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1.
煤系页岩气的基本特点与聚集规律 总被引：1，自引：0，他引：1
煤系页岩气是页岩气的重要类型之一。从煤系岩性组合、煤系页岩气地化特征和盖层条件等方面入手,剖析了煤系页岩气的生、排烃能力及保存条件,总结了中国煤系泥页岩的分布特征与发育规律。研究表明:煤系干酪根以腐殖型(III型)为主,H/C较低,总有机碳TOC值高;生烃母质的性质导致煤系泥页岩以生气为主,且具有长期缓慢生烃、排气态烃困难、滞后,排烃效率低、残留烃量大等特点;煤系中的煤层既是良好的气源岩,又对下伏层位的页岩气起到封盖作用,因此,煤系泥页岩具备较好的聚集成藏潜力。 相似文献
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页岩热演化史与页岩气的成烃、成藏过程关系极为密切.一方面,页岩热演化过程决定了页岩生烃过程、页岩气类型和生气量;另一方面,页岩有机孔隙的形成与页岩热演化过程密切相关.在前期热史恢复基础上,以锆石（U-Th）/He和沥青反射率Rb等古温标进行标定,模拟了川西南地区代表性钻孔下寒武统筇竹寺组页岩热演化史,探讨了页岩热演化过程与页岩气成烃、成藏的关系.研究结果表明,川西南地区下寒武统筇竹寺组页岩热演化过程和生烃史差异性明显,可以识别出两种模式:加里东期坳陷区,筇竹寺组页岩在加里东期成熟,中?晚二叠世期间快速演化定型,两个生烃高峰期分别出现在志留纪（生油高峰?湿气阶段）、中?晚二叠世（干气阶段）,此后再无明显的生烃活动;加里东期古隆起区,筇竹寺组页岩在加里东期未熟?低熟,晚海西期?燕山期持续增熟,亦存在两期生烃高峰,分别是中?晚二叠世（生油高峰阶段）、晚侏罗世?早白垩世（湿气?干气阶段）,筇竹寺组页岩生烃过程持续到晚白垩世末期.分析表明中?晚二叠世期间筇竹寺组页岩的埋深差异造成了其受峨眉山地幔柱热效应的影响不同,进而决定了加里东期坳陷区与隆起区筇竹寺组页岩热演化过程和生烃史差异,并最终导致了威远?犍为地区筇竹寺组页岩含气性优于盆地外围.综合川西南地区筇竹寺页岩生烃史和孔隙度演化模型,将川西南成藏条件相对优越的威远?犍为地区筇竹寺组页岩气成藏过程分为4个阶段:早古生代时期源?储?盖形成和生物气成藏阶段、中?晚二叠世期间初始成藏阶段、晚侏罗世?早白垩世主成藏阶段和晚白垩世以后调整改造阶段.该成果以页岩热演化过程为切入点解释了川西南威远?犍为地区与盆地外围下寒武统筇竹寺组页岩气成藏差异的原因. 相似文献
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安徽阜阳地区位于周口坳陷东部,古生代属于华北地台克拉通盆地,上古生界石炭—二叠系发育了一套三角洲聚煤沉积建造。由于频繁海进海退,砂岩、灰岩与泥岩、煤间互沉积,构成“源—储互层式”生储盖组合,易于形成含页岩气、煤层气、致密砂岩气在内的多烃类相态的非常规油气资源。通过对沉积盆地演化特征的研究,认为研究区所处盆地存在3种类型的演化模式:区域抬升型、持续沉降型和差异沉降型,反映了印支期之后研究区盆地各构造单元演化的差异性,这种差异性对沉积、构造、生烃史等有重要的控制作用。 相似文献
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Coal measure source rocks, located in the Xihu Sag of the East China Sea Shelf Basin, were analyzed to define the hydrocarbon generation potential, organic geochemistry/petrology characteristics, and coal preservation conditions. The Pinghu source rocks in the Xihu Sag are mainly gas-prone accompany with condensate oil generation. The coals and shales of the Pinghu Formation are classified from "fair" to "excellent" source rocks with total organic carbon(TOC) contents ranging from 25.2% to 77.2% and 1.29% to 20.9%, respectively. The coals are richer in TOC and S1+S2 than the shales, indicating that the coals have more generation potential per unit mass. Moreover, the kerogen type of the organic matter consists of types Ⅱ-Ⅲ and Ⅲ, which the maturity Ro ranges from 0.59% to 0.83%. Petrographically, the coals and shales are dominated by vitrinite macerals(69.1%–96.8%) with minor proportions of liptinite(2.5%–17.55%) and inertinite(0.2%–6.2%). The correlation between maceral composition and S1+S2 indicates that the main contributor to the generation potential is vitrinite. Therefore, the coals and shales of the Pinghu Formation has good hydrocarbon generation potential, which provided a good foundation for coal measure gas accumulation. Furthermore, coal facies