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1.
高、低煤阶煤层气藏地质特征及控气作用差异性研究 总被引:4,自引:0,他引:4
高、低煤阶煤层气地质特征及控气作用差异性是研究煤层气富集成藏的重要组成部分,是煤层气勘探开发理论研究过程中重要的基础性研究领域之一。本文以中国沁水、阜新盆地和美国粉河盆地等典型的含气盆地为例,探讨了高、低煤阶煤层气的储层物性差异,分析了构造控气和水文地质控气作用的差异性。研究表明,高煤阶气藏含气量高,CH4百分含量高,δ13C1值大于-38.75‰,储层渗透率变化小,储层改造难,构造热事件对煤层气的生成、富集贡献大,持续的水动力使气藏遭到破坏,且破坏幅度大,现今地下水格局对气藏的形成具有一定的影响;低煤阶气藏含气量低,CH4百分含量低,δ13C1值大于-49.11‰,储层渗透率变化大,储层易改造,煤热演化史及煤阶影响着煤层气的生成、富集,在煤层气生成过程中活跃的水动力是甲烷生成的主要的水文地质条件之一,但持续的水动力使气藏遭到破坏,且破坏幅度小,而合适的地层水矿化度则是低煤阶煤层气生成的重要条件,地下水格局对气藏的调整和改造起到决定性的影响。 相似文献
2.
Application of MODFLOW and geographic information system to groundwater flow simulation in North China Plain, China 总被引:2,自引:0,他引:2
Shiqin Wang Jingli Shao Xianfang Song Yongbo Zhang Zhibin Huo Xiaoyuan Zhou 《Environmental Geology》2008,55(7):1449-1462
MODFLOW is a groundwater modeling program. It can be compiled and remedied according to the practical applications. Because
of its structure and fixed data format, MODFLOW can be integrated with Geographic Information Systems (GIS) technology for
water resource management. The North China Plain (NCP), which is the politic, economic and cultural center of China, is facing
with water resources shortage and water pollution. Groundwater is the main water resource for industrial, agricultural and
domestic usage. It is necessary to evaluate the groundwater resources of the NCP as an entire aquifer system. With the development
of computer and internet information technology it is also necessary to integrate the groundwater model with the GIS technology.
Because the geological and hydrogeological data in the NCP was mainly in MAPGIS format, the powerful function of GIS of disposing
of and analyzing spatial data and computer languages such as Visual C and Visual Basic were used to define the relationship
between the original data and model data. After analyzing the geological and hydrogeological conditions of the NCP, the groundwater
flow numerical simulation modeling was constructed with MODFLOW. On the basis of GIS, a dynamic evaluation system for groundwater
resources under the internet circumstance was completed. During the process of constructing the groundwater model, a water
budget was analyzed, which showed a negative budget in the NCP. The simulation period was from 1 January 2002 to 31 December
2003. During this period, the total recharge of the groundwater system was 49,374 × 106 m3 and the total discharge was 56,530 × 106 m3 the budget deficit was −7,156 × 106 m3. In this integrated system, the original data including graphs and attribution data could be stored in the database. When
the process of evaluating and predicting groundwater flow was started, these data were transformed into files that the core
program of MODFLOW could read. The calculated water level and drawdown could be displayed and reviewed online. 相似文献
3.
Permo-Carboniferous Radiolarians from the Wupata'erkan Group, Western South Tianshan, Xinjiang, China 总被引:1,自引:0,他引:1
The Wupata‘erkan Group, also called Wupata‘erkan Formation, distributed in the South Tianshan, Xinjiang,China, mainly consists of gray and dark gray fine-grained clastic rocks, interlayered with volcanic rocks, carbonates and cherts. Some ultra-basic rocks (blocks) punctuate the formation. The formation was variously assigned to Silurian-Middle Devonian, Silurian-Lower Devonian, and pre-Devonian, mainly based on Atrypa bodini Mansuy, Hypothyridina parallelepipedia (Brour.) and Prismatophyllum hexagonum Yoh collected from the limestone interlayers, respectively.However, radiolarian fossils obtained from 24 chert specimens of the Wupata‘erkan Group, mainly include Albaillella sp.cf. A. undulata Deflandre, Albaillella sp. cf. A. paradoxa Deflandre, Albaillella cf. A. deflandrei Gourmelon, Albaillella sp. cf. A. indensis Won, Albaillella sp. cf. A. excelsa Ishiga, Kito and Imoto, Albaillella sp. and Latentifistulidae gen. et. sp.indet., are earliest Carboniferous and Late Permian. The earliest Carboniferous assemblage is characterized by Albaillella sp. cf. A. undulata Deflandre, Albaillella sp. cf. A. paradoxa Deflandre, Albaillella cf. A. deflandrei Gourmelon and Albaillella sp. cf. A. indensis Won, and the Late Permian assemblage by Albaillella sp. cf. A. excelsa Ishiga, Kito and Imoto. This new stratigraphic evidence indicates that the Wupata‘erkan Group is possibly composed of rocks with different ages from Silurian to Permian, and therefore, it is probably an ophiolite mrlange. The discovery of Late Permian Albaillella sp. cf. A. excelsa provides more reliable evidence supporting the existence of a Permian relic ancient oceanic basin in the western part of Xinjiang South Tianshan. 相似文献
4.
5.
