水合物及其在多孔介质中导热性能的研究

气体水合物是一种笼形混合物，它是水分子形成的主体框架包裹其他客体分子形成的一种非化学计量的冰状物质。在海底和大陆的永冻区有大量的天然气水合物，由于天然气水合物富含天然气资源（约2x1016时），并且其稳定性关系到全球气候和海洋地质结构的变化，因而受到广泛的关注。所以在考虑对该资源进行热开采和考察地球温压变化对含水合物层的影响时，有必要掌握水合物的热物性和含水合物层的有效导热系数（ETC）。另一方面，水合物虽然具有明确的晶体结构，但研究表明n型水合物具有玻璃体的导热特性，即其具有低导热系数和导热系数随温度变

纳米流体中HFC134a水合物的生成过程

提出制冷剂气体水合物在纳米流体中快速生成的设想，通过HFC134a气体水合物在纳米铜流体（由0．04％的十二烷基苯磺酸钠（SDBS）水溶液和名义直径为25nm的纳米铜粒子组成）中的生成实验验证了此设想．实验结果表明，与去离子水中HFC134a气体水合物的生成过程相比，纳米铜流体中SDBS是造成HFC134a气体水合物诱导时问明显缩短的主要原因，而纳米铜粒子对诱导时间的影响不大；纳米铜流体中SDBS的乳化作用和纳米铜粒子大比表面积大大促进了HFC134a在水中的溶解；纳米铜粒子的加入明显加强了HFC134a气体水合物生成过程中的传热传质，随着纳米铜粒子数的增加，HFC134a气体水合物生成过程明显缩短．

气体水合物生成特性实验研究

实验研究了添加剂对甲烷气体水合物形成过程的影响。发现微量的表面活性剂降低了甲烷气体水合物在静止反应器中形成的诱导时间，并使水合物快速形成和生长，提高了水合物形成过程中的填充密度。阴离子表面活性剂（十二烷基硫酸钠）对水合物生长的促进作用比非离子表面活性剂（烷基多糖苷）强。液态烃环戊烷降低了水合物形成的诱导时间，但环戊烷不能提高水合物的填充密度。

二氧化碳收集利用与处置技术分析

化石燃料的燃烧是百余年来大气中二氧化碳（CO2）浓度增加的主要原因。CO2的收集和处置则是抑制这一趋势的有效途径。本文通过对现有收集利用和处置技术的分析，认为火电厂是收集CO2的重点考虑对象；CO2用于三次采油及天然气回收在技术上和经济上比较可行；蓄水层储气前景广阔值得研究；深海处置有待进一步探索；CO2用于置换开采天然气水合物也是很有前景的方案。

Study on methane hydration process in a semi-continuous stirred tank reactor

The methane hydration process is investigated in a semi-continuous stirred tank reactor. Liquid temperatures and reaction rates without stirrer are compared with those occurring with stirrer, while at the same time better stirring conditions of the methane hydration process are given by the experiments. Some basic data of fluid mechanics, for example, stirring Reynolds number, Froucle number and stirrer power, are calculated during the methane hydration process, which can be applied to evaluate stirrer capacity and provide some basic data for a scaled up reactor. Based on experiment and calculations in this work, some conclusions are drawn. First, the stirrer has great influence on the methane hydration process. Batch stirring is helpful to improve the mass transfer and heat transfer performances of the methane hydration process. Second, induction time can be shortened effectively by use of the stirrer. Third, in this paper, the appropriate stirring velocity and stirring time were 320 rpm and 30 min, respectively, at 5.0 MPa, for which the storage capacity and reaction time were 159.1 V/V and 370 min, respectively. Under the condition of the on-flow state, the initial stirring Reynolds number of the fluid and the stirring power were 12,150 and 0.54 W, respectively. Fourth, some suggestions, for example, the use of another type of stirrer or some baffles, are proposed to accelerate the methane hydration process. Comparing with literature data, higher storage capacity and hydration rate are achieved in this work. Moreover, some fluid mechanics parameters are calculated, which can provide some references to engineering application.

