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941.
942.
Faults can act as either conduits or barriers for hydrocarbon migration, because they have complicated anisotropic flow properties owing to their complicated three-dimensional structures. This study focuses on the Zhu I Depression, Pearl River Mouth Basin (PRMB), China. In this area, hydrocarbon migration and accumulation occurred over a relatively short period of time and were contemporaneous with fault activation, so the characteristics of hydrocarbon accumulations can be used to deduce the effect of active faults on hydrocarbon migration and accumulation. This study addresses the effect of fault activity on flow properties during hydrocarbon migration through a quantitative and comparative analysis of fault activity vs hydrocarbon accumulation. The fault slip rate and shale smear factor parameters were used to characterise faulting and elucidate its effect on hydrocarbon migration and accumulation. Active faults are generally excellent vertical conduits with strong fault activation resulting in vertical migration of most hydrocarbons and little preservation; traps near faults with fault slip rates greater than 20 m/Ma rarely contain commercial oil and gas accumulations. Faulting can form shale smear, which, if continuous, can act as a barrier to hydrocarbon migration. An active fault can allow hydrocarbon transport from deeper formations and to be trapped by continuous shale smear in shallower strata. Most of the oil and gas in the Zhu I Depression have accumulated near faults with a moderate fault slip rate (<20 m/Ma) and development of continuous shale smear (SSF<4–6). 相似文献
943.
Quantifying time lag of epikarst-spring hydrograph response to rainfall using correlation and spectral analyses 总被引:1,自引:0,他引:1
Understanding spring-flow characteristics in karst areas is very important for efficient utilization of water resources. The time lag of a spring-hydrograph response to rainfall is related to karst hydrogeological properties such as thickness, porosity and hydraulic conductivity. The length of the time lag can be determined based on results of the time-series analysis. However, some approaches, with different identifying indicators, give different lengths of the time lag. In this study, the flow-discharge series of two hillslope springs located in a karst area of southwest China were used to compute lengths of the time lag. The thickness and porosity of the epikarst-zone fractures on the two hillslopes were estimated based on a ground-penetrating radar investigation and field measurement. Based on comparison of lengths of the time lag computed by auto- and cross-correlation analyses, the identifying indicators of the time lag were classified into three types for measuring short, intermediate and long-term responses of the spring hydrograph to rainfall. The study also reveals that the time lag of spring-hydrograph response to rainfall in the thick epikarst zone is much longer than that in the thin epikarst zone. 相似文献
944.
太原西山煤田赤峪勘查区地层总体为向南南东缓倾的单斜,在此基础上发育有轴向北东的不对称向斜(东社向斜),局部发育短轴背、向斜和一系列与主体向斜轴向大致平行的正断层,并向南西收敛。区内主要含煤地层为石炭系太原组和二叠系山西组,主要可采煤层为2、3、4、8+9号煤层。根据煤岩煤质分析结果,2号煤层为低中灰一中灰、特低硫—低硫煤,3号和4号煤层为低中灰一中灰分、低硫一中硫分煤,8号和8+9号煤层属低中灰、中高硫煤,9号煤层属中灰、中硫煤。总体来看赤峪地区可采煤层为低灰-中高灰,特低硫-中高硫、发热量较高、强一特强粘结性的优质焦煤。全区煤层均为发热量较高、强粘结性的焦煤。 相似文献
945.
946.
Guofeng Zhu Tao Pu Yuanqing He Peiji Shi Tao Zhang Wei Wei Hewen Niu 《Environmental Earth Sciences》2013,70(6):2807-2816
The present study investigated the chemical composition of summer precipitation at different altitudes in Yulong Snow Mountain, hoping to obtain some basic information about the chemical characteristics of precipitation. A couple of precipitation samples at different altitudes in the Yulong Snow Mountain area in southeastern China were collected from July 26 to July 31, 2005 for chemical analyses. Sea-salt tracer analysis showed that Cl? and Na+ had high proportion from marine sources, while the other ions mainly were from non-marine sources. Statistics showed that the cation concentrations ranged from 0.51 to 5.26 mg L?1 and anion concentrations ranged from 0.99 to 4.90 mg L?1. Further analysis showed that terrestrial ions, especially from the proximal terrestrial sources, largely affected the ion concentrations in precipitation. Ion concentrations of precipitation were correlated significantly with local atmospheric circulation at altitude 2,950–4,800 m, and also correlated closely with human activities at altitude 2,400–2,950 m. Limestone, the majority of local rocks, caused high cation concentrations in precipitation, such as Ca2+ and Mg2+. The majority of vapors in the region came from the Indian Ocean whereas parts came from the eastern Pacific. The inorganic ions in precipitation increased significantly in the Yulong Snow Mountain area during this century. Compared with most of the high altitude Mountains in China, the precipitations in the Yulong Snow Mountain area had higher concentrations of inorganic ions and low acidic ion concentrations. The conclusions can provide a basis for study of regional climate characteristics, environment and ecological characteristics of Yulong Snow Mountain area. 相似文献
947.
Multivariate analysis of heavy metal pollution in street dusts of Xianyang city, NW China 总被引:3,自引:2,他引:1
Urban street dust is one of important indicators of the status of urban environmental pollution. There are many studies in capital cities, but little attention has been paid to this kind of study in medium cities, especially in China. The dust samples were collected in the district of traffic crossroads in Xianyang city, Shaanxi Province. Pb, Cd, Cu, Ni, Zn, Cr and Mn concentrations were determined by using atomic absorption spectrometry. The results indicate that street dusts in Xianyang city have elevated metal concentrations as a whole in comparison with Shaanxi Province soil, except for Mn. The content of heavy metals was comparable to those in capital cities. Correlation coefficient analysis, principal component analysis and cluster analysis were used and three main sources were identified; Mn comes mainly from soil sources; Cu, Zn and Ni are mainly derived from industrial sources combined with traffic sources; Pb, Cr and Cd have traffic sources. Heavy metal enrichment factors were calculated, which can reflect human influence degree of street dusts. 相似文献
948.
针对保德区块中低阶煤储层压裂过程中容易出现砂堵影响储层改造效果的问题,根据研究区块的地质条件,结合水力压裂时裂缝在煤层中的扩展规律,分析了保德区块煤层水力压裂出现砂堵的4类主要原因,分别为煤储层裂隙相对发育造成压裂液滤失量增加、压裂沟通高渗透性的顶底板、煤储层本身有效厚度大滤失量增大及多层合压造缝不充分。在此基础上,提出了相应的技术对策,使用清洁压裂液、适当提高并稳定施工排量及优化压裂施工设计,为现场的水力压裂施工和提高煤储层改造效果提供重要指导。 相似文献
949.
咸阳市城区地下水超采问题及对策 总被引:5,自引:0,他引:5
咸阳市是陕西的第三大城市,城市用水严重依赖地下水,地下水起采问题相当严重,已形成了三个区域性地下水降落漏斗.本文通过地下水水位现潮资料,对成阳地下水起采区现状和成因进行了初步分析,并提出解决和缓解这一局面的对策. 相似文献
950.
CSAMT法在四台矿402盘区陷落柱构造探测中的应用 总被引:10,自引:7,他引:10
可控源音频大地电磁法应用于寻找煤田落陷落柱构造,乃是个新课题。通过对大同矿务局四台矿402盘区的野外实际应用,发现了两个陷柱落构造,与实际资料基本吻合。 相似文献