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1.
珠-坳陷古近纪陆相湖盆发育优质烃源岩,通过对文昌组、恩平组泥岩系统取样,进行常量、微量元素、同位素含量等分析,优选出对环境敏感的元素与元素比值,系统分析了珠-坳陷烃源岩形成时的古环境,包括古盐度、古水深、氧化还原条件、古气候及古水体的封闭性,并建立了有机碳与环境敏感元素比值的定量关系。开展优质烃源岩发育的水化学性质研究,明确研究区优质烃源岩形成演化所具有的古环境特征,最终探讨了文昌组优质烃源岩的发育模式。研究结果表明,珠-坳陷(除韩江凹陷无样本点)文昌期温暖略干气候条件下,湖盆水体主要为淡水-微咸水,发育中-深湖相,整体表现为开放-半封闭、还原—强还原的环境,极利于有机质的保存和优质烃源岩的发育,各凹陷古环境差异不大。烃源岩质量与咸度、水深、还原条件呈正相关,共同影响了优质烃源岩的发育。总之,温暖略干、微咸、深水及强还原、开放-半封闭环境共同控制了珠-坳陷优质烃源岩的发育。 相似文献
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珠江口盆地珠一坳陷惠州26洼为典型的断陷盆地,是已证实的富生烃洼陷。以往对优质烃源岩的研究主要集中在其盆地内部,而对湖盆边缘次洼的烃源岩特征及形成机制鲜有报道。为弥补以往研究的空白,选择惠州26洼东北次洼作为研究区,根据最新的地震、地化和元素分析等资料,对该次洼的烃源岩地化特征和形成机制进行详细研究。结果表明,该次洼文四段发育优质烃源岩,有机质丰度高,含量均值为4.59%,可达“好—很好”烃源岩标准,有机质类型为Ⅰ—Ⅱ1型,以生油为主。文四段沉积时期,惠州26洼东北次洼强烈断陷,形成“洼缘深盆”,且陆源碎屑物质输入量少,为烃源岩发育提供有利的沉积环境,同期火山活动提供了丰富的无机营养物质,形成咸水环境,引起浮游生物勃发,促进有机质的规模形成和保存。综合分析认为,惠州26洼东北次洼文四段优质烃源岩的发现,将优质烃源岩分布范围扩大至湖盆边缘,为该洼陷未来勘探发现奠定生烃基础,对其他地区断陷盆地边缘洼陷评价和勘探潜力分析具有重要的借鉴意义。 相似文献
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兰蕾李友川孙玉梅 《海洋地质与第四纪地质》2016,(5):121-129
通过热解、干酪根显微组分、色谱-质谱、孢粉与藻类分析,认为白云凹陷有机质来源以陆源高等植物为主。烃源岩的发育、质量与分布严格受沉积相控制,恩平组时期的三角洲平原亚相和浅海相发育以陆源高等植物贡献为主、丰度高的好烃源岩,其中,浅海相烃源岩有机质来源中,藻类贡献较三角洲平原亚相略高;珠海组时期的三角洲前缘亚相和半深海相分别发育以陆源高等植物贡献为主、丰度中等的烃源岩和陆源高等植物为主、有机质丰度低的差烃源岩。 相似文献
4.
通过汇总全球几个主要的优质海相烃源岩的古海洋-古气候特征以及相应的沉积环境,从有机质的生产、来源和保存条件3个维度将海相烃源岩发育的古海洋模式概括为:①三角洲-陆源海相模式,如西非陆缘盆地发育的烃源岩;②强蒸发-上升流模式,如墨西哥湾中生界烃源岩;③滞留静海-湿润气候模式,如北海盆地钦莫里阶烃源岩。结合现有资料分析认为,南海北部深水区恩平-珠海组(始新统—渐新统)处于半封闭局限海环境,普遍发育三角洲沉积体系,陆源有机质供应充足,气候条件适宜,具备发育优质海相烃源岩的古海洋条件。 相似文献
5.