天然气水合物沉积物力学性质的试验研究

利用研制的天然气水合物沉积物合成及力学性质一体化试验设备,以粉细砂土作为土骨架,分别对冰沉积物以及对四氢呋喃(THF)、二氧化碳(CO_2)和甲烷3种水合物沉积物进行了室内合成和三轴剪切试验,分析和比较了这4种沉积物样品的应力-应变和强度特性,初步探究了冰和不同气体在水合物沉积物强度中所起的作用. 试验结果表明:4种沉积物均表现为塑性破坏;围压越大,水合物沉积物强度越高;在水合物含量相同条件下,不同气体水合物会使水合物沉积物的强度不同

沉积物中导热体周围水合物分解范围研究

沉积物水合物在热源周围的分解范围是水合物热开采以及相关灾害分析的重要基础数据.该文针对平面内边界有恒温热源的水合物热分解范围问题进行了理论分析和四氢呋喃水合物沉积物模型实验,并将两者结果进行了对比.结果表明:沉积物水合物最大分解范围主要取决于热源与环境温度的温差;热源周围水合物热分解最大范围的理论值与实验值接近,误差小于5%

Diversity, abundance and distribution of amoA-encoding archaea in deep-sea methane seep sediments of the Okhotsk Sea

The authors would like to thank Jin Sun, Jian Sun, Liangliang Kong, Nianshuang Wang, Chunhui Wang, Linbao Zhang and Ying Zhang for their assistance in the project. This work was supported by China Ocean Mineral Resources R&D Association grants DYXM-115-02-2-20 and DYXM-115-02-2-6, Hi-Tech Research and Development Program of China grant 2007AA091903, China National Natural Science Foundation grant 40576069, National Basic Research Program of China grant 2009CB219506 and the Fundamental Research Funds for the Central Universities of China grant 09CX05005A. M. G. K. was funded by incentive funds provided by the UofL-EVPR office and the US National Science Foundation (EF-0412129).

Fine-scale vertical distribution of bacteria in the East Pacific deep-sea sediments determined via 16S rRNA gene T-RFLP and clone library analyses

Although the deep-sea sediments harbor diverse and novel bacteria with important ecological and environmental functions, a comprehensive view of their community characteristics is still lacking, considering the vast area and volume of the deep-sea sedimentary environments. Sediment bacteria vertical distribution and community structure were studied of the E272 site in the East Pacific Ocean with the molecular methods of 16S rRNA gene T-RFLP (terminal restriction fragment length polymorphism) and clone library analyses. Layered distribution of the bacterial assemblages was detected by both methods, indicating that the shallow sediments (40 cm in depth) harbored a diverse and distinct bacterial composition with fine-scale spatial heterogeneity. Substantial bacterial diversity was detected and nine major bacterial lineages were obtained, including Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Nitrospirae, Planctomycetes, Proteobacteria, and the candidate divisions OP8 and TM6. Three subdivisions of the Proteobacteria presented in our libraries, including the alpha-, gamma- and delta-Proteobacteria. Most of our sequences have low similarity with known bacterial 16S rRNA genes, indicating that these sequences may represent as-yet-uncultivated novel bacteria. Most of our sequences were related to the GenBank nearest neighboring sequences retrieved from marine sediments, especially from deep-sea methane seep, gas hydrate or mud volcano environments. Several sequences were related to the sequences recovered from the deep-sea hydrothermal vent or basalt glasses-bearing sediments, indicating that our deep-sea sampling site might be influenced to certain degree by the nearby hydrothermal field of the East Pacific Rise at 13A degrees N.

