A Review of: “Electrochemical Hydrogen Technologies”Edited by Hartmut Wendt Elsevier Science Publishers,B.v,Amsterdam, The Netherlands 1990, xx + 512 pp.

Abstract:

The organic geochemical and biomarker analyses of the Miocene source rocks of some wells in the onshore Nile Delta, suggested that the Abu Madi Formation has poor immature to marginally mature source rocks of Type III Kerogen deposited under the terrestrial environment. The Sidi Salem Formation has fair-to-good mature source rocks of producing mixed oil and gas, originating mainly from marine organic sources. The Moghra Formation has mature good source rocks for Type (II/III) kerogen, derived from organic matter and rich in both terrigeneous and marine sources. The geochemistry of condensates revealed that the Abu Madi and Moghra condensates originated from marine organic matters with little input from a terrestrial source, while Sidi Salem condensate was derived from more contribution of terrestrial organic matters. Abu Madi condensate is less mature than Sidi Salem and Moghra condensate. The geochemical thermal modeling of the Miocene source rocks indicates that the Abu Madi formations are in the early stages of hydrocarbon up until the present time, while Moghra and Sidi Salem formations are in the mature stage of hydrocarbon generation up until the present time. This indicates that the studied condensates have probably migrated from deeply buried source rocks which are at a higher level of maturity rather than from less mature source rocks in the study area.     

柴达木盆地西部咸化湖相优质烃源岩地球化学特征及成藏意义

传统上认为柴达木盆地西部地区咸化湖相烃源岩有机质丰度低,油气主要来源于"可溶有机质"。在柴达木盆地西部首次发现一定规模有机质丰度较高的优质咸化湖相烃源岩,其TOC值一般约在1%,最高可达4%以上;生烃潜量一般大于6 mg/g,最高可达40 mg/g;氢指数一般在500 mg/g(TOC)以上,最高可达900 mg/g(TOC)以上。有机质类型以I型和II1型为主,少量II2型,为倾油型有机质。而有机质丰度过低的样品(TOC0.5%),其类型也较差,所含的可溶有机质也较低,生烃潜力小,为无效烃源岩。优质烃源岩生物标志化合物中富含植烷、C28甾烷、伽马蜡烷和C35藿烷等指示咸水环境的化合物,同时具有高甾烷低藿烷、高C27甾烷低C29甾烷等特征,指示有机质主要来自于水生藻类。这些藻类中富含脂类化合物,被称为"油藻",在较低的成熟演化阶段可直接转化为烃类。咸化环境有利于藻类直接转化而成液态烃的保存,从而形成"未熟—低熟油"。柴达木盆地西部咸化湖相烃源岩中所含的"可溶有机质"明显高于淡水湖相烃源岩,这正是该地区在中浅层发现的一批"未熟—低熟油田"的重要物质来源。通过模拟实验证实,有机质在成熟演化阶段也具有较高的生油潜力,符合经典的油气生成模式。因此,对于深层来说,成熟的烃源岩形成的油气是主要的勘探对象。在该地区古近系深层优质烃源岩形成的油气具有2类成藏模式:(1)源外成藏,即通过油源断层将油气运移至浅部构造圈闭聚集成藏;(2)源内成藏,即在深部烃源岩附近的岩性圈闭中近源聚集。目前这2类油气藏勘探均已获得重大突破,发现了2个亿吨级储量区块,证实深部优质烃源岩形成的油气藏勘探潜力巨大。     

塔里木盆地三叠系有利生烃环境

塔里木盆地三叠系暗色泥岩分布广、厚度大、有机碳和可溶有机质含量高。烃源岩可溶抽提物中含有很高的孕甾烷、升孕甾烷和丰富的长链三环二萜烷 ,说明三叠系烃源岩母质组成中含有丰富的低等水生生物成分 ,非常有利于油气的形成。三叠系烃源岩在塔里木盆地多数地区已成熟。油气源对比结果表明 ,塔里木盆地目前所产的原油和天然气中有相当一部分均与三叠系烃源岩有关 ,三叠系地层具有较高的生油气潜力。     