models indicates that the Pinghu coal was deposited in limno-telmatic environment under high water levels, with low tree density(mainly herbaceous) and with low-moderate nutrient supply. Fluctuating water levels and intermittent flooding during the deposition of peat resulted in the inter-layering of coal, shale and sandstone, which potentially providing favorable preservation conditions for coal measure gas. 相似文献
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针对黔西北（贵州毕节）可乐向斜中段晚二叠世含煤地层具有含煤层数多、主力煤层埋藏较深的特点,结合该区探井钻遇致密砂岩气层的实际情况,从沉积环境、储层厚度、源储配置及含气性等方面评价了该区煤层气与致密砂岩气"两气"共探的勘探潜力。研究表明:可乐向斜下煤组和中煤组分别沉积于龙潭早期和晚期,这两个时期地层主要处于曲流河、河控三角洲平原等沉积相带,有利于煤岩与致密砂岩储层的形成;龙潭组中煤组煤层和致密砂岩层分布较稳定,累积厚度分别在16 m和20 m以上;煤系中煤岩、泥岩、砂岩互层叠置出现,具备良好的源储配置关系,可形成多套"生储盖组合";根据X1井气测录井和测井结果,在煤层和致密砂岩层均显示全烃值异常,煤层段异常值最大可达78.35%,钻遇的两层致密砂岩层含气饱和度分别为39.97%和12.79%,说明煤系中有"两气"共存的情况。 相似文献
7.
Tight-sand gas in the Jurassic and shale gas within the fifth member of Xujiahe Formation(T3x5) in the Western Sichuan Basin(WSD) are currently regarded as the most prolific emerging unconventional gas plays in China. This study conducted a conventional evaluation of T3x5 source rocks in the WSD, and investigated their hydrocarbon generation and expulsion characteristics, including intensity, efficiency and amount. The results show that, the T3x5 source rocks are thick(generally 200 m), and have a high total organic content(TOC), ranging from 2.5 to 4.5 wt%. It is thus indivative of a great hydrocarbon generation potential when they underwent high thermal evolution(Ro1.2%) in the area. In addition, an improved method of hydrocarbon generation potential is applied, indicating that the source rocks reached a hydrocarbon expulsion threshold with vitrinite reflectance(Ro) reaching 1.06%, and that the comprehensive hydrocarbon expulsion efficiency is about 60%. The amount of hydrocarbon generation and expulsion from T3x5 source rocks is 3.14×1010 t and 1.86×1010 t, respectively, with a residual amount of 1.28×1010 t within them. Continuous-type tight-sand gas is predicted to have developed in the Jurassic in the Chengdu Sag of the WSD because of the good source-reservoir configuration; the Jurassic sandstone reservoirs are tight, and the gas expelled from the T3x5 source rocks migrates for very short distances vertically and horizontally. The amount of gas accumulation in the Jurassic reservoirs derived from T3x5 source rocks is up to 9.3×108 t. Geological resources of shale gas are up to 1.05×1010 t. Small differences between the amounts calculated by the volumetric method and those obtained by hydrocarbon generation potential method may be due to other gas accumulations present within interbedded sands associated with gas shales. 相似文献
8.