Methane-derived authigenic carbonates from the Ulleung basin sediments, East Sea of Korea

Authigenic carbonates were sampled in methane-enriched piston core sediments collected from gas venting sites on the western continental slope of the Ulleung Basin, East Sea of Korea. Multidisciplinary investigations on these carbonates, including the scanning electronic microscope (SEM) observations and mineralogical-geochemical compositions, were carried out to identify the carbon and oxygen sources and the forming mechanism of these carbonates. The authigenic carbonates from the study area correspond to semi-consolidated, compact concretions or nodules ranging from 2 to 9 cm in size. X-ray diffraction and electron microprobe analyses showed that most of the sampled carbonate concretions were composed of almost purely authigenic high-Mg calcite (10.7-14.3 mol% MgCO3). Characteristically, microbial structures such as filaments and rods, which were probably associated with the authigenic minerals, were abundantly observed within the carbonate matrix. The carbonates were strongly depleted in delta C-13 (-33.85 parts per thousand to -39.53 parts per thousand Peedee Belemnite (PDB)) and were enriched in delta O-18 (5.16-5.60 parts per thousand PDB), indicating that the primary source of carbon is mainly derived from the anaerobic oxidation of methane. Such methane probably originated from the destabilization of the underlying gas hydrates as strongly supporting from the enriched O-18 levels. Furthermore, the strongly depleted delta C-13 values (-60.7 parts per thousand to -61.6 parts per thousand PDB) of the sediment void gases demonstrate that the majority of the gas venting at the Ulleung Basin is microbial methane by CO2 reduction. This study provides another example for the formation mechanism of methane-derived authigenic carbonates associated with gas-hydrate decomposition in gas-seeping pockmark environments. (c) 2009 Elsevier Ltd. All rights reserved.

The characteristics of BSRs and their derived heat flow on the profile 973 in the northeastern South China Sea

Processing of a recently acquired seismic line in the northeastern South China Sea by Project 973 has been conducted to study the character and the distribution of gas hydrate Bottom-Simulating Reflectors (BSRs) in the Hengchun ridge. Analysis of different-type seismic profiles shows that the distribution of BSRs can be revealed to some extents by single-channel profile in this area, but seismic data processing plays an important role to resolve the full distribution of BSRs in this area. BSR' s in the northeastern South China Sea have the typical characteristics of BSRs on worldwide continental margins: they cross sediment bed reflections, they are generally parallel to the seafloor and the associated reflections have strong amplitude and a negative polarity. The characteristics of BSRs in this area are obvious and the BSRs indicate the occurrence of gas hydrate-bearing sediments in the northeastern South China Sea. The depth of the base of the gas-hydrate stability zone was calculated using the phase stability boundary curve of methane hydrate and gas hydrate with mixture gas composition and compared with the observed BSR depth. If a single gradient geothermal curve is used for the calculation, the base of the stability zone for methane hydrate or gas hydrate with a gas mixture composition does not correspond to the depth of the BSRs observed along the whole seismic profile. The geothermal gradient therefore changes significantly along the profile. The geothermal gradient and heat flow were estimated from the BSR data and the calculations show that the geothermal gradient and heat flow decrease from west to east, with the increase of the distance from the trench and the decrease of the distance to the island arc. The calculated 2 heat flow changes from 28 to 64 mW/m(2), which is basically consistent with the measured heat flow in southwestern offshore Taiwan.

