对煤层气井施工技术的认识

根据施工煤层气井的成功实践,介绍了有关煤层气井的钻井,固井工程及煤层改造等技术措施。     

Contamination of Tris(4-Chlorophenyl) Methane and Tris(4-Chlorophenyl) Methanol in Marine Mammals from Russia and Japan: Body Distribution, Bioaccumulation and Contamination Status

Four seal species (Phoca caspica, Phoca sibirica, Phoca hispida and Phoca largha) and one whale (Orcinus orca) from Russia and Japan were examined to determine the body distribution, bioaccumulation and contamination status of tris(4-chlorophenyl) methane (TCPMe) and tris(4-chlorophenyl) methanol (TCPMOH). Lipid normalized concentrations of TCPMe and TCPMOH were comparable in various organs and tissues, implying that their body distribution is followed to the lipid-dependent accumulation, similar to that for other organochlorines. The highest body burden of these compounds was found in the blubber. Bioaccumulation potential of TCPMe and TCPMOH was high and comparable to PCBs and DDTs. Relatively higher concentrations of TCPMe and TCPMOH were observed in Caspian seal than in other seal species examined. TCPMOH concentration in killer whale was the highest of the marine mammals examined. Another peak detected had similar mass spectrum to TCPMOH, however, at a different retention time, suggesting the presence of an isomer of TCPMOH.     

Sand veins and MISS from the Mesoproterozoic black shale (ca. 1.7 Ga) in North China: Implication for methane degassing from microbial mats

The Mesoproterozoic Chuanlinggou Formation (ca. 1.7 Ga) consists mainly of dark-gray to black shales that are widespread in the North China Platform. Abundant centimeter-scale sand veins are present within the shale layers of this unit, particularly in the middle part. Sand veins display ptygmatic shapes, perpendicular or with a high angle to bedding planes. They penetrate the black shale layers but are often terminated by thin, lenticular sandstone beds, forming small-scale ‘tepee-like’ structures. On bedding planes, sand veins are expressed as small ridges with 1–3 mm positive relief. Lack of polygonal shapes and their occurrence in thinly laminated, relatively deep-water shales preclude an origin from sand-filled desiccation cracks. Instead, their close association with microbially induced sedimentary structures (MISS) such as micro-wrinkles and gas blisters, putative bacterial fossils (possibly coccoidal cyanobacteria) and framboidal pyrites, suggests that they were formed by degassing of methane from microbial mat decay. Methane gas disrupted overlying sedimentary layers, creating fractures open to seawater. Fine-grained quartz sands, which were transported into the depositional environment by strong winds, filled the fractures. Sand-filled fractures were shortened and folded during burial compaction, forming ptygmatic shapes. The presence of dispersed dolomite and siderite in these sand veins suggests authigenic carbonate precipitation from anaerobic oxidation of methane (AOM). Sand veins are intensely distributed within the Chuanlinggou Formation and are spatially widespread in the North China Platform. If their methane origin is confirmed, they may have important implications for the Mesoproterozoic paleoclimate. With anoxic oceans and low seawater sulfate concentration during the Mesoproterozoic, methane release from microbial mat decay and/or microbial methanogenesis during shallow burial may have been proportionally higher than that of the modern marine environments, with resultant increase in the relative importance of methane in maintaining the Mesoproterozoic greenhouse climate.     

地球物理技术在天然气水合物预测中的应用

Based on the sensitivity of geophysical response to gas hydrates contained in sediments, we studied the prediction of gas hydrates with seismic techniques, including seismic attributes analysis, AVO, inverted velocity field construction for dipping formations, and pseudo-well constrained impedance inversion. We used an optimal integration of geophysical techniques results in a set of reliable and effective workflows to predict gas hydrates. The results show that the integrated analysis of the combination of reflectivity amplitude, instantaneous phase, interval velocity, relative impedance, absolute impedance, and AVO intercept is a valid combination of techniques for identifying the BSR （Bottom Simulated Reflector） from the lower boundary of the gas hydrates. Integration of seismic sections, relative and absolute impedance sections, and interval velocity sections can improve the validity of gas hydrates determination. The combination of instantaneous frequency, energy half attenuation time, interval velocity, AVO intercept, AVO product, and AVO fluid factor accurately locates the escaped gas beneath the BSR. With these conclusions, the combined techniques have been used to successfully predict the gas hydrates in the Dongsha Sea area.     