Source Rock Characterization Within the Stratigraphic Settings of the Orange Basin,South Africa

abstract

The petroleum source rock potential of different system tracts of a Cretaceous unit of the Orange Basin, South Africa, was evaluated using Rock-Eval pyrolysis. Forty rock samples from eight wells were obtained within the systems tract, Lowstand System Tracts (LST), Transgressive System Tracts (TST), and Highstand System Tracts (HST), in the basin. The results revealed that LST is characterized by mainly marginally organic rich shale samples with a few organic rich rocks, variable organic matter types ranging from Type II to Type IV, and a few samples that are thermally mature but have low organic matter quality. Four samples from two wells (A_F1 and O_A1) in the LST had good petroleum generative potential but were not sufficiently mature for petroleum generation. TST is characterized with a few samples being marginally organic rich, with only one being organic rich, mainly Type III kerogen with few Type IV kerogen, and only a few samples are thermally mature that have low organic matter quality. HST is characterized by many marginally organic rich rock samples, mainly Type III with a few mixed Type II/III kerogen, and only a few samples were thermally mature. The results of this study show that the LST has the best prospect in terms of petroleum generation potential, followed by HST and TST in that order. The study also reveals that limited petroleum source rocks exist, which are also impacted by low thermal maturity levels. The basin is more gas prone than oil.     

Biomarker characteristics and geological significance of middle and upper Permian source rocks in the southeastern Junggar Basin

Total organic carbon content (TOC), carbon isotope and biomarker analysis have been done on the source rocks from Lucaogou and Wutonggou formations in Junggar Basin, NW China. (1) the TOC values of the source rocks are more than 5%, and the kerogen types are type I₁-II, and the organic matters are mainly algae and bacteria, and are in the mature stage. (2) the depositional environments of the source rocks are weak reduction-weak oxidation, and are of weakly salty water to brackish water environment.     

东濮凹陷不同环境烃源岩评价及生排烃特征研究

东濮凹陷不同环境烃源岩生烃潜力差别巨大,文中对不同环境烃源岩有机地球化学特征和生排烃特征进行了研究。研究结果表明:东濮北部咸水环境烃源岩为好—优质烃源岩,北部半咸水环境烃源岩为中等—好烃源岩,南部淡水—微咸水环境烃源岩最差,为差—中等烃源岩。不同环境烃源岩均有2次生烃和2次排烃,第一期生烃为镜质体反射率Ro小于0.7%,该期主要是可溶有机质直接转化成未熟或者低熟油,第二期为Ro大于0.7%,主要以干酪根热降解生成成熟油为主。东濮凹陷不同环境烃源岩评价及生排烃特征的研究,对东濮凹陷下一步勘探具有指导意义。     

Organic Geochemistry of Source Rocks, Condensates, and Thermal Geochemical Modeling of Miocene Sequence of Some Wells, Onshore Nile Delta, Egypt

The organic geochemical and biomarker analyses of the Miocene source rocks of some wells in the onshore Nile Delta, suggested that the Abu Madi Formation has poor immature to marginally mature source rocks of Type III Kerogen deposited under the terrestrial environment. The Sidi Salem Formation has fair-to-good mature source rocks of producing mixed oil and gas, originating mainly from marine organic sources. The Moghra Formation has mature good source rocks for Type (II/III) kerogen, derived from organic matter and rich in both terrigeneous and marine sources. The geochemistry of condensates revealed that the Abu Madi and Moghra condensates originated from marine organic matters with little input from a terrestrial source, while Sidi Salem condensate was derived from more contribution of terrestrial organic matters. Abu Madi condensate is less mature than Sidi Salem and Moghra condensate. The geochemical thermal modeling of the Miocene source rocks indicates that the Abu Madi formations are in the early stages of hydrocarbon up until the present time, while Moghra and Sidi Salem formations are in the mature stage of hydrocarbon generation up until the present time. This indicates that the studied condensates have probably migrated from deeply buried source rocks which are at a higher level of maturity rather than from less mature source rocks in the study area.     