鄂霍次克海天然气水合物区与东海内陆架泥质区沉积物古菌多样性研究

为研究鄂霍次克海天然气水合物区沉积物古菌、甲烷厌氧氧化古菌和硫酸盐还原细菌的多样性分布，我们以PCR技术为基础构建mcrA、dsrAB和古菌16S rRNA 基因文库。对所获得的序列进行系统进化和统计学分析发现：鄂霍次克海古菌类群主要为Marine Benthic Group D (MBG-D)、Marine Benthic Group B (MBG-B)、Marine Crenarchaeotic Group I(MG- I)，另外少量古菌16S rRNA基因序列为Anaerobic Methanotrophs 2c（ANME-2c），主要分布在LV39-25H岩心的表层沉积物中。LV39-40H岩心表层的古菌群落结构与其他六个层位古菌群落结构相比有着显著的差异。mcrA基因序列主要为催化甲烷厌氧氧化的古菌ANME-2（c和d簇），在所研究的各个层位的沉积物中均广泛分布。少量的ANME-1（a簇）发现于LV39-40H岩心表层以下的沉积物中。产甲烷古菌数目不多，集中分布在LV39-25H岩心200cm和LV39-40H岩心180cm的沉积物中。dsrAB基因文库分析表明硫酸盐还原细菌种类丰富，表层沉积物中硫酸盐还原细菌多样性最高。在两个岩心所有层位的沉积物中都有一定数量的克隆属于DSS簇，它们可能与ANME共生催化甲烷的厌氧氧化作用。总之，所有数据表明在鄂霍次克海天然气水合物区存在着较活跃的甲烷厌氧氧化作用，揭示了参与甲烷厌氧氧化作用的微生物群落结构和多样性。 为研究东海内陆架闽浙沿岸泥质区不同深度沉积物中古菌群落垂向分布特征，通过古菌16S rRNA 基因文库共得到473个有效克隆50个OTUs (Operational Taxonomic Units)。16S rRNA基因序列系统进化和统计分析发现古菌分别归属于泉古生菌（Crenarchaeota）和广古生菌（Euryarchaeota），其中以Miscellaneous Crenarchaeotic Group（MCG）为主，仅含少量的MBG-B、South African Gold Mine Euryarchaeotic Group(SAGMEG)、 ANME-3、MG- I和MBG-D。该泥质区沉积物可能存在由ANME-3催化的甲烷厌氧氧化作用，同源序列分析表明其古菌群落分布与周边环境有较大联系。UniFrac与沉积物环境因子分析表明该泥质区古菌群落垂向分布与沉积物有机质含量和粒度变化密切相关。 通过对比发现，鄂霍次克海天然气水合物区甲烷厌氧氧化古菌主要为ANME-2和少量的ANME-1，而东海内陆架泥质区甲烷厌氧氧化古菌仅为极少量的ANME-3；鄂霍次克海天然气水合物区广古生菌和泉古生菌数量各占一半，主要为MBG-D、MBG-B、MG-I。东海内陆架泥质区沉积物古菌序列主要为泉古生菌（MCG）。海域类型的不同以及有机碳含量等环境因子的差异可能是这两个海域古菌群落结构差异的主要原因.

南海北部陆缘深水区构造演化及其资源效应

南海北部陆缘深水区（水深>300m）蕴藏着丰富的资源，我国对深水区的地质研究刚刚起步，但相关领域已成为科研热点。深水油气盆地的构造演化是油气勘探中最重要的基础性研究之一，因此针对我国南海北部陆缘深水区开展构造演化及其资源效应的研究具有重要的理论意义和实际意义。 本文利用钻井和地震资料并结合区域地质资料，重点研究了珠江口盆地深水区的结构和构造演化，取得如下创新性成果：1）首次利用半地堑分析方法系统解剖了研究区的结构、各构造单元发育特征，在此基础上指出五个有利油气运聚带；2）采用回剥法并利用最新资料进行校正，得到了研究区更为可靠的构造沉降曲线，重新划分了裂陷期和裂后期的分界，认为32Ma南海海底扩张之后裂陷作用仍在持续，直到23Ma左右才开始大规模裂后热沉降，并进一步解释了裂陷期延迟的形成机制；3）应用非连续拉张模型计算拉张系数的方程计算了研究区的壳幔拉张系数，指出了深水区地幔相对于地壳的优势伸展作用；首次运用平衡剖面技术重建了研究区的构造发育史，计算了各构造期的拉张率和沉积速率，指出研究区新生代整体呈现持续拉张，拉张系数在1.1-1.24之间；4）精细刻画了水合物钻采区的地质构造特征，建立了该区天然气水合物成藏的概念模式；建立了一套根据地震叠加速度计算流体势的方法，为水合物成藏规律的研究提供了新的思路。

