柴达木盆地三湖地区生物气横向运聚成藏研究

本文系统研究了地层水盐度对微生物菌生长发育的制约，矿化度对生物气在地层水中溶解度的影响，泥岩盖层中高矿化度地层水对封盖性能的控制作用。柴达木盆地三湖（台吉乃尔湖，涩聂湖，达布逊湖）地区主要受南缘昆仑山冰雪溶水的补给，地层水从南向北运移，北斜坡第四系地层水的矿化度最高，北斜坡泻水-汇水区高盐度条件下生物菌的活跃程度受到抑制，影响生物气大量生成并从水中游离出来，中央凹陷及其南部低矿化度条件下更适宜生物气的生成，生物气在地层水中的溶解度随矿化度的增高明显降低，南缘低矿化度水中饱含的生物气经地层水从南向北携带，在北斜坡高矿化度条件上大量游离出来，实验测试证明泥岩饱和高矿化度地层水时，其突破压力增加约100倍，封盖性能大大提高，有效地保存了北斜坡游离相生物气，研究显示生物气总体上具有向北斜坡以水溶气方式进行横向运聚的特征，展示了北斜坡气源补给充足，具有满坡含气的巨大勘探潜力。结合生物气本身的发育特征和三湖地区的水文地质条件，提出了生物所首先以水溶气方式发生远距离的横向运移以后再以游离相进行垂向运聚成藏，这一结论对下一步三湖地区生物气勘探具有直接的指导意义。     

流体烃的他地迁移,生物降解及生物成矿：以西班牙拉,弗罗…

原生有机质及沥青的有机地球化学研究结果表明矿区存在微弱的热异常，地层中原生有机质含量极低，沥青是成矿过程中由含矿热液他地带来的迁移型流体烃，流体迁烃在迁移时发生轻烃组分的分馏。在成矿部位，含有硫酸盐，铅锌和流体烃的深湖热液与携带硫酸盐还原细菌的大气降水汇合，流体烃发生生物降解和水洗溶解并引起硫酸盐的生物还原，生成硫化氢，导致铅锌硫化物沉淀，形成矿床。     

流体烃的他地迁移、生物降解及生物成矿——以西班牙拉·弗罗里达铅锌矿床为例

原生有机质及沥青的有机地球化学研究结果表明矿区存在微弱的热异常，地层中原生有机质含量极低，沥青是成矿过程中由含矿热液从他地带来的迁移型流体烃。流体烃在迁移时发生轻烃组分的分馏。在成矿部位，含有硫酸盐、铅锌和流体烃的深源热液（温度６０一］００℃）与携带硫酸盐还原细菌的大气降水汇合，流体烃发生生物降解和水洗溶解并引起硫酸盐的生物还原，生成硫化氢，导致铅锌硫化物沉淀，形成矿床。     

沉积过程对自生黄铁矿硫同位素的约束

自生黄铁矿是海洋沉积物中还原态硫的主要赋存形式,其形成过程与有机质矿化相关,影响全球的C-S-Fe生物地球化学循环。自生黄铁矿硫同位素分馏主要受微生物硫酸盐还原的控制,但近期的研究成果表明局部沉积环境的改变也可以影响黄铁矿硫同位素的组成,特别是在浅海环境。在浅海非稳态沉积环境内,物理再改造和生物扰动作用,导致硫酸盐还原带内生成的硫化物被再氧化,进而影响黄铁矿的硫同位素值。浅海沉积过程容易受到古气候和海平面变化的影响,引起沉积速率的剧烈波动,导致有机质和活性铁输入的不稳定,进而影响成岩系统的开放性和硫酸盐还原速率,最终影响黄铁矿的硫同位素值。另外,沉积速率的改变还影响硫酸盐—甲烷转换带的迁移,造成有机质和甲烷厌氧氧化硫酸盐还原的相互转化,产生不同的硫同位素信号。东海内陆架泥质区为研究沉积过程对自生黄铁矿的形成及其硫同位素组成的约束机制提供了很好的研究材料。该区域有很好的沉积学研究基础,自生黄铁矿丰富、并且个别层位有生物气（甲烷为主）存在,是研究边缘海C-S-Fe循环的理想场所。     

