ⅰ₂、Ⅱ型干酪根以生油为主,Ⅲ₁型干酪根则以生气为主.     

塔里木,准噶尔盆地石油生成与演化

以塔里木、准噶尔盆地干酪根、沥青的Ｐｂ、Ｓｒ、Ｎｄ同位素分析资料，回答了地质学家必须回答的四个问题：①石油是由舒什么生成的；②石油是如何生成的；③石油是地何时生成的；④石油是何时运移的。根据Ｐｂ、Ｓｒ、Ｎｄ同位素所揭示的信息指出，塔里木、准噶尔盆地的石油虽然是在不同构造背景下生成的，生油模式、生油年龄和运移年龄也不相同，但都是由费托合成反应无机生成的。作者指出，地救化学急变对油气田分布的控制作用十     

Economic geology value of oil shale deposits: Ethiopia (Tigray) and Jordan

Oil shale is an organic-rich, fine-grained sedimentary rock, containing kerogen, from which liquid hydrocarbons (called shale oil) can be produced. The oil shale deposits in the Tigray region are found in the northern parts of Ethiopia, Eastern Africa. They are of Upper Paleozoic in age, existing as remnants of the Cretaceous erosion period, underlain by tillites and overlain by sandstones. They were formed during the glacial retreat followed by marine deposition of shales in a basin created by the enormous load of the glaciers. The Ethiopian-Tigray oil shale deposits cover an area extending over approximately 30 km², with an average mineable bed-thickness of 55 m, showing on the upper part inter-beds and laminations of shaley limestones. The oil shale resources in this region are estimated to be approximately 4 billion tonnes. The exploitation of the Ethiopian-Tigray oil shale deposits is an excellent alternative to fulfill the fuel and other petroleum products’ demand of Ethiopia. This study sheds light on the oil shale resources in the Ethiopian region of Tigray, as they are fairly investigated, regarding their geological characterization, and future strategies for their exploration and exploitation potential. In addition, the oil shale deposits in Jordan are also moderately investigated, as Jordan is considered a promising country for shale oil, taking into account that Jordan has no other hydrocarbon resources (such as crude oil and natural gas), unlike many other countries in the MENA (Middle East and North Africa) region, as MENA sets on “seas” of oil and natural gas. Furthermore, oil shale in the USA is also briefly investigated, as the USA is being the world’s largest country of oil shale resources and reserves. Also, some other issues related to the oil shale industry are investigated, such as economics, extraction technologies of shale oil, and the environmental impacts.     

两种裂解气中轻烃组成差异性及其应用

为了寻找干酪根和原油裂解气识别指标，对两种裂解气中轻烃各化合物开展了深入的对比研究。热模拟实验表明干酪根裂解气和原油裂解气轻烃组成存在差异，在C₇轻烃组成中，原油裂解气中甲基环己烷/正庚烷和(2-甲基己烷+3-甲基己烷)/正己烷均明显高于干酪根裂解气；通过对海相典型原油裂解气和干酪根裂解气的轻烃组成对比研究进一步证实了两种裂解气在轻烃组成上存在差异，原油裂解气中甲基环己烷/正庚烷一般大于1.0，(2-甲基己烷+3-甲基己烷)/正己烷一般大于0.5,而干酪根裂解气则反之。塔里木盆地满东－英吉苏地区天然气轻烃组成具有环烷烃和异构烷烃含量高的分布特征，应用上述指标对该区天然气成气过程进行判识，结果表明满东－英吉苏地区天然气主要为原油裂解气。     

Vanadium of petroleum asphaltenes and source kerogens (La Luna Formation, Venezuela): isotopic study and origin

High-resolution mass spectrometry indicates that the isotopic abundance of ⁵⁰vanadium (V) of the Late Cretaceous La Luna petroleum asphaltenes and related source kerogens of marine origin (both highly enriched with V>2000 ppm) is higher by about 3.5% than that of inorganic source (VOSO₄·5H₂O, Merck). Similar results are obtained with the isotopic analysis of the asphaltenes (containing high V) extracted from the floating asphalts (Dead Sea, Israel). We propose that the difference in the ⁵⁰V/⁵¹V values between the La Luna petroleum asphaltenes/source kerogens and inorganic source can be best ascribed to the biological processing of the seawater V. The fact that the isotopic composition of V of the vary over a very narrow range (2.46-2.52) suggests an essentially same (or similar) and fixed (micro)biological source of V. Isotopic analysis was also extended to the methanol-soluble fractions of the La Luna asphaltic petroleums (DM-119/-120/-124) highly enriched with extractable (alkyl) vanadyl-porphyrins (VO²⁺-P). This analysis shows that the isotopic abundance of ⁵⁰V for the methanol-soluble fractions agrees (within the limits of experimental error) with those of the asphaltenes/kerogens.     

Hydrocarbon source-rock potential of the Jurassic succession in eastern part of the North Western Desert,Egypt

The hydrocarbon potential is determined by the quantity and quality of organic matter encountered in the Jurassic sediments in two wells at the Northern Western Desert. It utilizes to define the zones of oil and gas using the well logging data for calculates the total organic carbon (TOC). The evaluation of source rock has been based on two steps; the first one depended on the geochemical parameters including TOC, S1, S2, Tmax, and Vitrinite reflectance (Ro %) of two wells JG-1 and JD-4. The second step was to calculate (TOC) from wireline logs. The well log types utilized in such kind of analysis are the density log, sonic log, resistivity log and gamma-ray log. The stratigraphic sequence, in the studied wells ranges in age from Paleozoic to Recent. The present work focuses on the Jurassic rocks represented by Khatatba Formation as they include the main source horizon. Based on the obtained results, Jurassic sediments called as fair to excellent source rock potential. The genetic type of organic matter can be identified through the study of pyrolysis data, which indicate that is rich in mixed oil and gas-prone kerogen except few samples reflect type I organic facies.     