《海洋地质与第四纪地质》2016,(5)
通过热解、干酪根显微组分、色谱-质谱、孢粉与藻类分析,认为白云凹陷有机质来源以陆源高等植物为主。烃源岩的发育、质量与分布严格受沉积相控制,恩平组时期的三角洲平原亚相和浅海相发育以陆源高等植物贡献为主、丰度高的好烃源岩,其中,浅海相烃源岩有机质来源中,藻类贡献较三角洲平原亚相略高;珠海组时期的三角洲前缘亚相和半深海相分别发育以陆源高等植物贡献为主、丰度中等的烃源岩和陆源高等植物为主、有机质丰度低的差烃源岩。 相似文献
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利用最新的三维地震、钻井、测井、烃源岩和原油分析化验等资料,对庙西北洼烃源岩地球化学指标、分布特征及成因环境进行了分析,借助盆地模拟和油源对比结果,明确了庙西北洼的主力烃源岩层系和勘探潜力。研究认为:庙西北洼发育东营组和沙一二段2套烃源岩,其中沙一二段烃源岩有机质类型好、丰度高、有机质成熟度高,为好—很好烃源岩,其排烃量占洼陷总排烃量的56%,是庙西北洼的主力烃源岩。油源对比结果表明,PL15-2亿吨级大油田的原油来自沙一二段烃源岩,进一步佐证了沙一二段为主力烃源岩,也预示了庙西北洼具有良好的勘探潜力。 相似文献
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南黄海海域广泛分布了海相古生界,区域地质研究表明,南黄海海相古生界主要发育4套烃源岩层系,分别为下寒武统幕府山组泥质烃源岩,上奥陶统-下志留统五峰组-高家边组泥质烃源岩,下二叠统栖霞组灰质烃源岩和上二叠统龙潭-大隆组泥质烃源岩。通过对这4套烃源岩沉积特征及地球化学实验数据分析,开展了烃源岩地化特征和生烃潜力的评价。评价结果认为,下寒武统幕府山组、下二叠统栖霞组烃源岩有机质丰度高,类型好,生烃潜力高,为好-最好烃源岩;上二叠统龙潭组、大隆组烃源岩,其有机质丰度高,但有机质组成以陆源有机质为主,为较好烃源岩;奥陶-志留系为一般烃源岩,在此基础上,计算南黄海地区的天然气资源量为2.75万亿m~3。 相似文献
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南黄海盆地二叠系烃源岩的生烃层系多、热演化程度高、沉积环境变化大，前人极少从生物标志化合物的角度探讨烃源岩的差异。本文通过对CSDP-2井二叠系16个成熟-过成熟烃源岩样品进行有机地球化学分析，剖析了四套烃源岩的饱和烃、芳香烃馏分中生物标志化合物的组成、演化规律及地质意义。结果表明，二叠系不同层系烃源岩的甾烷系列、三芳甾烷系列、烷基二苯并噻吩系列化合物和β-胡萝卜烷的相对丰度具有显著差异，据此可将其分为栖霞组下段和龙潭组-大隆组泥岩、栖霞组上段和孤峰组硅质岩、孤峰组硅质泥岩3类烃源岩。研究显示，栖霞组下段和龙潭组-大隆组泥岩烃源岩沉积于淡水氧化或微咸水贫氧环境，有机质来源于浮游生物和陆生高等植物；栖霞组上段-孤峰组烃源岩沉积于还原咸水或静水硫化环境，其中硅质岩烃源岩的有机质来源于浮游生物和硅藻，硅质泥岩烃源岩的有机质来源于浮游生物、硅藻和陆生高等植物。此外，甲基菲指数、烷基二苯并噻吩参数（4-MDBT/DBT、MDBI、4,6-/1,4-DMDBT）可作为上二叠统烃源岩的成熟度指标，但不能作为中—下二叠统烃源岩的成熟度指标。 相似文献
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生烃是岩石中所含的有机质产生流体有机化合物的化学反应。岩石有机质化学反应存在两种系统：封闭系统和开放系统，随着埋深加大，烃源岩越来越致密，岩石的化学反应逐渐由开放系统转变为封闭系统。目前的生烃理论仅仅是开放系统下烃源岩成熟与生烃理论，烃源岩成熟与生烃是不匹配的。封闭系统下烃源岩成熟与生烃是不匹配的，烃源岩成熟但不生烃，而是形成另外一种成熟的固体有机质。大多数情况是烃源岩为半封闭系统，烃源岩处于欠生烃状态。构造运动形成的断层和裂隙将烃源岩与疏导层沟通，烃源岩迅速由封闭、半封闭系统转变为开放系统。这种生烃系统的转变形成短时间内过量生烃，笔者将这种生烃作用命名为构造生烃，意味着构造运动期即为主生烃期，伴随着多次构造运动可以形成多个幕式生烃高峰。构造生烃理论开拓两个极其重要的勘探领域：第一，新构造勘探。以往认为已经过了生、排烃期的构造得以解放，如渤海湾郯庐断裂带第四纪圈闭不是过了主生烃期，而是正处于构造生烃的过生烃高峰期。以PL19-3为代表的油气运聚强度只有构造生烃能够解释；第二，超深勘探，特别是天然气勘探。深层勘探的下限将大大延伸，生烃门限，特别是生气门限将大大加深，仅生烃而言万米都不是天然气勘探的极限。 相似文献
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华南陆缘出露的上三叠统-白垩系,累计厚度超过10 000m,露头调查未见油苗,烃源岩主要为泥岩、碳质泥岩和煤线,有机质类型以Ⅱ-Ⅲ型为主。上三叠统小水组,发育较深水的海相、Ⅱ型良好烃源岩,TOC为1.17%～5.43%;下侏罗统桥源组发育海陆过渡环境的Ⅲ型良好烃源岩,TOC为1.36%～10.37%;下侏罗统其他层系(金鸡组、银瓶山组、上龙水组、长埔组、吉水门组)发育浅海-半深海相的中等-好的烃源岩,TOC为0.5%～1.76%。烃源岩均已处于成熟-过成熟阶段。小水组、蓝塘群烃源岩品质良好,厚度巨大,在南海北部海域开展中生界烃源岩研究时,值得重点关注是否有与之相当的烃源岩层系发育。 相似文献
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Significant oil and gas accumulations occur in and around Lougheed Island, Arctic Canada, where hydrocarbon prospectivity is controlled by potential source rock distribution and composition. The Middle to Upper Triassic rocks of the Schei Point Group (e.g. Murray Harbour and Hoyle Bay formations) contain a mixture of Types I and II organic matter (Tasmanales marine algae, amorphous fluorescing bituminite). These source rocks are within the oil generation zone and have HI values up to 600 mg HC/g Corg. The younger source rocks of the Lower Jurassic Jameson Bay and the Upper Jurassic Ringnes formations contain mainly gas-prone Type II/III organic matter and are marginally mature. Vitrinite reflectance