Organic geochemistry of the Upper Triassic–Middle Jurassic Shemshak Group (Alborz Mountains,NE Iran)

Abstract

The organic geochemistry of shale samples of Shemshak Group at Dehmolla section in Eastern Alborz Mountains in the present study are discussed throughout the Rock-Eval pyrolysis. The results used to describe the quantity, type, maturity, and petroleum potentials of the Shemshak Group sediments. The pyrolysis data show that the total organic carbon values of the shale samples are between 0.08 and 20.98?wt% and the generation potential (S1+ S2) of the studied samples ranges from 0.02 to 9.47?mg HC/g rock revealing the organic richness of these samples varies from poor to good. The type of hydrocarbon products (S2/S3) ranging from 0.06 to 2.33 and the type of hydrocarbon determined from Tmax versus HI indicate mainly well for gas generation. Based on the HI versus OI plot diagram, the type III of kerogen is the main type of organic matter in studied samples. These data also show that most of the samples were deposited in oxic environments with low sedimentation rate and high amount of organic matter from the terrestrial source. “Tmax” values ranging from 416?°C to 602?°C in studied samples indicate that most of the samples are over mature and located in gas zone.     

南祁连盆地木里坳陷石炭系-侏罗系天然气水合物气源岩有机地球化学特征

通过开展南祁连盆地木里坳陷天然气水合物基础地质剖面调查工作,对石炭系、二叠系、三叠系、侏罗系共四套层系5条剖面的炭质泥岩、泥岩等样品进行了系统采样与分析,在此基础上深入研究四套层系的有机质丰度、有机质类型和有机质成熟度等地球化学特征,分析及对比各层系的有机地球化学指标,以探讨不同层系烃（气）源岩为天然气水合物提供的气源条件。结果表明：石炭系-二叠系有机质丰度偏低,TOC（总有机碳含量）普遍小于0.4%,为非和差烃源岩,有机质类型主要为Ⅱ型和Ⅲ型,有机质成熟度为过成熟,生烃能力较差,难以成为天然气水合物潜在气源岩。三叠系样品TOC值普遍大于1%,氯仿沥青“A”平均为0.89‰,以很好和好烃源岩为主,并含少量差和非烃源岩,有机质类型以Ⅲ型为主,含少量Ⅱ₂型,镜质体反射率R_o值为0.74%~0.98%,整体上处于成熟阶段,生气能力较强,可作为天然气水合物主要潜在气源岩。侏罗系以很好、好和中等烃源岩为主,并含部分差烃源岩,有机质类型主要为Ⅱ型和Ⅲ型,R_o值为0.62%~0.97%,整体上处于成熟阶段,可作为天然气水合物次要潜在气源岩。     

Geochemical Characterization of Offshore Western Niger Delta Source Rock

Abstract

A geochemical characterization of rock samples obtained from three offshore fields, MJ, MF, and ML, was carried out. Offshore oil and onshore oil samples were also studied for correlation. The gas chromatographic data showed that the three offshore fields studied exhibited different and unique geochemical signatures. Most rock samples from the MJ field have moderate thermal maturity; n-alkane and their isoprenoid hydrocarbon distribution indicated predominant mixed organic matter with some terrestrial organic matter. The organic matters were deposited in alternating oxic and anoxic environments. In the MF field, sedimentation of the organic matter in the shallow depths was under reducing environments, whereas that of the deeper depth horizons was under oxidizing environments. The rock samples in the field had predominant input from marine organic matter with moderate thermal maturity. In the ML field, the geochemical data indicated that oxic conditions prevailed during sedimentation of the organic matter. About half of the rock samples from this field are thermally mature, with almost equal distribution of marine and terrestrial organic facies. Marine organic matter was prevalent in the shallow depth horizons, whereas terrestrial organic matter was prevalent in deeper depth horizons. The offshore oil samples and offshore rock extracts are also correlative. This study indicates that there are two petroleum systems in the offshore western Niger Delta—marine and terrigenous petroleum systems—though the terrigeonous system is more pervasive.     

