国外典型煤层气盆地可采资源量计算

随着国内煤层气勘探开发技术的逐渐成熟,国内油气公司开始着眼海外煤层气资源勘探开发。但由于国外煤层气盆地资料匮乏,有效评价其可采资源量是一个难题。选取国外几个典型煤层气盆地,将地质类比法引入煤层气可采资源量估算中。结合煤层气富集成藏的基本要素,依据煤层气盆地实际资料,优选了影响煤层气可采性的10个地质参数作为刻度区和预测区的相似系数,二态定性量化不同地质参数。以等温吸附法确定刻度区的采收率,结合实际采收率经验,采用蒙特卡洛组合抽样估算了可采系数的变化范围。通过对北美、俄乌哈和澳大利亚3个地区10个煤层气盆地的可采资源量计算和对比,发现澳大利亚的鲍恩盆地煤层气可采系数大,可采资源量丰富,具良好的勘探开发潜力。该方法可为国外其他煤层气盆地的可采资源量计算提供借鉴。      

煤层气吸附量动态变化模型研究

基于吸附势理论、气体状态方程,建立了煤储层压力与煤体吸附半径、孔隙半径与煤体吸附量、储层压力与煤体吸附量之间的关系模型,得出储层压力、吸附量、孔隙半径等多参数耦合的煤层气吸附量动态变化模型,利用潘庄区块煤体结构测试数据以及等温吸附试验结果对模型进行了验证。结果表明:潘庄区块以孔径小于7.7 nm的微孔为主,以孔径7.7 nm为临界点孔容呈先减小后增大趋势;模型计算的吸附量动态变化结果与煤体空气干燥基等温吸附变化结果在趋势上具有较高的一致性,模型的起始点为枯竭压力以及枯竭吸附量,得出潘庄区块枯竭吸附量为3 m3/t。模型不仅能够计算地层条件下不同温度和压力共同作用下煤体对甲烷气体的吸附量,且能够预测煤层气排采过程煤层气吸附量的动态变化,有助于确定煤层气排采工作制度以及提高煤层气采收率。      

贵州水城矿区煤层气地质条件与可采潜力分析

水城矿区煤层气资源丰富,在分析矿区煤储层物性和含气性的基础上,估算了煤层气可采性参数,评价了煤层气的可采潜力。结果显示:水城矿区煤层顶、底板以及含煤地层上覆地层均为良好的区域性盖层,煤层气保存条件较好;矿区良好的煤岩、煤质特征和孔隙结构特征为煤层气的大量生成和富集奠定了基础;煤层气理论平均采收率为31.66%,可采资源量为1158×108m3,平均可采资源丰度0.98×108m3/km2,对煤层气开发较为有利;煤层的渗透性较低,可能对煤层气地面排采带来不利影响。建议矿区在煤层气地面开发工作中,注重煤储层渗透性的有效改善,并探讨矿井—地面开发结合的可行性。     

山西省煤层气资源量及可采潜力

山西省煤层气资源丰富,开发条件优越。在以往研究成果的基础上,根据大量的煤田钻孔、煤层气井和煤样等温吸附实验等资料,分析了煤层含气性、煤级、储层压力、温度、煤的吸附能力、含气饱和度等特征,对山西省深部煤层含气量进行了预测,估算了煤层气资源量及可采潜力。研究结果表明,煤级、储层压力、温度、煤的吸附能力、含气饱和度等参数直接或间接受埋深控制,并通过等温吸附方程综合影响深部煤层含气量,含气量随埋深的增加而增加,但增加趋势变缓;估算2000m以浅煤层气资源量约8.3万亿m3,煤层气平均可采系数在30.0%~56.7%。     

淮南矿区剩余煤层气资源可采潜力分析

在分析淮南矿区煤层气地质背景的基础上,采用含量梯度法、压力—吸附法计算了研究区可采煤层的剩余煤层气资源量,探讨了影响该区煤层气可采潜力的煤储层压力、渗透能力、吸附/解吸特征、含气饱和度、可采系数等因素。结果表明,淮南矿区-1 500m以浅剩余煤层气资源量为2 419.70×108m3,可采资源量为1 102.20×108m3,可采资源丰度为1.98×108m3/km2,属于中等储量丰度的大型气田;区内煤储层为正常压力储层,煤储层渗透率、含气饱和度偏低,但本区可采煤层层数多,在渗透率总体偏低的背景下,区内存在的高渗区,具备煤层气地面开采的基础地质条件。     

用典型曲线计算煤层气资源量

参考先进能源公司(ARI)2002年关于粉河盆地煤层气资源评价的研究报告,结合煤层气地质学和煤层气开发理论,提出了一种计算煤层气可采资源量的方法,即使用煤层气典型生产井的产量预测曲线,通过"极限产量"截尾"的方法,计算一评价单元的煤层气可采资源量.并给出了该方法的使用步骤、优点及局限性.     

