康山“沥青脉”的成因

通过对康山固体可燃脉体产状、脉石矿物性质、构造发展史的综合分析，认为民因很可能是下寒武统荷塘组中的的软沥青和有机质，在加里东运动期间，由于区域应力体系的变化而爆炸运移形成的。康山脉石矿物是沥青和有机质，不是煤和无机物。沥青的源岩为下武统荷组富有机质的黑色泥岩、硅质泥岩、硅质岩。康山脉中的固体沥青和有机质，当初挤入时应呈塑性流动状态，康山沥青系由石油经热演化而成。     

矿床讲座

第十二講 外生礦床(五) 石油和天然气石油和天然气的一般特性石油是可燃有机礦物之一,但它和其他可燃有机矿物(煤和油頁岩)又是有着区别的,煤和油頁岩是固体的,而石油是粘稠的油狀物質。石油的顏色是多种多样的,从白色,淺黄色,綠褐色,褐色至黑色的都有,我國老君庙油田所產的石油就是黑色的。     

湖南碳沥青煤成因的探讨

近年来,湘西、湘中和湘南部分县的早古生代地层中,陆续发现了一种充填于断层裂隙中的固体可燃有机岩矿床-碳沥青煤(暂定名)矿床。据不完全统计,已有15处41条矿脉(详见表1),早在百多年前就已开采,是一种较好的民用和化工燃料,其位置和分布情况见图1。      

奥陶系烃源岩有机显微组分特征及意义

鄂尔多斯盆地中部气田奥陶系碳酸盐岩储层中既有煤型气又有腐泥型气。煤型气的来源为上古生界煤系源岩已无争议，但对腐泥型气的来源则存在着源自石炭系和奥陶系自生自储两种不同观点。研究了奥陶系碳酸盐岩中的有机显微组成特征，从有机岩石学角度将其细分为三个显微组分组、六种显微组分，其中的碳沥青组对于碳酸盐岩生烃潜力的评价及认识天然气来源具有指示意义。奥陶系岩石中沥青的成因与赋存状况的分析表明，奥陶系储层中的碳沥青主要为液态烃热演化的产物，奥陶系碳酸盐岩具有生烃潜力。同位素特征分析亦表明上、下古生界储层中天然气的同位素组成存在较大差异。认为腐泥型天然气来自奥陶系碳酸盐岩本身。     

康山“古油藏”讨论之三——康山“沥青脉”的成因

通过对康山固体可燃脉体产状、脉石矿物性质、构造发展史的综合分析,认为其成因很可能是下寒武统荷塘组中的软沥青和有机质,在加里东运动期间,由于区域应力体系的变化而爆炸运移形成的。康山脉石矿物是沥青和有机质,不是煤和无机物。沥青的源岩为下寒武统荷塘组富有机质的黑色泥岩、硅质泥岩、硅质岩。康山脉中的固体沥青和有机质,当初挤入时应呈塑性流动状态,康山沥青系由石油经热演化而成。     

鄂尔多斯盆地奥陶系烃源岩有机显微组分特征及意义

鄂尔多斯盆地中部气田奥陶系碳酸盐岩储层中既有煤型气又有腐泥型气。煤型气的来源为上古生界煤系源岩已无争议,但对腐泥型气的来源则存在着源自石炭系和奥陶系自生自储两种不同观点。研究了奥陶系碳酸盐岩中的有机显微组成特征,从有机岩石学角度将其细分为三个显微组分组、六种显微组分,其中的碳沥青组对于碳酸盐岩生烃潜力的评价及认识天然气来源具有指示意义。奥陶系岩石中沥青的成因与赋存状况的分析表明,奥陶系储层中的碳沥青主要为液态烃热演化的产物,奥陶系碳酸盐岩具有生烃潜力。同位素特征分析亦表明上、下古生界储层中天然气的同位素组成存在较大差异。认为腐泥型天然气来自奥陶系碳酸盐岩本身。     