中国非常规油气的战略思考 总被引：1，自引：0，他引：1
本文基于非常规油气的内涵,分析了致密砂岩油气和泥页岩油气的成藏地质条件,论述了非常规油气资源潜力巨大,指明中国非常规油气资源战略发展方向。研究表明,中国非常规油气藏是富集在近源储集体或烃源岩的低孔、低渗的微米级纳米级的储集空间中连续油气聚集,淡化了圈闭、油气藏边界的概念。依据成藏地质条件和油气资源潜力的差异,非常规油气藏主要指致密砂岩油气和泥页岩油气藏。致密砂岩油气藏多位于斜坡、坳陷区,具有广覆式有效烃源岩;源、储关联密切,多呈互层式;油气运移距离短,以非达西渗流为主;储集体渗透率、孔隙度极低。泥页岩油气藏圈闭概念淡化,典型的储源一体;多形成于盆地坳陷或斜坡区,泥页岩大面积连续分布;有机质丰度大,热演化成熟度高;多发育纹层结构,纳米级孔隙、裂缝储集系统;储集层脆性系数大,地层压力高。烃源岩呈现多时代、多层系、多沉积环境特征,从震旦系到第三系均有富含有机质的烃源岩发育,沉积环境囊括陆相海、陆交互相海相,非常规油气资源潜力巨大。常规与非常规油气在时、空域的紧密伴生和规律聚集,使得常规非常规油气在平面上和纵向上形成“有序聚集”体系。对“有序聚集”的不同类油气藏进行“整一化勘探、整一化部署、整一化开采”,实现常规非常规油气整一化科学有序开发,避免整体油气资源的破坏和遗漏;从而丰富油气地质理论,促进油气勘探由“点带面”向综合有序三维空间迈进。 相似文献
9.
The Upper Paleozoic(Carboniferous to Permian) succession in the east margin of the Ordos Basin in the North China Craton has a potential to contain significant hydrocarbon resources, though attention have been mainly attracted for its successful development of coalbed methane(CBM). To improve the previous resource estimates and evaluate the hydrocarbon play possibilities, this study incorporated new discoveries of hydrocarbon units and their stratigraphic relation with source rocks, hydrocarbon migration and trapping configurations. Continuous hydrocarbon accumulation units were identified within the Upper Paleozoic, including the Taiyuan, Shanxi and Xiashihezi formations with great tight gas potential, and the Taiyuan and Shanxi formations also containing shale gas and CBM. Different strata combinations are identified with coal deposition and favour for continuous gas accumulations, including the tidal flat, deltaic and fluvial systems distributed in most of the study areas. Methane was not only generated from the thick coal seams in the Taiyuan and Shanxi formations, but also from shale and dark mudstones. The coal, shale and tight sandstones are proved of remarkable gas content and hydrocarbon indications, and the gas saturation of tight sandstones decreases upward. The stacked deposit combinations vary isochronally in different areas, while the coal seams were developed stably showing good gas sources. Two key stages control the hydrocarbon enrichment, the continuous subsidence from coal forming to Late Triassic and the anomalous paleo-geothermal event happened in Early Cretaceous, as indicated by the fluid inclusions evidence. Extensive areas show good hydrocarbon development potential presently, and more works should be focused on the evaluation and selection of good reservoir combinations. 相似文献
10.
根据储层的成岩序次、油气包裹体特征及含烃盐水包裹体均一温度,自生伊利石K-Ar同位素年龄,结合构造热演化史及裂变径迹资料,对沁水盆地石炭—二叠系煤层及顶板砂岩煤层气成藏期次进行了综合研究。认为该气藏主要有两大油气充注过程:第一期发生在三叠纪末—早侏罗世,山西组、太原组主力煤层普遍处于成熟阶段,主要生成液烃、气液烃包裹体;第二期发生在晚侏罗世—早白垩世,对应于干酪根裂解气阶段,为煤层气大量生成阶段,是石炭—二叠系煤层气的主要成藏期。山西组顶板砂岩样品自生伊利石年龄约为191Ma,表明早侏罗世,伴随盆地抬升,从煤层中解吸附的油气向砂岩储层充注的最早时间。 相似文献
11.