页岩气藏纳米孔隙气体渗流特征分析

页岩气藏储层孔隙非常细小,国内外页岩孔隙半径主要集中在几个纳米到20个纳米之间,国内部分页岩孔隙半径小于10个纳米。页岩气藏生产受到纳米孔隙中的游离气和吸附于干酪根中吸附气两大主体气源影响,这2种气源气在生产中表现出4种机理。研究了纳米孔隙中气体分子克努森扩散、气体滑脱、达西渗流及吸附于干酪根中气体扩散4种机理下页岩气体渗透率及孔隙压力的变化情况,并以此建立圆柱管内平面单向稳定渗流数学模型。模型模拟结果表明页岩的表观渗透率远远大于达西渗透率,孔隙半径越小,则两者比值越大,当孔隙半径从20个纳米减小到几个纳米,两者比值将会从十增大到几十;孔隙压力越小,则两者比值越大,而当压力小于5MPa时,表观渗透率与达西渗透率之比明显增加1~2个数量级。随着压力降低,克努森扩散作用不断增强,相应的压力损耗不断增加,使得纳米管柱内平面单向从供给边缘到排液道的稳定渗流压力分布已不再是线性分布。干酪根中气体由于扩散速度慢、扩散量小而对压力影响不明显。
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Conversion of oil shale to liquid hydrocarbons

Oil shale is a complex fossil material that is composed of organic matter and mineral matrix. The thermal decomposition of the organic matter generates liquid and gaseous products. Oil shale is a porous rock containing kerogen, an organic bituminous material. Kerogen is a solid mixture of organic compounds that is found in certain sedimentary rocks. The kerogen can be pyrolyzed and distilled into petroleum-like oil. Oil shale and bituminous materials are suitable for obtaining petroleum-like products. The process designed in this study has the ability to control unwanted volatile materials. The mineral matter is removed from oil shale before pyrolysis. The pyrolysis of the oil shale is performed in a retort. The temperature at which the kerogen decomposes into usable hydrocarbons begins at 300°C, but the decomposition proceeds more rapidly and completely at higher temperatures. Decomposition takes place most quickly at a temperature between 475 and 525°C. Shale oil from oil shale consists of the hydrocarbons: paraffins, olefins, isoparaffins and naphthenes, isoolefins and cycloolefins, monocyclic aromatics, and poly-cyclic aromatics. The nonhydrocarbons are nitrogen, sulfur, and oxygen (NSO) compounds.     

茫崖坳陷下第三系有机酸形成演化及空间分布

有机酸的形成及分布越来越受到人们的重视。烃源岩的有机质在向干酪根及油气的转化过程中不断地释放出酸性成分 ,释放的有机酸进入储集层水体将改变水介质性质 ,使地层水由碱性变为酸性 ,有利于次生孔隙的形成。通过恢复地层中的有机酸形成过程 ,正确确定烃源岩排酸量及介质中有机酸的浓度 ,有助于预测研究区储集层次生孔隙的形成、发育和分布状况。文中应用柴达木盆地西部地区的实测数据 ,建立了研究区内Ⅱ型干酪根的有机酸生成及演化模式。以模式为指导 ,结合地层压实理论定量恢复E23 和N1 两套烃源岩的有机酸形成演化过程及空间展布特征 ,指出潜在的储集层次生孔隙发育带分布于油泉子构造、咸水泉构造、南翼山构造和南乌斯构造等。图 2表 1参 4(徐怀民摘 )     

深层多途径复合生气模式及潜在成藏贡献

深层—超深层是当前和未来油气勘探的重要方向,明确高演化阶段天然气的生气途径、机制和潜力,将有助于发展天然气成因理论和指导深层油气勘探。结合大量模拟实验和动力学计算,探讨了不同母质和途径生气的成熟度和温度界限（生气时限）及贡献,建立了深层多途径复合生气模式。提出I/II型有机质或干酪根直接热降解（初次裂解）生气下限可延至R_O=3.5%,最大生气量可达120~140 m³/t_TOC,R_O>2.0%阶段的生气量可达20~40 m³/t_TOC。系统认识了原油全组分裂解动力学过程,提出在2 ℃/Ma地质升温速率条件下,液态烃大规模裂解的地质温度为190~220 ℃,对应的成熟度为R_O=2.0%~2.3%;源内残留烃和源外液态烃裂解生气贡献分别为约80 m³/t_TOC和200 m³/t_TOC,乙烷裂解温度要高于230 ℃。硫酸盐热化学还原作用（TSR）导致液态烃裂解温度降低20~40 ℃,加速高含硫化氢（H₂S）天然气藏的高效聚集;无机流体和矿物参与的加氢生气作用可提高天然气生成潜力20%~30%,是深层高—过成熟天然气生成的途径之一。多途径生气过程构成了天然气形成的完整演化序列,揭示在传统油气“死亡线”之下,深层—超深层仍具有天然气勘探潜力。