塔里木盆地深层烃源岩可溶有机组分的碳同位素组成特征

塔里木盆地深层烃源岩主要是指埋深大于4000 m的寒武—奥陶系海相碳酸盐岩和三叠—侏罗系陆相泥岩、碳质泥岩和煤。研究表明,塔里木盆地深层烃源岩可溶有机组分的碳同位素组成具有母质继承效应,寒武—奥陶系海相腐泥型烃源岩可溶有机组分的碳同位素组成一般小于-28‰,而三叠—侏罗系陆相腐殖型烃源岩可溶有机组分的碳同位素组成一般大于-28‰。对于高演化的寒武—奥陶系海相深层烃源岩而言,在热力作用下,其可溶有机组分的碳同位素组成普遍发生强烈逆转,并出现饱和烃>芳烃>非烃>沥青质的完全反序分布现象,显示出深层环境下高演化烃源岩可溶有机组分的碳同位素组成特征。      

甘肃侏罗纪植物化石Ginkgo huttonii角质层地球化学特征

对甘肃民和盆地侏罗纪植物化石Ginkgo huttonii(Sternb．)Heer的角质层与现生银杏Ginkgo biloba的角质层进行了地球化学特征对比分析,结果表明植物化石角质层有机物特征符合石油形成中沥青的演化特点。通过有机物组分含量分析,它们相当于中国中、新生代油源岩有机质类型中的腐泥型一腐殖腐泥型。对烃组分三角图进行投点,落入Ⅱ型干酪根范围内。通过有机质中的一些指标分析,发现Ginkgo huttonii的角质层处于低成熟阶段,与煤中显微组分角质体的成烃模式基本一致。另外,角质层的可溶有机质分布特征表明,植物化石角质层对陆相高蜡原油的形成有一定的作用,证明高等植物对蜡质有贡献。当前研究及古植物学资料表明,银杏是一种有利于煤成油的植物。     

利用Q型聚类分析研究鄂尔多斯盆地多种能源矿产间的关系

为揭示鄂尔多斯盆地多种能源矿产间的关系,根据盆地石油、油气伴生水以及煤、煤层夹矸、铀矿及围岩样品的氯仿沥青中57种元素的分析结果,进行了Q型聚类分析。结果表明：侏罗系下统延安组石油、侏罗系中统直罗组石油与三叠系延长组石油有相近的成因特征;三叠系延长组石油沥青、三叠系延长组含油砂岩沥青与侏罗系中统直罗组石油沥青具有类似的成因特征;神木侏罗系下统延安组煤沥青、东胜侏罗系中统直罗组煤沥青、铜川陈家山侏罗系下统延安组煤层石油以及铜川陈家山侏罗系下统延安组煤沥青成因特征相近;铜川陈家山侏罗系下统延安组煤层石油沥青可能与准格尔黑岱沟石炭二叠系煤沥青具有成因上的联系;侏罗系下统延安组石油沥青与放射性铀矿的形成具有密切关系;天然气的物质来源复杂,且与石油和煤的进一步演化有一定关系。鄂尔多斯盆地多种能源矿产成因较复杂、相互问关系密切,且具有多源性成藏（矿）特征。     

烃源岩残留沥青中正构烷烃分子的碳同位素研究

对不同类型烃源岩残留沥青中ｎC₁₅正构烷烃分子碳同位素特征的研究表明，古生界海相碳酸盐生油岩和中生界淡水湖相泥质生油岩的ｎC₁₅正构烷烃分子呈富12C的碳同位素组成特征；沼泽相腐殖煤的正构烷烃分子呈富C₁₅的特征。煤系暗色泥岩的正构烷烃分子碳同位素组成介于两者之间。沉积环境和有机母质性质是制约烃源岩正构烷烃分子碳同位素特征的主要因素。ｎC₁₅正构烷烃分子系列碳同位素特征不仅是一个良好的油－岩对比和原油成因判识指标，而且还可用于煤成油的进一步划分对比。     