Tricyclic terpane geochemistry of source rocks from Northwestern and Central Niger Delta

This distribution of tricyclic terpanes in source rocks from the northwestern and central Niger Delta was used to evaluate their origin, depositional environment and thermal maturity. The rock samples were extracted using Soxhlet extraction method and the saturated hydrocarbon fraction was analysed for biomarkers using gas chromatography-mass spectrometry (GC-MS). The values of soluble organic matter (SOM) and total hydrocarbons for wells AW and OP source rock samples exceeded the minimum 500 ppm and 300 ppm, respectively with values indicating very good to excellent potential source rocks. The tricyclic terpane source parameters and the complementary distribution of hopanes, regular C₂₇-C₂₉ steranes, n-alkanes and acyclic isoprenoid hydrocarbons showed that samples from well AW consist of mixed marine/terrestrial organic matter while those from well OP consist of organic matter largely from terrestrial origin. The values of Pr/Ph ratio for source rock samples from wells AW and OP indicate deposition of the organic matter under suboxic conditions. Sterane and hopane biomarker maturity parameters indicated that the source rock samples from wells AW and OP are at onset of oil generation and main oil window, Most of the source rock samples from well AW are more thermally mature than those from well OP. The results of tricyclic terpane maturity parameters indicated low thermal maturity for the rock samples from both wells with samples from well AW more thermally mature than those from well OP.     

Evaluation of the nature,origin and potentiality of the subsurface Middle Jurassic and Lower Cretaceous source rocks in Melleiha G-1x well,North Western Desert,Egypt

The present work aims to evaluate the nature and origin of the source rock potentiality of subsurface Middle Jurassic and Lower Cretaceous source rocks in Melleiha G-1x well. This target was achieved throughout the evaluation of total organic carbon, rock Eval pyrolysis and vitrinite reflectance for fifteen cutting samples and three extract samples collected from Khatatba, Alam El Bueib and Kharita formations in the studied well. The result revealed that the main hydrocarbon of source rocks, for the Middle Jurassic (Khatatba Fm.) is mainly mature, and has good capability of producing oil and minor gas. Lower Cretaceous source rocks (Alam El Bueib Fm.) are mature, derived from mixed organic sources and have fair to good capability to generate gas and oil. Kharita Formation of immature source rocks originated from terrestrial origin and has poor to fair potential to produce gas. This indicates that Khatatba and Alam El Bueib formations take the direction of increasing maturity far away from the direction of biodegradation and can be considered as effective source potential in the Melleiha G-1x well.     

西藏乌郁盆地烃源岩有机地球化学特征研究

乌郁盆地为西藏高原新生代山间盆地,渐新世以来自下而上发育渐新统日贡拉组、中新统芒乡组、上新统嘎扎村组、上新统宗当村组地层,这些地层中均有暗色烃源岩出露。地化分析表明,芒乡组烃源岩有机质类型好、丰度高、生烃潜量大,处于生油高峰期阶段;nC_21-/nC₂₂₊均值为1.2,表明有机质主要来源于水生低等生物;Pr/Ph均值为1.2,表明有机质沉积环境为深湖—半深湖弱还原环境;γ-蜡烷指数较高,均值达到了3.32,说明沉积时期水体出现分层并具有较高的盐度,有利于有机质的保存;芒乡组烃源岩是乌郁盆地的主力烃源岩。芒乡组煤层样品有机质丰度较高,类型以Ⅲ型为主,进入成熟阶段,是良好的气源岩。      