生物气生成的化学动力学模型及其应用——以柴达木盆地为例

针对国内外评价生物气资源量普遍采用的微生物厌氧发酵法中不能反映生气期的不足,本文从化学动力学角度出发,首先建立有机质生成生物气的化学动力学模型并结合实验条件下生物气产率数据,标定了地质样品的化学动力学参数。在此基础上,考虑菌体浓度和温度对动力学参数的影响,将所标定的动力学参数在柴达木盆地进行初步应用,结果表明柴达木盆地生物气生成速率随埋深先增大后减小,速率最大值对应的深度约为600m,与前人(戴金星等,2003)研究结论相近,说明根据实验室产气率数据标定所建立的动力学模型在考虑了菌体浓度和温度对动力学参数影响之后可以用来定量评价生物气生成期。     

生物气研究现状与勘探前景

综合论述了生物气的特征及其研究进展,着重探讨了生物气成因、地球化学特征、勘探研究现状、生物气形成机制和控制因素,并介绍了生物气系统概念和特征,最后叙述了生物气藏的分布和我国生物气藏的远景。生物气是在还原环境的生物化学作用带内有机质为厌氧微生物所分解的最终产物,它以甲烷为主,并含部分二氧化碳及少量氮气和其它微量气体组分,生物甲烷气δ13C1值一般小于-55‰。生物甲烷气的形成途径主要有乙酸发酵和CO2还原2种类型。生物气生成与其所处的沉积环境、古气候、有机质的类型和丰度、水介质性质、地质作用、沉积时间等众多因素密切相关。生物气埋藏浅,分布广泛,一般存在于三角洲、大陆架和部分陆相沉积环境中,储层时代主要为白垩纪、古近纪、新近纪和第四纪。白垩纪的储量最丰富,古近纪、新近纪次之,第四纪生物气藏的规模一般较小。我国生物气勘探研究历史虽然不长,但生物气资源量丰富,具有良好的勘探前景。     

与细菌活动有关的成矿作用——两个欧洲铅锌矿床实例

法国布·玛和西班牙拉·弗矿床分别产于富含干酪根的白云岩和沥青的铁质白云岩中。正构烷、烷基环已烷、藿烷和甾烷等生物标志化合物研究揭示了成矿时发生过细菌活动。细菌在沉积－成岩早期发育于还原水体中，或在成岩期－成岩期后由大气降水自地表带来，其赖以生存的有机质既可以是生物聚合体（布·玛矿床），亦可以是地质聚合体（拉·弗矿床）。这些微生物在１００℃以下的温度条件下生存繁殖，使硫酸盐还原生成硫化氢，导致铅锌硫化物沉淀     

鄂东铅锌矿床成矿中磷酸盐生物和非生物还原作用的有机地球化学研究

矿床产于三叠系大冶群碳酸盐岩中，有机质来自海相浮游生物和微生物。矿层中有机质发生成熟异常，已达过成熟作用早期。这得到镜质体反射率（Ro达4.6%）和矿物包裹体测温（均—温度达210℃）的证实。部分标本中有机质被微生物降解。硫同位素δ34S值大部分为正值，小部分为负值。综合研究表明在鄂东铅锌硫化物矿床的形成过程中，硫酸盐的生物和非生物还原作用，均具有十分重要的成矿意义。     

低演化烃源岩有机质微生物降解的生标组合特征

研究了吐哈盆地低演化烃源岩有机质受到细菌微生物改造后其生物标志物的分布特征。结果表明:低演化有机质在经受细菌微生物作用时不同系列生物标志物的降解敏感性存在“类阶梯式”序列:正构烷烃＞无环类异戊二烯烷烃＞藿烷＞甾烷＞芳香烃。甾烷C29αββ/（ααα+αββ）和芳烃9 MP/ΣMP是良好的细菌微生物作用有机质的敏感参数。同一烃源岩有机质的生物标志物参数出现:OEP2＞OEP1(OEP1可能出现偶碳优势);藿烷C31αβ22S/22(S+R)＞甾烷C29ααα20S/20(S+R);及甾烷C29αββ/(αββ+ααα)＞C29ααα20S/20(S+R)等异常组合特征,可认为该源岩经历过较强烈的微生物作用过程,其降解程度可用每对参数比值的大小来判识,进而可将这些异常生标组合特征作为判识该地区有无微生物成烃（气、油）的依据。研究区源岩被微生物改造后改变了原始有机质的性质,使其生烃活化能大大降低,在低演化阶段即可生烃,从而有利于低熟油、气的生成。     