鄂尔多斯盆地上古生界具有煤层气和致密砂岩气成藏的有利条件。上古生界煤层气与致密砂岩气具有相同的烃源岩,且煤层与致密储层垂向上相互叠置,为二者联合勘探开发奠定了地质基础。在综合考虑煤层气与致密砂岩气成藏地质条件的基础上,建立了鄂尔多斯盆地煤层气与致密砂岩气共同勘探选区的评价指标体系,包括煤层厚度、烃源岩热演化程度、生气强度以及致密储层厚度4个指标。依据建立的评价指标体系,对鄂尔多斯盆地内5个区块进行煤层气与致密砂岩气共同选区评价,评价结果为区块Ⅱ、Ⅲ和Ⅴ为勘探目标区,主要分布在盆地的东西缘,煤层厚度大、烃源岩生气强度大,勘探前景好;区块Ⅰ和Ⅳ为勘探有利区,呈条带状分布在盆地的东北部和西北部,煤层气与致密砂岩气协同勘探潜力较大。 相似文献
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为了评价豫东地区煤系烃源岩生烃潜力,基于有机碳含量（TOC）、镜质体反射率、干酪根类型及显微组成等测试分析结果,探讨了豫东地区不同区块煤系烃源岩的有机地球化学特征,对比分析了不同区块煤系气资源潜力,提出煤系气勘探有利区块。结果表明:区内煤系烃源岩的有机碳含量偏低（小于1.5%）;干酪根类型以Ⅲ型为主,偶见Ⅱ2型干酪根,利于生气;煤系经历了中二叠-中晚三叠世和晚侏罗-早白垩世2个大量生烃阶段,烃源岩热演化程度较高,镜质体反射率（Rran）为1.44%~3.80%,平均2.83%,有机质进入高成熟-过高成熟阶段,生烃量较充足。总体上,区内烃源岩生烃潜力属于差-中级别,砂泥岩储集性能相对较好,含气量高。煤系盖层主要为封盖性好的细砂岩、煤层、泥质岩类,煤系烃源岩气体保存条件好。研究认为研究区的睢西区块烃源岩具有埋藏深度较浅、有效厚度大、孔隙度高、含气量和含气饱和度高、有机质成熟度高的特点,为豫东煤系气勘探的有利区块。 相似文献
13.
柴达木盆地北缘侏罗系页岩油气成藏条件地质地球化学分析 总被引：3，自引：0，他引：3
基于柴达木盆地北缘侏罗系中下统富有机质泥页岩厚度、有机地化特征、物性及泥页岩含油气性等的分析研究,探讨了该地区页岩油气成藏的地质条件,对有利的勘探层段和区带进行了预测。结果表明,柴达木盆地北缘湖西山组和大煤沟组富有机质泥页岩厚度大,有机碳含量多在1.5%以上;有机质类型主要为Ⅱ和Ⅲ型;有机质成熟度从未成熟至过成熟皆有;泥页岩中脆性矿物含量约占50%,孔隙度多在1%~8%之间,孔隙类型多样。湖西山组和大煤沟组泥页岩显示出较强的吸附气体能力,多口钻井在泥页岩段存在明显全烃异常。综上表明,柴达木盆地北缘地区湖西山组、大煤沟组2个层位具备形成页岩油气的地质条件,其中湖西山组中上部泥页岩段为页岩油气有利层段,有利区在冷湖4号-5号构造一带;大煤沟组五段为页岩气有利层段、大煤沟组七段为页岩油有利层段,有利区分布于苏干湖坳陷、鱼卡断陷、红山断陷、欧南凹陷和德令哈断陷东部、南部区。 相似文献
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QI Yu JU Yiwen MENG Shangzhi YU Kun LI Wuyang JIA Tianrang WU Jianguang CHEN Wangang LUO long 《《地质学报》英文版》2020,94(2):430-443
Tight sandstone gas in the Linxing Block, eastern Ordos Basin, has been successfully exploited. The high performance is mainly a result of the special geological conditions. The key geological controls for high production have been discussed on the basis of seismic data, field observation, sample features, mercury porosimetry, mechanical properties, and basin modeling. Firstly, the coal measures have good gas generation potential, not only because of the existence of coalbeds and organic-rich shales, but also because coal laminae and microbial mats in the shales significantly increase their total organic carbon(TOC) contents. Secondly, except for the uplifted zone of the Zijinshan complex and the eastern fault zone, rare large faults develop in the Carboniferous–Permian sequence, ensuing