湘中坳陷涟源凹陷烃源岩油气地球化学特征

湘中坳陷涟源凹陷烃源岩类型复杂,包括碳酸盐岩、泥岩和煤层。根据涟源凹陷大量露头样品的残余有机碳含量、氯仿沥青“A”、镜质体反射率和包裹体等地球化学实验数据,分析了泥盆系-二叠系烃源岩的有机质丰度、类型及热演化程度。结果表明涟源凹陷的烃源岩总体演化程度均已达到过成熟阶段,油气资源以干气为主。针对烃源岩样品的热演化程度高、丰度低的特征,在了解烃源岩地球化学特征及其与构造运动匹配关系的基础上,探讨了涟源凹陷二次生烃的可能性,最终认为涟源凹陷泥盆系-二叠系烃源岩具有中等级别的生烃能力,并在二叠系的龙潭组煤层有二次生烃的可能。     

塔里木盆地天然气地球化学特征与成因类型研究

通过统计分析塔里木盆地的234个天然气样品指出：该盆地的天然气主要以烃类气体为主(烃类气体含量为80%以上,占样品总数的84%);古生界和中生界天然气中的非烃气体N₂含量高于新生界,且N₂与烃类气体（C _1-4）之间存在正相关性;古生界和中生界天然气主要为油型气,而新生界天然气则为煤成气,且δ¹³C₂和δ¹³C₃存在一定的正相关性;³He/⁴He值一般为n×10^-8数量级,表现为壳源特征,且³He/⁴He值与天然气类型没有明显关系;古生界和中生界天然气的⁴⁰Ar/³⁶Ar值整体上要略高于新生界(这与形成天然气母质中K丰度有关)。根据以上地球化学参数判定塔里木盆地天然气以有机成因类型为主。     

BIOMARKER GEOCHEMISTRY OF PALEOGENE CRUDE OILS AND SOURCE ROCKS FROM THE RAOYANG SAG,BOHAI BAY BASIN,NE CHINA: AN OIL – SOURCE ROCK CORRELATION STUDY

This study presents a systematic geochemical analysis of Paleogene crude oils and source rocks from the Raoyang Sag in the Jizhong sub-basin of the Bohai Bay Basin (NE China). The geochemical characteristics of fifty-three oil samples from wells in four sub-sags were analysed using gas chromatography (GC) and gas chromatography – mass spectrometry (GC-MS). Twenty core samples of mudstones from Members 1 and 3 of the Eocene-Oligocene Shahejie Formation were investigated for total organic carbon (TOC) content and by Rock-Eval pyrolysis and GC-MS to study their geochemistry and hydrocarbon generation potential. The oils were tentatively correlated to the source rocks. The results show that three groups of crude oils can be identified. Group I oils are characterized by high values of the gammacerane index and low values of the ratios of Pr/Ph, Ts/Tm, 20S/(20S+20R) C₂₉ steranes, ββ/(ββ+αα) C₂₉ steranes, C₂₇ diasteranes/ C₂₇ regular steranes and C₂₇/C₂₉ steranes. These oils have the lowest maturity and are interpreted to have originated from a source rock containing mixed organic matter deposited in an anoxic saline lacustrine environment. The biomarker parameter values of Group III oils are the opposite to those in Group I, and are interpreted to indicate a highly mature, terrigenous organic matter input into source rocks which were deposited in suboxic to anoxic freshwater lacustrine conditions. The parameter values of Group II oils are between those of the oils in Groups I and III, and are interpreted to indicate that the oils were generated from mixed organic matter in source rocks deposited in an anoxic brackish–saline or saline lacustrine environment. The results of the source rock analyses show that samples from Member 1 of the Shahejie Formation were deposited in an anoxic, brackish – saline or saline lacustrine environment with mixed organic matter input and are of low maturity. Source rocks in Member 3 of the Shahejie Formation were deposited in a suboxic to anoxic, brackish – saline or freshwater lacustrine environment with a terrigenous organic matter input and are of higher maturity. Correlation between rock samples and crude oils indicates that Group I oils were probably derived from Member 1 source rocks, while Group III oils were more likely generated by Member 3 source rocks. The Group II oils with transitional characteristics are likely to have a mixed source from both sets of source rocks.     