Shangyue Shen Qinglai Feng Wenqian Yang Zhibin Zhang Chonglakmani Chongpan 《中国地球化学学报》2010,29(3):255-260
On the basis of the petrographic characteristics, rock assemblages, petrochemistry, REEs, trace elements and geotectonic settings, the authors described the characteristics of continental marginal arc-volcanic rocks in the Late Permian-Early Triassic (P2-T1) volcanic rocks distributed on the eastern side of the ocean-ridge/oceanic island basalts in the Chiang Mai belt. The volcanic rock assemblage is basaltic andesite-andesite-rhyolite. The volcanic series is dominated by the calc-alkaline series, with the tholeitic series coming next. The chemical composition of the volcanic rocks is characterized by high Al2O3; the REE distribution patterns are of the LREE-enrichment rightward incline type; the large cation elements are highly enriched, and the volcanic rocks are generally enriched in U and Th and depleted in Ti, Cr and P. The petrochemical plot falls within the field of island-arc volcanic rocks, in consistency with the projected points of continental marginal arc-volcanic rocks in the Lancangjiang belt. These continental mar-ginal arc-volcanic rocks, together with ocean-ridge/oceanic island-type volcanic rocks in the Chiang Mai belt, con-stitute the ocean-ridge volcanic rock-arc magmatic rock belts distributed in pairs, indicative of eastward subduction of the oceanic crust in the Chiang Mai belt. This result is of great importance in exploring the evolution of the pa-leo-Tethys in the Chiang Mai belt. 相似文献
6.
充分利用长江三峡工程文物抢救性发掘的宝贵机会,通过对重庆市忠县中坝遗址、丰都县玉溪遗址等典型遗址和神农架大九湖泥炭地层环境考古研究,摸索出了一套利用年代学、沉积学、重矿物组分鉴定、锆石形态统计、地球化学和环境磁学方法辨别考古遗址地层中古洪水沉积的方法;建立了该区地表孢粉-气候的转换函数,并将其用于对神农架大九湖泥炭地层的研究,弄清了该区全新世以来环境演变的背景,并将自然沉积地层环境演变记录与典型考古遗址地层古洪水事件作了对比分析。遗址时空分布研究表明:长江三峡库区旧石器时代至宋代677处遗址时空分布总趋势是从西往东、从高往低逐渐增加的,遗址多沿江河分布,且在河流交汇处呈聚集状态,这与人类多选择河流1~2级阶地为生、河流交汇处鱼类资源丰富有关。研究表明:中坝遗址能延续5000a的原因一方面与其盐业遗址的属性有关,另一方面与其长期具有良好生态环境有关。从该遗址T0202探方出土近20万件动物骨骼的分类统计证明了这一点。7.6kaBP以来,水位在吴淞高程147.024m以上的古洪水至少在玉溪遗址T0403探方中留下了16次沉积记录。神农架大九湖297cm厚的泥炭及其148个孢粉样品和10个AMS14C测年数据表明,该泥炭地层为本项目提供了理想的全新世自然环境演变背景,尤其8.2kaBP前后的降温事件很明显,6.7~4.2kaBP为中全新世最适宜期,4.2kaBP前后由暖湿转为凉干,3.5~0.9kaBP季风降水整体较弱,0.9kaBP前后转为较凉湿。根据对中坝和玉溪两处遗址地层的研究,在8.2~6.7kaBP期间出现有10个古洪水层;在6.7~4.2kaBP全新世最适宜期遗址地层中出现有8个古洪水层;在3.5~0.9kaBP降水减少的时期,中坝遗址中仅出现2个洪水层(即西周时期的37-1和战国早期的第21层);在0.9kaBP以来降水较多的时期,中坝遗址中存在3个洪水层(即宋代中期的11C-1层、清代的5-1层和1981年的2B-2层)。这表明,8.2~6.7kaBP的洪水在三峡地区次数是最多的,6.7~4.2kaBP的洪水数量次之。长江三峡库区的这一古洪水发生规律或许可以解释长江中游的江汉平原在7.8~5.1kaBP期间遗址数量偏少的原因。 相似文献
7.
滇中地区中元古界"昆阳群"的地层层序是长期争议的重大基础地质问题,在一定程度上制约了地质调查工作的部署及勘查效果,也制约着滇中地区前寒武纪地质研究水平的进一步提高。云南省地质调查院在进行《云南省区域地质志》(第二版、修编)、1:5万二街等4幅区域调查子项目工作中,在前人工作成果的基础上,通过大量的野外地质调查及锆石同位素年代学研究,在滇中地区早前寒武纪地层层序及时代、重大地质事件记录、早期生命与环境协同演化等方面取得了一系列的新发现,具有重要意义。 相似文献
8.
9.
The meta-basic volcanic rocks in the Tengtiaohe Zone yield zircon U–Pb ages of 258.8±2.5 Ma and 259.2±1.8 Ma, respectively which agree with the ages of flood basalts of ELIP and are similar to the basaltic rocks and komatiites from the Song Da Zone in northern Vietnam. The results suggest that the age of meta-basic volcanic rocks is Late Permian, rather than the Early Permian or Early Carboniferous ages as previously inferred. Most meta-basic volcanic rocks are strongly enriched in LREEs relative to HREEs and display trace element patterns similar to the ELIP high-Ti basalts, and are enriched in LILEs with negative Sr anomalies. Their initial ~(87)Sr/~(86) Sr ratios range from 0.705974 to 0.706188 and εNd(t) from-0.82 to-2.11. Their magmas were derived from an enriched and deep mantle source without significant crustal contamination. These meta-basic volcanic rocks formed in ELIP. Therefore, the Tengtiaohe Zone is not an ophiolite zone and can link to the Song Da Zone in northern Vietnam. 相似文献
10.