矿物在油气形成过程中的作用

模拟实验结果表明,矿物组成对煤岩样品的模拟实验结果具有很大的影响,不同的矿物以及同一种矿物在不同的有机质热演化阶段,对有机质形成石油和天然气的过程均具有非常明显的影响:高岭土矿物在高温热演化阶段对有机质形成气态烃的过程具有一定的催化能力;碳酸钙（CaCO3）在中—低热演化阶段能抑制气态物质的形成,而在较高的热演化阶段则对煤生成气态物质的过程具有一定的催化作用;四氧化三铁（Fe3O4）在主要的模拟实验阶段对煤生成气态物质的过程均具有一定的催化作用;硫化亚铁（FeS）在低温热演化阶段对天然气的形成具有一定的抑制作用,而在高温热演化阶段则对天然气的形成具有较明显的催化作用;元素硫（S）在不同的热演化阶段对天然气的形成过程均具有非常明显的催化作用。矿物介质不仅对气态产物的产率有比较明显的影响,而且对液态产物的产率也有较明显的影响。模拟实验结果表明:高岭土和四氧化三铁（Fe3O4）在中、低温模拟实验阶段对“氯仿沥青A”的形成具有较明显的催化作用;硫化亚铁（FeS）在整个模拟实验的全过程中对“氯仿沥青A”的形成均具有明显的催化作用;碳酸钙（CaCO3）矿物对“氯仿沥青A”的形成具有明显的抑制作用;元素硫（S）对“氯仿沥青A”的形成具有非常明显的催化作用。     

Solid bitumens: an assessment of their characteristics, genesis, and role in geological processes

Familiar since antiquity, and subject in contemporary times to various characterization schemes, the exact nature of solid bitumen is not yet fully known. Bitumens have ‘random polymer-like’ molecular structures, are mobile as highly viscous fluids or were once fluids but have since turned into solids. Solid bitumens consist mainly of large moieties, of polyclyclic aromatic hydrocarbons, occasionally with finely admixed, fine-grained cryptocrystalline graphite. Solid bitumens are distinguished from kerogen, which is the syngenetic and generally finely dispersed particulate organic matter in sedimentary rock that virtually does not migrate following its deposition. Occurrences of solid bitumens are relevant to petroleum exploration as well as the search for, and evaluation of, a variety of metallic mineral deposits. Genesis of bitumen is in many cases linked to the thermal and hydrothermal history of organic matter in sedimentary rock. Apparently bitumen, or more specifically organic acids generated along with bitumen during diagenesis, may alter porosity of reservoir rocks or otherwise prepare the ground for ore deposition. Bitumen is also relatively sensitive to alteration processes, some of which, such as oxidative weathering, water leaching, biodegradation (contact) metamorphism and ionizing radiation may likewise affect its nature. Elemental composition of bitumen commonly reflects the nature of mineral deposits. Is is possible that in petroleum exploration, trace metal abundances of bitumen may eventually allow prediction of crude oil types and volumes anticipated from a given source rock? Beside transition elements, notably Ni and V, highly anomalous concentrations of U, Pt and Au occur in some solid bitumens. During the generation of petroleum from kerogen, the trend in δ¹³C is toward lighter values. The opposite seems to occur when liquid petroleum is subjected to thermal cracking (and /or related processes) yielding solid bitumen enriched in ¹³C, and isotopically light methane. In fact, except for deasphalting and possibly some irradiation processes, the result of thermal cracking, oxidation, water leaching, inspissation (drying) and bacterial degradation of crude oil is that lower molecular weight hydrocarbons are removed leaving bitumen residues enriched in aromatic hydrocarbons, heteroatomic compounds (NSO) and ¹³C. Such phenomena are relevant to bitumen paragenesis in petroleum reservoir rocks, to certain Phanerozoic occurrences of multiple generations of bitumens, and to bitumens in mineral deposits.     