琼东南盆地渐新统烃源岩微观沉积特征与沉积环境

利用背散射电子成像（BSEI）技术对琼东南盆地渐新统崖城组和陵水组烃源岩微观沉积特征进行了高分辨率研究。结果显示,渐新统烃源岩中的有机质成分既有海相化石,如有孔虫和钙质超微化石,又有丝状或纹层状有机质,还有陆源搬运而来的植物碎屑。这些有机质在烃源岩中的分布极不均匀,有些呈连续纹层状分布,有些呈断续纹层状分布,有些呈分散状均匀散布在矿物颗粒中,还有些则呈团块状或絮凝状分布。根据有机质成分及分布形式,并结合烃源岩沉积结构和构造,将琼东南盆地渐新统烃源岩划分为含连续纹层状有机质泥岩、含断续纹层状有机质泥岩、含有孔虫和钙质超微化石泥岩、含陆源植物碎屑泥岩和含分散状有机质泥岩5种类型。同时,根据钙质超微化石组合变化和微观沉积特征,推测琼东南盆地渐新世总体为滨岸、滨海和浅海沉积环境。     

鄂尔多斯盆地伊陕斜坡长9烃源岩特征与生烃潜力

鄂尔多斯盆地伊陕斜坡发现多个长9烃源岩邻近的下组合含油有利区,为推进该区下组合石油勘探,亟需深化长9烃源岩特征及生烃潜力研究。利用测井、录井和岩心资料,分析研究区长9烃源岩分布特征。应用岩石热解、总有机碳、干酪根显微组分分析及饱和烃色谱-质谱生物标志化合物分析等方法,研究长9烃源岩地球化学特征与生烃潜力。结果表明,长9₁烃源岩在吴起、靖边、志丹、安塞等地区均有分布,厚度最大超20 m。长9₂烃源岩主要发育在甘泉—洛川地区,厚度最大超12 m。长9烃源岩有机质丰度较高,有机质来源于低等水生生物和陆源高等植物。有机质类型以Ⅰ型和Ⅱ₁型为主,处于成熟阶段,烃源岩生烃转化率高、生烃能力较强的区域主要为志丹—安塞地区。长9烃源岩多数为较好—好烃源岩,少数为优质烃源岩,具备较强的生烃能力和排烃能力,为伊陕斜坡延长组下组合石油聚集成藏提供了物质基础。     

MATURATION AND DEPOSITIONAL ENVIRONMENTS OF CRUDE OILS FROM GULF OF SUEZ

ABSTRACT

Crude oil samples from the major producing fields in the Gulf of Suez were geochemically assessed to evaluate maturity, origin and depositional environmental trends. Multiple analytical parameters used to charactrizethe petroleum samples included asphaltene content, sulfur content, liquid chromatographic separation, and gas chromatography of the saturated hydrocarbons fraction. From the results obtained, it was suggested that the crude oils are mature. Also, no strong evidence of biodegradation has been observed. Distribution of n-alkanes indicated that the crude oils are derived mainly from marine sedmentary source rocks. Pristane/phytane ratio of the crude oils seemed to be mostly below unity, indicating reducing depositional environments.     

伊犁盆地二叠系烃源岩沉积环境

据不同岩类烃源岩有机碳含量分布、饱和烃气相色谱及有机质类型等特征,研究了烃源岩的沉积环境,分析了沉积环境对有机质丰度和类型的影响。研究认为,伊犁盆地二叠系烃源岩主要集中在塔姆齐萨依组和巴斯尔干组,沉积时总体具温带气候特征,水体的古盐度较高,水介质条件呈弱碱性-碱性,沉积环境为弱还原-还原相。其中还原程度强、具一定深度水体的沉积相带是原始有机质沉积的良好场所,沉积有机质能及时沉积、保存下来。因此,烃源岩有机质丰度普遍较高,类型好;反之,则明显变差。