热泉热液系统金的成矿地球化学研究

通过腾冲热海、硝塘和藏中羊八井、羊应乡等高温热田内金矿化体地质、地球化学、水化学、微生物和有机质的调查及生物功能实验研究,阐述了热泉热液的金矿化作用和成矿效应。金矿化发生在沸腾面以上非平衡条件和溶解金不饱和且不稳定的水热流体中,金主要富集在非晶质到结晶质的硫化物相中。沸泉、汽泉和热泉流体在升流带和地表泉塘中有不同的成矿效应和特征矿化体,反映了多种成矿作用。证实微生物尤其是嗜热硫酸盐还原菌是热液流体氧化还原作用和金硫化物析沉的内在的动力学因素。     

Anaerobic digestion process: technological aspects and recent developments

The technology of anaerobic digestion allows the use of biodegradable waste for energy production by breaking down organic matter through a series of biochemical reactions. Such process generates biogas (productivity of 0.45 Nm³/KgSV), which can be used as energy source in industrial activities or as fuel for automotive vehicles. Anaerobic digestion is an economically viable and environmentally friendly process since it makes possible obtaining clean energy at a low cost and without generating greenhouse gases. Searching for clean energy sources has been the target of scientists worldwide, and this technology has excelled on the basis of efficiency in organic matter conversion into biogas (yield in the range of 0.7–2.0 kWh/m³), considered energy carriers for the future. This paper gives an overview of the technology of anaerobic digestion of food waste, describing the metabolism and microorganisms involved in this process, as well as the operational factors that affect it such as temperature, pH, organic loading, moisture, C/N ratio, and co-digestion. The types of reactors that can be used, the methane production, and the most recent developments in this area are also presented and discussed.     

吐哈盆地西南缘砂岩型铀矿地质地球化学基本特征

文章通过对含矿目的层及其渗透性的分析、与成矿作用有关的常量和微量元素及部分特征性地球化学指标如有机碳含量、全硫含量、三价铁和二价铁比值的分析，以及流体包裹体成分和物理化学参数的测试，配合铀、铅、碳、氧、硫同位素的分析等方法，综合分析研究区内砂岩型铀矿的地质地球化学基本特征，认为：吐哈盆地西南缘砂泥岩互层地层结构完整且延伸稳定，属弱渗透一渗透性地层，对砂岩型铀矿成矿比较有利。据常量和微量元素分析，认为铀成矿存在着明显的地球化学分带性，其中，氧化带以有机碳和全硫(∑s)含量低、Th／u和Fe2O3／FeO及Ra／U比值高为特征；过渡带(成矿带)以Th／U比值低、∑S、Mo、Re含量高为特征；还原带则以明显的低Fe2O3／FeO、Ra／U比值，高有机碳含量为其特征。其他微量元素如Cu、Pb、Zn、Cr、Co、Ni、zr等及稀土元素在成矿过程中并未得到明显富集。经对相关岩石的铀．镭平衡、气液包裹体及相关同位素的研究，认为铀成矿具有多期次、年代新且集中于第三纪的特点；含矿目的层煤成气提供了成矿所需的还原环境；成矿作用铀源主要来自于含矿目的层本身；铀成矿古流体属低温浅成热液且主要来源于大气降水。     

Effects of heavy metals as stress factors on anaerobic digestion processes and biogas production from biomass