profiles suggest an effective geothermal gradient essentially similar to the present-day gradient (20 to 30°C/km). Maturation gradients are low, ranging from 0.125 to 0.185 log%Ro/km. Increases in subsidence rate in the Early Cretaceous suggest that the actual heat flow history was variable and has probably diminished from that time. The high deposition rates of the Christopher Formation shales coincide with the main phase of rifting in Aptian-Albian times. Uplift and increased sediment supply in the Maastrichtian resulted in a new sedimentary and tectonic regime, which culminated in the final phase of the Eurekan Orogeny. Burial history models indicate that hydrocarbon generation in the Schei Point Group took place during rifting in Early Cretaceous, long before any Eurekan deformation. 相似文献
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Potential source rocks on the Laminaria High, a region of the northern Bonaparte Basin on the North West Shelf of Australia, occur within the Middle Jurassic to Lower Cretaceous early to post-rift sequences. Twenty-two representative immature source rock samples from the Jurassic to Lower Cretaceous (Plover, Laminaria, Frigate, Flamingo and Echuca Shoals) sequences were analysed to define the hydrocarbon products that analogous mature source rocks could have generated during thermal maturation and filled the petroleum reservoirs in the Laminaria High region. Rock-Eval pyrolysis data indicate that all the source rocks contain type II–III organic matter and vary in organic richness and quality. Open system pyrolysis-gas chromatography on extracted rock samples show a dominance of aliphatic components in the pyrolysates. The Plover source rocks are the exception which exhibit high phenolic contents due to their predominant land-plant contribution. Most of the kerogens have the potential to generate Paraffinic–Naphthenic–Aromatic oils with low wax contents. Bulk kinetic analyses reveal a relatively broad distribution of activation energies that are directly related to the heterogeneity in the kerogens. These kinetic parameters suggest different degrees of thermal stability, with the predicted commencement of petroleum generation under geological heating conditions covering a relatively broad temperature range from 95 to 135 °C for the Upper Jurassic−Lower Cretaceous source rocks. Both shales and coals of the Middle Jurassic Plover Formation have the potential to generate oil at relatively higher temperatures (140–145 °C) than those measured for crude oils in previous studies. Hence, the Frigate and the Flamingo formations are the main potential sources of oils reservoired in the Laminaria and Corallina fields. Apart from being a reservoir, the Laminaria Formation also contains organic-rich layers, with the potential to generate oil. For the majority of samples analysed, the compositional kinetic model predictions indicate that 80% of the hydrocarbons were generated as oil and 20% as gas. The exception is the Lower Cretaceous Echuca Shoals Formation which shows the potential to generate a greater proportion (40%) of gas despite its marine source affinity, due to inertinite dominating the maceral assemblage. 相似文献