Petrology and genesis of Karelian shungite—high rank coal

Shungites are highly carbonaceous, highly metamorphosed rocks associated with several stratigraphic levels of the Lower Proterozoic in Karelia. Being a complex material, shungite is very important also as oldest accumulations of concentrated organic matter. The nature of shungite is still unclear despite its more than a century-long study by Russian and western scientists.A chemical coal-petrographic study of shungite has been conducted using a specially designed technique: the etching of polished surfaces. It is found that the shungite bed (near Shunga village) is a coal seam with a typical set of megascopic features rather than an accumulation of bitumen. This bed consists not only of sapropelic but of humic organic matter as well.Unlike other biogenic structures from Precambrian coal, such as the Huron Series, Michigan Lake, the structures established in shungite near Shunga village have a more complex plant composition. Organic matter from various types of shungite-bearing rocks show different petrographic and chemical properties. Thus, organic matter of sapropelic nature from silicate rocks with traces of stromatolite texture, differs from the coal matter composing the Shunga bed. Shungites are the most metamorphosed coals among all those known at present and they are assigned here to metaanthracite rank. The results obtained show a new insight into the biogenic remains composing an ancient coal bed, and in terms of the present stratigraphic scale allow the beginning of coal accumulation to be placed in the Proterozoic, although the possibility of a non-Precambrian age cannot be ruled out.     

Mapping of prospectivity and estimation of number of undiscovered prospects for lode gold,southwestern Ashanti Belt,Ghana

In the southwestern part of the Ashanti Belt, the results of fractal and Fry analyses of the spatial pattern of 51 known mines/prospects of (mostly lode) gold deposits and the results of analysis of their spatial associations with faults and fault intersections suggest different predominant structural controls on lode gold mineralisation at local and district scales. Intersections of NNE- and NW-trending faults were likely predominantly involved in local-scale structural controls on lode gold mineralisation, whilst NNE-trending faults were likely predominantly involved in district-scale structural controls on lode gold mineralisation. The results of the spatial analyses facilitate the conceptualisation and selection of spatial evidence layers for lode gold prospectivity mapping in the study area. The applications of the derived map of lode gold prospectivity and a map of radial density of spatially coherent lode gold mines/prospects results in a one-level prediction of 37 undiscovered lode gold prospects. The applications of quantified radial density fractal dimensions of the spatial pattern of spatially coherent lode gold mines/prospects result in an estimate of 40 undiscovered lode gold prospects. The study concludes finally that analysis of the spatial pattern of discovered mineral deposits is the key to a strong link between mineral prospectivity mapping and assessment of undiscovered mineral deposits.     

塔里木盆地和田河气田碳酸盐岩储层的多期次多来源油气聚集特征

高成熟度演化地区的海相碳酸盐岩储层易受到油气演化的影响 ,油气的聚集在储层中都留下了踪迹 ,既有对储层储集性能的改善有利的一面 ,也有对储层形成伤害的一面。对和田河气田的碳酸盐岩储层薄片观察、凝析油气的地球化学分析和储层沥青分析表明 ,主要有 3期油气运移 ,分别为 :晚加里东期—早海西期、晚海西期和喜山期。前两期都是寒武系来源的油气 ,均被生物降解或散失 ,喜山期是天然气的关键聚集时期。第一期以油相运聚的油气被降解 ,形成的沥青对储层造成了伤害 ,第二期以气相运移的油气多散失 ,仅在储层中留下凝析油 ,第三期油相运移的石炭系来源的油受到后期转移上来的寒武系干气的气侵 ,产生沥青质沉淀 ,使得寒武系凝析油被封堵 ,储层产出的凝析油的地球化学特征更接近石炭系源岩。     

Characterization of solid bitumens originating from thermal chemical alteration and thermochemical sulfate reduction