鄂霍次克海天然气水合物区柱状沉积物LV39-18H微生物多样性研究

冷泉是指温度接近于海水，而以高于周围水环境浓度的烃类化合物（主要为甲烷）、硫化物或二氧化碳为主要成分，受地质构造或压力梯度作用渗出沉积物表层的流体。对冷泉沉积物中微生物群落的调查，有助于认识该极端环境中某些生理未知微生物类群的功能并理解微生物活动对整个系统的影响。 本文对从鄂霍次克海冷泉区采集获得的沉积物样品按深度划分得到的11个断层中的6个断层进行了总基因组的提取，利用16S rDNA作为分子标记，构建克隆文库并结合总有机碳、总氮、硫等环境因子对该样品中的细菌和古菌群落结构沿沉积物断层的分布情况进行研究，结果显示该沉积物中的细菌和古菌均具有高度多样性且显示出明显的成层分布： 1.细菌群落主要来自10个细菌门，优势门类为绿弯菌、未定门JS1、γ-、δ-变形菌，同时还发现浮霉菌、未定门OP8、放线菌、酸杆菌、拟杆菌、疣微菌的存在。我们还在分布于表层沉积物δ-变形菌类群中发现了占该层群落15%以上的SRB（硫酸盐还原菌）类群，这强烈提示着该沉积物环境中存在着AOM（甲烷厌氧氧化）过程。 2.古菌类群主要划分为DSAG、MBG-D、MCG、MGI、MBG-A和MHVG等类群。其中MBG-D类群沿断层的垂直分布与沉积物中硫含量表现出相似的变化趋势，这提示MBG-D类群可能参与该环境中硫相关的地质化学过程。