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The Unst Basin is situated in the northern North Sea between the East Shetland Basin and the Shetland Isles. The basin is essentially a three-armed, Permo-Triassic fault-controlled basin containing up to 3600 m of red-beds. This is overlain by a westerly thickening Jurassic and early Cretaceous sequence, the stratigraphy of which is very similar to that of the East Shetland Basin. In particular, the Brent Group (140 m), Humber Group (685 m) and Cromer Knoll Group (300 m) are well represented.As a result of Laramide uplift of the area, the thick Upper Cretaceous and Palaeocene strata of the East Shetland Basin are absent from the Unst Basin. This uplift resulted in substantial erosion within the Unst Basin providing the major source for Palaeocene sands in the Viking Graben and the Faeroes Basin. Late Palaeocene and younger Tertiary strata transgress westwards across this erosion surface.Petroleum exploration within the basin culminated in the drilling of two exploration wells. These wells encountered potential reservoir and source rocks in the Jurassic section. However, geochemical analyses indicate these source rocks are immature for hydrocarbon generation within the Unst Basin. It is concluded that the Unst Basin has a low petroleum potential. 相似文献
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《Marine and Petroleum Geology》2012,37(1):13-34
Structured organic matters of the Palynomorphs of mainly dinoflagellate cysts are used in this study for dating the limestone, black shale, and marl of the Middle Jurassic (Bajocian–Bathonian) Sargelu Formation, Upper Jurassic (Upper Callovian – Lower Oxfordian) Naokelekan Formation, Upper Jurassic (Kimeridgian and Oxfordian) Gotnia and Barsarine Formations, and Upper Jurassic – Lower Cretaceous (Tithonian-Beriassian) Chia Gara source rock Formations while spore species of Cyathidites australis and Glechenidites senonicus are used for maturation assessments of this succession. Materials' used for this palynological study are 320 core and cutting samples of twelve oil wells and three outcrops in North Iraq.Terpane and sterane biomarker distributions, as well as stable isotope values, were determined for oils potential source rock extracts of Jurassic-Lower Cretaceous strata to determine valid oil-to-source rock correlations in North Iraq. Two subfamily carbonate oil types-one of Middle Jurassic age (Sargelu) carbonate rock and the other of mixed Upper Jurassic/Cretaceous age (Chia Gara) with Sargelu sources as well as a different oil family related to Triassic marls, were identified based on multivariate statistical analysis (HCA & 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 C28/C29 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.Palynofacies assessments are performed for this studied succession by ternary kerogen plots of the phytoclast, amorphous organic matters, and palynomorphs. From the diagram of these plots and maturation analysis, it