the sealing capacity of cap rock. Small fractures generally concentrated in the sandstones rather than the mudstones. Thirdly, gas accumulation in the Linxing Block was controlled by the tectonic, burial and thermal histories. Gas accumulation in the Linxing Block started in the Late Triassic, followed by three short pauses of thermal maturation caused by relatively small uplifts;the maximum hydrocarbon generation period is the Early Cetaceous as a combined result of regional and magmatic thermal metamorphisms. Field profiles show abundant fractures in sandstone beds but rare fractures in mudstone beds. Mechanical properties, determined by lithostratigraphy, confine the fractures in the sandstones, increasing the permeability of sandstone reservoirs and retaining the sealing capacity of the mudstone cap rocks. The modern ground stress conditions favor the opening of predominant natural fractures in the NNW-SSE and N-S directions. These conclusions are useful for exploring the potential tight sandstone gas field. 相似文献
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鄂尔多斯盆地海陆过渡相富有机质泥页岩特征及页岩气意义 总被引：3，自引：0，他引：3
以鄂尔多斯盆地石炭系-二叠系海陆过渡相富有机质泥页岩为研究对象,通过岩石热解分析、岩石抽提和族组分分析、有机元素分析以及煤岩光学分析等方法,对泥页岩中有机质丰度、类型、热成熟度、生烃潜力等地球化学特征参数进行测试;利用扫描电镜、X射线衍射、物性测试等手段,对泥页岩中矿物组成、孔渗特征等储层评价参数进行分析。研究结果表明：鄂尔多斯盆地海陆过渡相地层中泥页岩分布广泛,埋藏偏深,单层厚度较薄,但累计厚度大;泥页岩中有机碳(TOC)含量平均为2.5%,丰度较大;有机质母质中干酪根类型主要为Ⅲ型;镜质体反射率(Ro)平均为1.2%,热演化程度达到中高成熟阶段;具有较大的生烃潜力(S1+S2);同时,石英、长石等脆性矿物含量较高;发育多种孔、缝类型;保存条件良好,为页岩气提供有利的成藏环境。 相似文献
16.
目前针对桂中坳陷早石炭世富有机质泥页岩的生烃潜力方面研究很少,严重制约了该区以页岩气为主的非常规油气勘探.本研究对鹿寨县城西石炭系鹿寨组泥页岩系统取样分析,从有机碳含量、岩石热解、有机碳同位素组成、抽提物正构烷烃组成特征及泥岩镜质体反射率多个方面讨论了该套泥页岩的生烃潜力;结合区域构造演化史总结了与下石炭统岩关阶泥页岩密切相关的3种近源气藏赋存模式.研究结果表明:泥页岩的TOC值分布于0.25%~15.67%,其中强制海退前沉积的泥页岩富含有机质,TOC值均大于2%,TOC值与氯仿沥青"A"、生烃潜量及总烃呈弱正相关关系.泥页岩的有机质类型主体为Ⅱ型;泥页岩的Ro值分布于1.72%~2.78%,处于过成熟阶段.泥页岩上下岩性组合特征及桂中坳陷现今所处的构造位置表明,坳陷中部对冲构造区为有利的近源气藏形成区,背冲构造区为较差区;坳陷边缘逆冲推覆构造区为存在岩性圈闭的近源气藏形成区. 相似文献
17.
页岩气是重要的非常规天然气资源,主要以游离气与吸附气状态赋存于页岩中,研究和阐明其含量、主控因素和演化规律对于揭示页岩气成藏机理具有重要意义.采用不同条件下页岩高温高压等温吸附实验、FE-EM、CO2吸附、N2吸附、压汞等实验方法综合研究页岩气藏中的游离气与吸附气的主控因素.结果表明,游离气主要受页岩孔隙类型、孔隙结构、储层温度与压力等条件控制;OC、成熟度和水分影响吸附气含量.基于吸附气体积校正、地质模型和数值计算综合表征,五峰-龙马溪组页岩中以游离气为主,其平均含量约为%,吸附气含量约为4%.在抬升阶段,储层温度和压力发生改变,页岩气赋存形式随之变化,游离气减少,吸附气增加. 相似文献
18.