东海陆架盆地西南部烟囱构造与油气运聚关系研究

In recent years, chimney structure has been proved one of important indicators and a useful guide to major petroleum fields exploration through their exploration history both at home and abroad. Chimney structure, which has been called "gas chimney" or "seismic chimney", is the special fluid-filled fracture swarm, which results from the boiling of active thermal fluid caused by abruptly decreasing of high pressure and high temperature in sedimentary layers of upper lithosphere. Chimney structure is well developed in continental shelf basin of East China Sea, which indicates the great perspectives of petroleum resources there. However, the chimney structure also complicated the petroleum accumulation. So the study of chimney structure on its formation, its effect on occurrence and distribution of petroleum fields is very important not only on theoretical, but also on its applied research. It is for the first time to make a clear definition of chimney structure in this paper, and the existence and practical meaning of chimney structure are illustrated. Firstly, on the viewpoint of exploration, this will amplify exploration area or field, not only in marine, but also on continent. Secondly, this is very important to step-by-step exploration and development of petroleum fields with overpressure. Thirdly, this will provide reference for the study on complex petroleum system with multi-sources, commingled sources and accumulation, multi-stage accumulations, and multi-suits petroleum system in the overlay basin. Fourthly, when the thermal fluid enters the oceanic shallow layer, it can help form gas hydrate under favorable low-temperature and high-pressure conditions. Meanwhile, the thermal fluid with its particular component and thermal content will affect the physical, chemical and ecological environments, which will help solving the problem of global resources and environment. Beginning from the regional tectonic evolution characteristics, this paper discussed the tectonic evolution history of the Taibei depression, then made an dynamical analysis of the tectonic-sedimentary evolution during the Mesozoic and Cenozoic for the East China Sea basin. A numerical model of the tectonic-thermal evolution of the basin via the Basin-Mod technique was carried out and the subsidence-buried history and thermal history of the Taibei depression were inverse calculated: it had undergone a early rapid rift and sag, then three times of uplift and erosion, and finally depressed and been buried. The Taibei depression contains a huge thick clastic sedimentary rock of marine facies, transitional facies and continental facies on the complex basement of ante-Jurassic. It is a part of the back-arc rifting basins occurred during the Mesozoic and Cenozoic. The author analyzed the diagenesis and thermal fluid evolution of this area via the observation of cathodoluminescence, scanning electron microscope and thin section, taking advantage of the evidences of magma activities, paleo-geothermics and structural movement, the author concluded that there were at least three tectonic-thermal events and three epochs of thermal-fluid activities; and the three epochs of thermal-fluid activities were directly relative to the first two tectonic-thermal events and were controlled by the generation and expulsion of hydrocarbon in the source rock simultaneously. Based on these, this paper established the corresponding model between the tectonic-thermal events and the thermal-fluid evolution of the Taibei Depression, which becomes the base for the study on the chimney structures. According to the analyses of the gas-isotope, LAM spectrum component of fluid inclusion, geneses of CO_2 components and geneses of hydrocarbon gases, the author preliminarily verified four sources of the thermal fluid in the Taibei Depression: ① dehydration of mud shale compaction, ② expulsion of hydrocarbon in the source rock; ③ CO_2 gas hydro-thermal decomposition of carbonatite; ④magma-derived thermal fluid including the mantle magma water and volatile components (such as H_2O, CO_2, H_2S, SO_2, N_2 and He etc.). On the basis of the vitrinite reflectance (Ro), homogenization temperature of fluid inclusion, interval transit time of major well-logging, mud density of the wells, measured pressure data and the results of previous studies, this paper analyzed the characteristics of the geothermal fields and geo-pressure fields for the various parts in this area, and discussed the transversal distribution of fluid pressure. The Taibei depression on the whole underwent a temperature-loss process from hot basin to cold basin; and locally high thermal anomalies occurred on the regional background of moderate thermal structure. The seal was primarily formed during the middle and late Paleocene. The overpressured system was formed during the middle and late Eocene. The formation of overpressured system in Lishui Sag underwent such an evolutionary process as "form-weaken-strengthen-weaken". Namely, it was formed during the middle and late Eocene, then was weakened in the Oligocene, even partly broken, then strengthened after the Miocene, and finally weakened. The existence of the thermal fluid rich in volatile gas is a physical foundation for the boiling of the fluid, and sharply pressure depletion was the major cause for the boiling of the fluid, which suggests that there exists the condition for thermal fluid to boil. According to the results of the photoelastic simulation and similarity physical experiments, the geological condition and the formation mechanism of chimnestructures are summarized: well compartment is the prerequisite for chimney formation; the boiling of active thermal fluid is the original physical condition for chimney formation; The local place with low stress by tension fault is easy for chimney formation; The way that thermal fluid migrates is one of the important factors which control the types of chimney structures. Based on where the thermal fluid come from and geometrical characteristics of the chimney structures, this paper classified the genetic types of chimney structures, and concluded that there existed three types and six subtypes chimney structures: organic chimney structures generated by the hydrocarbon-bearing thermal fluid in middle-shallow layers, inorganic and commingling-genetic chimney structures generated by thermal fluid in middle-deep layers. According to the seismic profiles interpretations, well logging response analysis and mineralogical and petrological characteristics in the study area, the author summarized the comprehensive identification marks for chimney structures. Especially the horizon velocity analysis method that is established in this paper and takes advantage of interval velocity anomaly is a semi-quantitative and reliable method of chimney structure s identification. It was pointed out in this paper that the occurrence of the chimney structures in the Taibei depression made the mechanism of accumulation complicated. The author provided proof of episodic accumulation of hydrocarbon in this area: The organic component in the boiling inclusion is the trail of petroleum migration, showing the causality between the boiling of thermal fluid and the chimney structures, meanwhile showing the paroxysmal accumulation is an important petroleum accumulation model. Based on the evolutionary characteristics of various types of chimney structures, this paper discussed their relationships with the migration-accumulation of petroleum respectively. At the same time, the author summarized the accumulating-dynamical models associated with chimney structures. The author analyzed such accumulation mechanisms as the facies state, direction, power of petroleum migration, the conditions of trap, the accumulation, leakage and reservation of petroleum, and the distribution rule of petroleum. The author also provides explanation for such practical problems the existence of a lot of mantle-derived CO_2, and its heterogeneous distribution on plane. By study on and recognition for chimney structure, the existence and distribution of much mantle-derived CO_2 found in this area are explained. Caused by tectonic thermal activities, the deep magma with much CO_2-bearing thermal fluid migrate upward along deep fault and chimney structures, which makes two wells within relatively short distance different gas composition, such as in well LF-1 and well LS36-1-1. Meanwhile, the author predicted the distribution of petroleum accumulation belt in middle-shallow layer for this area, pointed out the three favorable exploration areas in future, and provided the scientific and deciding references for future study on the commingling-genetic accumulation of petroleum in middle-deep layer and the new energy-gas hydrate.