Heavy metals affect the biochemical reactions that take place during anaerobic digestion processes of organic matter. In this review, the different effects observed in anaerobic digestion processes and during the production of biomethane and biohydrogen from several substrates contaminated with and/or inheriting heavy metals from the substrates themselves were discussed. It has been found that heavy metals exert important roles in biochemical reactions. Heavy metals like copper, nickel, zinc, cadmium, chromium and lead have been overwhelmingly reported to be inhibitory and under certain conditions toxic in biochemical reactions depending on their concentrations. Heavy metals like iron may also exhibit stimulatory effects, but these effects have been scantily observed. This review also concludes that the severity of heavy metal inhibition depends upon factors like metal concentration in a soluble, ionic form in the solution, type of metal species, and amount and distribution of biomass in the digester or chain of biochemical reactions which constitute the anaerobic digestion process. A majority of studies have demonstrated that the toxic effect of heavy metals like chromium, cadmium and nickel is attributable to a disruption of enzyme function and structure by binding of the metal ions with thiol and other groups on protein molecules or by replacing naturally occurring metals in enzyme prosthetic groups. This review has not found published data on the effects of heavy metals on the hydrolysis stage of anaerobic digestion process chemistry, and hence further studies are required to depict any changes.     

页岩气聚集条件及含气量计算——以四川盆地及其周缘下古生界为例

为了研究页岩气聚集条件及含气量的影响因素、计算方法,根据页岩气聚集机理、聚集特征将页岩气聚集的因素分为内部因素和外部因素。内部因素主要包括页岩有机地球化学参数、矿物组成以及物性参数等,外部因素主要包括深度、温度、压力等。通过对四川盆地及其周缘下寒武统和上奥陶统—下志留统41块黑色页岩的有机地球化学参数、矿物组成、物性参数、深度、温度、压力等因素对页岩含气量影响作用的分析,可知反映内部因素的有机碳含量、总烃含量、石英含量、粘土矿物含量、孔隙度(裂缝)、密度、黄铁矿含量和碳酸盐含量等8个参数对页岩气聚集具有重要影响。通过对"二参数"、"六参数"、"八参数"与含气量的多元线性回归得出计算页岩含气量的计算公式,据此公式计算的含气量与实测值吻合良好,且参数越多对页岩含气量的预测越准确。本文建议在条件允许的情况下,尽可能多地利用各种参数对页岩含气量进行预测,以达到更好的预测效果。在勘探早期,建议采用简单易得到的两个最主要参数——有机碳含量和孔隙度进行页岩含气量的计算。     

Molecular biogeochemistry of sulfate reduction, methanogenesis and the anaerobic oxidation of methane at Gulf of Mexico cold seeps

The anaerobic oxidation of methane in aquatic environments is a globally significant sink for a potent greenhouse gas. Significant gaps remain in our understanding of the anaerobic oxidation of methane because data describing the distribution and abundance of putative anaerobic methanotrophs in relation to rates and patterns of anaerobic oxidation of methane activity are rare. An integrated biogeochemical, molecular ecological and organic geochemical approach was used to elucidate interactions between the anaerobic oxidation of methane, methanogenesis, and sulfate reduction in sediments from two cold seep habitats (one brine site, the other a gas hydrate site) along the continental slope in the Northern Gulf of Mexico. The results indicate decoupling of sulfate reduction from anaerobic oxidation of methane and the contemporaneous occurrence of methane production and consumption at both sites. Phylogenetic and organic geochemical evidence indicate that microbial groups previously suggested to be involved in anaerobic oxidation of methane coupled to sulfate reduction were present and active. The distribution and isotopic composition of lipid biomarkers correlated with microbial distributions, although concrete assignment of microbial function based on biomarker profiles was complicated given the observed overlap of competing microbial processes. Contemporaneous activity of anaerobic oxidation of methane and bicarbonate-based methanogenesis, the distribution of methane-oxidizing microorganisms, and lipid biomarker data suggest that the same microorganisms may be involved in both processes.     