鄂尔多斯盆地中部上古生界山西组页岩储层特征 总被引：4，自引：1，他引：3
鄂尔多斯盆地山西组发育一套厚度大且有勘探潜力的陆海陆过渡相页岩。应用岩芯观察、X衍射、扫描电镜和显微镜观察以及高压压汞等方法,对该盆地中部山西组页岩的岩石学、矿物学、页岩储集空间、孔隙结构和物性特征进行分析研究。结果表明:研究区山西组页岩以黑色泥岩、黑色页岩夹纹层或薄层状深色粉砂岩为主,页岩主要由黏土矿物和石英两类矿物组成,二者平均含量分别为59.6%和36.9%。页岩宏观和微观裂隙发育,显微镜下统计的显微裂缝平均面密度达到116.6/m。除了发育与矿物和成岩作用有关的矿物孔隙外,页岩中有机显微组分发育较多的有机质孔。页岩孔隙度平均为0.77%,渗透率平均为0.06×10-3 μm2。山西组页岩总有机碳（TOC）、镜质体反射率（Ro,%）和黏土矿物含量是影响页岩孔隙度的主要因素,具有正相关性,而石英含量与页岩孔隙度呈一定的负相关关系。山西组页岩中裂缝的普遍发育提高了页岩的渗透率,有利于页岩气聚集成藏。综合分析表明山西组页岩气储层地质条件一般,开发难度较大,但在裂缝发育、物性较好的层位和地区仍具有较好的页岩气资源前景。 相似文献
19.
川西坳陷深层叠复连续型致密砂岩气藏成因及形成过程 总被引：1，自引：0，他引：1
川西坳陷深层上三叠统须家河组发育典型的致密砂岩气藏,由于该气藏多期构造演化、多期生排烃过程、多期成藏及储层致密化过程复杂的特点,其成因类型和成因机制经过多年的勘探和研究仍然存在争议。文章在剖析典型气藏的基础上,结合研究区构造演化、烃源岩生排烃史和储层致密化过程的研究,综合判识了致密气藏的成因类型,并分析其成因机制。研究结果表明：川西坳陷深层须家河组致密砂岩气藏具有“叠复连续资源潜力大、构造高点低点富气共存、高孔低孔储层含气共存、高压低压气层共存、气水分布复杂”的地质特征。目前气藏的成因类型为“后成”型致密气藏与“先成”型致密气藏的叠加复合型,属叠复连续型致密气藏。川西坳陷深层须家河组演化过程中存在浮力成藏下限和成藏底限,致密砂岩气藏形成和演化受控于2个界限控制下的3个流体动力场的分布和演化。叠复连续型致密砂岩气藏成藏过程可划分为4个阶段：①三叠纪沉积初至三叠纪末,初期天然气成藏条件准备阶段;②三叠纪末至中侏罗世末,早期常规气藏形成阶段;③中侏罗世末至晚侏罗世末,“先成”型致密气藏与“后成”型致密气藏形成阶段;④早白垩世至今,叠复连续型致密油气藏形成及改造阶段。 相似文献
20.
围绕长江经济带清洁能源体系建设对页岩气突破的重大需求，在充分整合长江下游地区以往地质和物探资料的基础上，系统开展了1:25万页岩气基础地质调查，在苏皖南沿江坳陷带、江西萍乐-浙江钱塘坳陷带、南华北地区"两带一区"实施了10口页岩气调查井，基本查明了主要工作区古生界二叠系、志留系、奥陶系、寒武系富有机质泥页岩成藏地质条件，有9口井分别在三叠、二叠、志留、寒武系4套层系获得页岩气、致密砂岩气、煤层气、页岩油、裂缝性砂岩油、裂缝性灰岩油"三气三油"的重要新发现，深化了二叠系和志留系成藏地质认识，探索了三叠系、奥陶系和寒武系含油气性，开辟了新区新层系，揭示了下扬子及南华北中—古生界油气页岩气资源勘查潜力。圈定了10个远景区，初步评价了9个远景区主要目标层的远景资源量，解决了资源前景问题；讨论了制约下扬子页岩气调查突破的卡脖子问题，提出了下一步突破的方向。 相似文献