could be assessed that the formations of Chia Gara and Sargelu are both deposited in distal suboxic to anoxic basin and can be correlated with kerogens classified microscopically as Type A and Type B and chemically as Type II. The organic matter, comprised principally of brazinophyte algae, dinoflagellate cysts, spores, pollen, foraminifera test linings, and phytoclasts in all these formations and hence affected with upwelling current. These deposit contain up to 18 wt% total organic matters that are capable to generate hydrocarbons within mature stage of thermal alteration index (TAI) range in Stalplin's scale (Staplin, 1969) of 2.7–3.0 for the Chia Gara Formation and 2.9–3.1 for the Sargelu Formation. Case study examples of these oil prone strata are; one 7-m (23-ft) thick section of the Sargelu Formation averages 44.2 mg HC/g S2 and 439 °C Tmax (Rock-Eval pyrolysis analyses) and 16 wt% TOC especially in well Mk-2 whereas, one 8-m (26-ft) thick section of the Chia Gara and 1-m (3-ft) section of Naokelekan Formations average 44.5 mg HC/g S2 and 440 °C Tmax and 14 wt% TOC especially in well Aj-8. One-dimension, petroleum system models of key wells using IES PetroMod Software can confirm their oil generation capability.These hydrocarbon type accumulation sites are illustrated in structural cross sections and maps in North Iraq. 相似文献
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The Upper Jurassic marlstones (Mikulov Fm.) and marly limestones (Falkenstein Fm.) are the main source rocks for conventional hydrocarbons in the Vienna Basin in Austria. In addition, the Mikulov Formation has been considered a potential shale gas play. In this paper, organic geochemical, petrographical and mineralogical data from both formations in borehole Staatz 1 are used to determine the source potential and its vertical variability. Additional samples from other boreholes are used to evaluate lateral trends. Deltaic sediments (Lower Quarzarenite Member) and prodelta shales (Lower Shale Member) of the Middle Jurassic Gresten Formation have been discussed as secondary sources for hydrocarbons in the Vienna Basin area and are therefore included in the present study.The Falkenstein and Mikulov formations in Staatz 1 contain up to 2.5 wt%TOC. The organic matter is dominated by algal material. Nevertheless, HI values are relative low (<400 mgHC/gTOC), a result of organic matter degradation in a dysoxic environment. Both formations hold a fair to good petroleum potential. Because of its great thickness (∼1500 m), the source potential index of the Upper Jurrasic interval is high (7.5 tHC/m2). Within the oil window, the Falkenstein and Mikulov formations will produce paraffinic-naphtenic-aromatic low wax oil with low sulfur content. Whereas vertical variations are minor, limited data from the deep overmature samples suggest that original TOC contents may have increased basinwards. Based on TOC contents (typically <2.0 wt%) and the very deep position of the maturity cut-off values for shale oil/gas production (∼4000 and 5000 m, respectively), the potential for economic recovery of unconventional petroleum is limited. The Lower Quarzarenite Member of the Middle Jurassic Gresten Formation hosts a moderate oil potential, while the Lower Shale Member is are poor source rock. 相似文献