吐哈盆地下侏罗统八道湾组页岩气成藏条件分析

吐哈盆地下侏罗统八道湾组是该盆地重要的煤炭资源产出的层位。该时期内不仅煤层发育,泥/页岩、碳质泥岩以及暗色泥岩等有利于页岩气生成的岩性也大面积发育。八道湾组泥页岩发育,最大厚度达到200m,泥岩的有机碳含量均值达到了1.85%,干酪根类型以Ⅲ型为主,有机质成熟度已经达到了大量生气的阶段,岩石的石英含量较高,有利于后期开发的实施。按照各项条件的约束,圈定托克逊、吐鲁番、七泉湖一带为煤系页岩气远景区。为本区内页岩气的进一步勘探开发提供基础资料和科学依据。     

下扬子丰城-乐平地区二叠系乐平组页岩气潜力综合评价

下扬子区萍乐坳陷丰城-乐平地区发育二叠系乐平组海陆过渡相泥页岩。在深入调研其构造、沉积背景的基础上,综合利用多种实验手段对岩心有机地球化学特征、岩石类型和矿物特征、物性条件、储集空间类型和含气性进行了系统归纳,并进一步探讨了影响其含气性的沉积和构造因素。研究认为：丰城-乐平地区二叠系乐平组泥页岩厚度差异较大且非均质性较强,王潘里段和下老山亚段为好烃源岩,上老山亚段和中老山亚段为中等烃源岩;其有机质类型以Ⅱ₂型为主,东区倾油而西区倾气;成熟度具有"东低西高"的特征;孔隙空间以微孔隙和微裂缝为主,物性整体表现为特低孔低渗。研究区二叠系海陆过渡环境为有利烃源岩的发育提供了基础,适中的埋藏深度保障了页岩气的赋存并可降低开采成本;但东区受推覆带改造使得该区构造复杂,变形强烈,页岩气保存条件差,西部丰城地区则构造稳定,具有较好的页岩气勘探前景。     

东营凹陷下第三系流体-岩石相互作用研究

盆地内地层流体-岩石相互作用导致储层特征和流体性质发生变化,影响油气藏的形成与分布。本文分析了东营凹陷下第三系地层孔隙流体的化学和动力学特征及其分布规律,根据地层中矿物的组成和结构特征对成岩过程中地层古流体的地球化学特征进行了推测。并通过对典型油田泥岩层和砂岩层中矿物组合及其在地层剖面上的变化规律的实例剖析,揭示了东营凹陷下第三系储层中流体-岩石相互作用的基本特点,在此基础上,建立储层中流体-岩石相互作用的地质/地球化学模型。     

Beyond light: Physical, geological, and geochemical parameters as possible submersed aquatic vegetation habitat requirements

When determining the suitability of a certain area as a habitat for submersed aquatic vegetation (SAV), light and parameters that modify light (epiphytes, total suspended solids, chlorophyll concentration, nutrients) are the first factors to be taken into consideration. As a result, in the past 10 years, light has been the major focus of SAV research. Even so, we are still unable to explain why SAV often occurs in one area but is absent just a few meters away. Recent studies have shown that SAV may not occur in areas where light levels are adequate but other parameters like wave energy and sulfide concentrations are excessive. It is time to look beyond light when determining SAV habitat requirements. This paper summarizes the impact that physical (waves, currents, tides, and turbulence), geological (sediment grain size and organic matter), and geochemical (mainly sulfide) parameters may have on SAV habitat suitality. Light remains an integral part of the discussion but the focus shifts from maximum depths of distribution (determined mainly by light) to the range SAV can colonize between the maximum and minimum depths of distribution (determined mainly by physical forces). This paper establishes minimum depths of occurrence resulting from the effects of tides and waves, preferred ranges in particle size, organic content, and sulfide, as well as lilfide, as well as limits on currents and waves as related to the capacity to stay rooted at one extreme and diffusive boundary layer constrains at the other.     

塔里木东部满东1井志留系天然气成因与成藏期初步分析

满东1气藏的发现是塔里木盆地东部地区油气勘探获得新突破的重要标志。本文充分利用目前所获得的大量地质和地球化学资料,从天然气的组份特征、成因类型、成熟度和气源对比等方面对该井天然气的成因进行了分析,认为满东1井天然气属于海相腐泥型天然气,来源于寒武系-下奥陶统海相过成熟烃源岩,烃类气体组成具有油裂解气的特征。海相泥质烃源岩中氨基粘土矿物在过成熟阶段分解并氧化,形成大量的氮气,导致满东1气藏高含氮气。包裹体和埋藏史研究结果表明满东1气藏成藏过程复杂,主要成藏期为燕山喜马拉雅期。