Mud volcanoes of Italy

The locations and information about the sizes of 61 mud volcanoes on the Italian mainland and Sicily, plus an area of mud diapirism in the Italian Adriatic Sea, are presented. Data about the emission products are also provided. The majority of these mud volcanoes are found where thick sedimentary sequences occur within a zone of tectonic compression associated with local plate tectonic activity: the movement of the Adriatic microplate between the converging African and Eurasian plates. The principal gas emitted by these mud volcanoes is methane, which probably originates from deep within the sediments. Other mud volcanoes, associated with igneous volcanism, produce mainly carbon dioxide. The mud diapirs in the Adriatic Sea are thought to form as a result of the mobilization of shallow gassy sediments. It has been shown that radon emissions from mud volcanoes are indicators of forthcoming earthquake events. Copyright © 2004 John Wiley & Sons, Ltd.     

煤层气储层评价的地球物理测井技术

摘 要 基于国内外煤层气地球物理测井技术的发展现状‚综合分析了煤层气储层测井数据 采集技术以及煤层气储层地球物理测井评价技术;讨论了当前煤层气储层评价的地球物理测 井技术所存在的若干问题以及今后值得注意的几个研究发展方向。     

中国深水海域油气及相关资源勘探开发进展及关键技术

深水油气及相关资源的开发是我国解决能源紧缺问题的关键,我国南海深水海域蕴藏着丰富的油气资源,天然气水合物资源赋存也有着良好的前景.本文探讨了深水油气及相关资源开发勘探技术的进展和技术发展方向.     

煤层气开发井网优化设计--以新集矿区为例

以新集矿区为例,系统地研究了煤层气开发井网设计的具体内容及工作程序。根据对新集矿区煤储层地质条件分析,确定了煤层气开发的目标煤层以及布井间距设计原则;通过煤储层数值模拟的产能预测,确定了煤层气开发的井网布置样式;在产能预测的基础上,结合经济分析,优化了煤层气开发的布井间距,进而提出了新集矿区首期煤层气开发布井方案,并进行了产能预测。指出新集矿区煤层气开发应采用地面垂直井、采动区煤层气开发以及井下瓦斯抽放等多种开发方式综合并举的形式。      

无烟煤对甲烷等温吸附解吸特性实验研究

研究空气干燥基无烟煤对甲烷(CH4)的等温吸附/解吸特性,发现其对甲烷的解吸残余率达56%。为了对其进行深入探讨,特设计了原煤样的炭化和活化实验,扩大了原料的比表面积,进而在等温条件下研究了两个改性样品对甲烷的吸附/解吸特性。对比发现,比表面积的增大能显著增加样品对甲烷的吸附总量,但对解吸残余率没有明显的影响。考虑到影响甲烷吸附/解吸的因素,又在等温条件下对主控因素——水分作了平行实验,结果显示,水分对活化样解吸残余率有明显影响。     

功率声波影响煤层甲烷储运的初步探讨

分析了功率声波对煤岩介质孔隙率和渗透率的影响规律及作用机理。结果表明,功率声波能够增加煤的孔隙体积,提高甲烷在煤层中的渗透率;功率声波对煤岩等介质的主要作用机理有机械作用、激波作用、定向作用、热效应、空化作用,使煤岩层产生微裂缝,改变煤岩的孔隙结构,降低甲烷气体的粘度,从而为煤层甲烷开发提供了一种新的思路。