Solid bitumen can arise from several reservoir processes acting on migrated petroleum. Insoluble solid organic residues can form by oxidative processes associated with thermochemical sulfate reduction (TSR) as well as by thermal chemical alteration (TCA) of petroleum. TCA may follow non-thermal processes, such as biodegradation and asphaltene precipitation, that produce viscous fluids enriched in polar compounds that are then altered into solid bitumens. It is difficult to distinguish solid bitumen formed by TCA from TSR since both processes occur under relatively high temperatures. The focus of the present work is to characterize solid bitumen samples associated with TSR- or TCA-processes using a combination of solid-state X-ray Photoelectron Spectroscopy (XPS), Sulfur X-ray Absorption Near Edge Structure Spectroscopy (S-XANES), and ¹³C NMR. Naturally occurring solid bitumens from three locations, Nisku Formation, Brazeau River area (TSR-related); La Barge Field, Madison Formation (TSR-related); and, the Alaskan North Slope, Brooks Range (TCA-related), are compared to solid bitumens generated in laboratory simulations of TSR and TCA.The chemical nature of solid bitumens with respect to organic nitrogen and sulfur can be understood in terms of (1) the nature of hydrocarbon precursor molecules, (2) the mode of sulfur incorporation, and (3) their concentration during thermal stress. TSR-solid bitumen is highly aromatic, sulfur-rich, and nitrogen-poor. These heteroatom distributions are attributed to the ability of TSR to incorporate copious amounts of inorganic sulfur (S/C atomic ratio >0.035) into aromatic structures and to initial low levels of nitrogen in the unaltered petroleum. In contrast, TCA-solid bitumen is derived from polar materials that are initially rich in sulfur and nitrogen. Aromaticity and nitrogen increase as thermal stress cleaves aliphatic moieties and condensation reactions take place. TCA-bitumens from the Brooks Range have <75% aromatic carbon. TCA-bitumens exposed to greater thermal stress can have a higher aromaticity, like that observed in TSR-bitumens. Organic sulfur in TCA-organic solids remains relatively constant with increasing maturation (S/C atomic ratio <0.035) due to offsetting preservation and H₂S elimination reactions. Although S-XANES and ¹³C NMR provide information needed to understand changes in structure and reactivity that occur in the formation of petroleum solids, in some cases XPS analysis is sufficient to determine whether a solid bitumen is formed by TCA or TSR.     

鄂尔多斯盆地能源矿产氯仿沥青Sm-Nd同位素研究

对鄂尔多斯盆地石油、煤、含铀砂岩及其围岩的氯仿沥青进行了Sm-Nd同位素研究。结果表明,盆地流体(包括深部流体)活动具有多期性,且后期的流体活动对铀矿床的形成具有重要作用;赋存于同一套地层中的含铀砂岩沥青、煤沥青及石油沥青,虽然均具有富集地幔特征,但并非同期活动的产物;东胜矿区侏罗系直罗组煤沥青和盆地西南部陈家山矿区侏罗系延安组的煤沥青,源区时代上存在较大差异,伴生沥青并非全部由煤的热演化形成,可能还存在外来流体的加入,且东胜直罗组煤的伴生沥青较延安组煤的伴生沥青来源深度更大;盆地内马岭油田的直罗组石油沥青、陈家山延安组煤层石油沥青及其煤沥青在源区特征上具有内在联系。     

徐州大屯腐泥煤的煤岩煤质和微量元素特征

运用电感耦合等离子质谱（ICP-MS）、冷蒸汽原子吸收光谱（CV-AAS）、显微镜光度计和煤化学等方法,对江苏徐州大屯矿区张双楼12-1号钻孔腐泥煤（太原组17号煤层）和龙固煤矿腐植煤（太原组21号煤层）的煤岩煤质和微量元素特征进行研究。结果显示,徐州大屯矿区腐泥煤中藻类体含量很高,是典型的藻煤,其挥发份产率和氢含量是腐植煤的1.5倍;腐泥煤的Sr/Ba为1.43,腐植煤为0.48,揭示该腐泥煤是在比较开阔的海水中形成的;腐泥煤和腐植煤中的不相容元素在原始地幔标准化曲线上具有一致的Pb显著富集、Ti显著亏损的分布特征,其稀土元素丰度球粒陨石标准化曲线形态相似,均显示轻稀土富集、重稀土相对亏损的特征;腐泥煤中Ce和Eu元素未发生价态变化,腐植煤中Eu显示负异常。