山西潞安古城井田煤层气资源赋存特征及开发潜力分析

以煤田地质勘查资料为依据,结合井田及周边煤层气勘探成果,研究了古城井田煤层气赋存地质条件,对煤层气资源量及开发条件进行了评价。结果表明：3#煤层平均含气量12.60 m3/t,平均含气饱和度约为67.34%,总体表现为欠饱和-饱和煤储层,区内煤层气预测地质储量为138.64×108m3,资源丰度平均为0.90×108m3/km2,资源富集（资源丰度）表现为西高东低、北高南低的格局;3#煤层可采资源量大,预测煤层气实际采收率为35%~45%,总可采资源量60.49×108m3。     

潞安—晋城矿区煤层气采收率分析

根据煤田地质瓦斯资料和煤层气参数井测试成果，分析了潞安－晋城（新区）矿区主煤储层的平均含气量、饱和度、临界解吸压力、理论采收率以及煤层甲烷解吸率、可解吸量等数据，得出本区主煤储层平均解吸率约为38％，高于全国其它地区。     

混合气体驱替煤层气技术的可行性研究

气体驱替煤层气技术是近年来发展起来的具有温室气体减排和提高煤层气采收率双赢效果的新兴技术,相关研究受到世界主要发达国家的广泛重视。对于温室气体减排的压力,发达国家的研究主要着眼于该技术在高渗透、不可采煤层中的应用,注入气体主要为CO2,目的是尽可能多地封存CO2,同时提高煤层气采收率。目前,国内在这方面的研究刚刚起步。国内煤层具有渗透率普遍较低、不开采煤层与要开采煤层难以界定的特点,注CO2气体驱替煤层气在这种煤层中的可行性值得商榷。针对国内煤层特点和煤矿瓦斯抽采率低的现状,建议采用富N2混合气体驱替煤层气技术,以提高煤层气产采收率。通过理论分析、数值模拟和现场试验研究分析了实施混合气体驱替煤层气技术的可行性。研究结果表明,混合气体驱替煤层气技术适用于国内低渗透、可开采煤层,可以提高煤层气采收率和单产量。     

煤层气损失气量计算的全脱分析法

针对目前煤层气损失气量无法计算煤层的溶解气和游离气含量问题,根据烃类气体进入钻井液的方式和分布状态理论,基于气测录井资料,提出了计算煤层气损失气量的新方法——全脱分析法。通过沁水盆地枣园区块3号煤层的实际应用,发现该方法计算的损失气量明显高于常规煤心样品的回归结果,前者一般为后者的1.5~4.5倍。该方法不仅能有效地解决煤层气损失气量计算中忽视的溶解气和游离气问题,而且还能消除损失时间的影响,同时也可以按不同部位计算煤层气损失气量。该方法适用于不同煤级、各种结构的煤岩,数据易采集,计算过程简单,有很好的应用前景。      

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Late Wuchiapingian (Late Dzhulfian,early Late Permian) limestone olistolites within the Tertiary flysch of Glypia Unit (Mount Parnon,central–eastern Peloponnesus,Greece)

Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.     

PALEONTOLOGY

正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.)     

GEOCHEMICAL EXPLORATION

正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.)     

MICROPALAEONTOLOGY

正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.)     

PETROLOGY

正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus.,     

ENVIRONMENTAL GEOLOGY

正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an     

PROSPECTING EXPLORATION

正20141266Fan Chaoyan(Guangdong Provincial Key Laboratory of Mineral Resources and Geological Processes,Guangzhou 510275,China);Wang Zhenghai On Error Analysis and Correction Method of Measured Strata Section with Wire Projection Method(Journal of