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通过对南五凹钻井所揭示的阜宁组进行岩性、地球化学、古生物及地震相等综合分析证实,南五凹阜宁组发育中深湖相泥质烃源岩,且该套烃源岩形成于"广湖咸水"沉积环境。"广湖"即湖盆分布广泛,中深湖相泥质烃源岩在凹陷深洼处和缓坡带均有发育,平面上面积大,纵向上厚度大,具备生成油气的物质基础。"咸水"即烃源岩形成时期湖盆受到了海侵影响,致使水体性质偏咸。南五凹与中国东部古新世—始新世期间曾遭受海侵影响的其他湖盆类似,其形成的咸化烃源岩具有"排烃早"的特征。南五凹阜宁组湖相烃源岩"广湖咸水"沉积特征对于油气勘探具有重要意义。 相似文献
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南沙海域礼乐盆地中生界油气资源潜力 总被引：4，自引：0，他引：4
位于南沙东部海域的礼乐盆地是一大型的中、新生代叠置盆地,其特有的地质背景及巨厚的中生代地层显示了其与南沙海域其他新生代沉积盆地的差异。盆地内发育的厚度超过4 000 m的中生代海相地层,主要包括了上侏罗统—下白垩统的滨—浅海相含煤碎屑岩或半深海相页岩、上三叠统—下侏罗统三角洲—浅海相砂泥岩和中三叠统深海硅质页岩等3套地层,展示出盆地具有良好的油气生成潜力。而早期位于华南陆缘、现今位于南沙东部海域的礼乐盆地中生界,完全具备了形成油气藏的基本石油地质条件,具有较为良好的油气资源潜力,其中生界油气资源勘探具有非常重要的意义,将成为我国海域油气勘探的一个重要新领域。 相似文献
20.
Geochemical characteristics of organic matter in the profiles of Dukla, Silesian, Sub-Silesian and Skole units of the Polish Outer Carpathians and of the Palaeozoic–Mesozoic basement in the Dębica-Rzeszów-Leżajsk-Sanok area were established based on Rock-Eval, vitrinite reflectance, isotopic and biomarker analyses of 485 rock samples. The Oligocene Menilite beds have the best hydrocarbon potential of all investigated formations within the Dukla, Silesian, and Skole units. The Ordovician, Silurian, Lower Devonian and locally Middle Jurassic strata of the Palaeozoic–Mesozoic basement are potential source rocks for oil and gas accumulated in Palaeozoic and Mesozoic reservoirs. Thirty one natural gas samples from sandstone reservoirs of the Lower Cretaceous-Lower Miocene strata within the Outer Carpathian sequence and eight from sandstone and carbonate reservoirs of the Palaeozoic–Mesozoic basement were analysed for molecular and isotopic compositions to determine their origin. Natural gases accumulated both in the Outer Carpathian and the Palaeozoic–Mesozoic basement reservoirs are genetically related to thermogenic and microbial processes. Thermogenic gaseous hydrocarbons that accumulated in the Dukla and Silesian units were generated from the Menilite beds. Thermogenic gaseous hydrocarbons that accumulated in the Sub-Silesian Unit most probably migrated from the Silesian Unit. Initial, and probably also secondary microbial methane component has been generated during microbial carbon dioxide reduction within the Oligocene Menilite beds in the Dukla Unit and Oligocene-Lower Miocene Krosno beds in the Silesian Unit. Natural gases that accumulated in traps within the Middle Devonian, Mississippian, Upper Jurassic, and Upper Cretaceous reservoirs of the Palaeozoic–Mesozoic basement were mainly generated during thermogenic processes and only sporadically from initial microbial processes. The thermogenic gases were generated from kerogen of the Ordovician-Silurian and Middle Jurassic strata. The microbial methane component occurs in a few fields of the Dukla and Silesian units and in the two accumulations in the Middle Devonian reservoirs of the Palaeozoic–Mesozoic basement. 相似文献