中国火山岩油气藏控制因素及分布规律

中国沉积盆地内主要发育石炭—二叠系、侏罗—白垩系和古近—新近系3套火山岩,火山岩大面积分布,烃源岩与火山岩伴生,形成良好的生储盖组合。东部盆地以中酸性岩为主,主要发育原生型火山岩储层;西部盆地以中基性岩为主,主要发育风化壳型储层,火山岩风化壳储层物性好于原生型储层物性,各种岩性、岩相均能形成有效储层。东部盆地主要发育岩性、断层—岩性油气藏;西部盆地主要发育地层型、构造—地层型、构造—岩性—地层复合型油气藏。松辽盆地深层持续沉降型断陷控制天然气区域分布,生烃断槽控制断陷内天然气分布,近邻生烃断槽的断裂构造带是天然气富集区带,优质火山岩储层控制天然气富集;新疆北部石炭系残留生烃凹陷控制油气平面分布,风化壳规模控制油气富集程度和规模,风化壳地层型有效圈闭控制油气成藏,正向构造背景控制油气运聚。指出中国火山岩有利勘探面积36万km2,预测火山岩中总资源量60亿t油当量以上,勘探潜力大。     

碱硅酸反应与碱碳酸盐反应

碱集料反应（AAR）可分为两类,即碱硅酸反应（ASR）与碱碳酸盐反应（ACR）。二者的共同点是与碱发生的化学反应可导致混凝土中集料的体积增大,从而可能使混凝土甚至整个建筑物或构筑物发生膨胀开裂。文章着重从膨胀过程和机理以及岩石的结构特征探讨二者的特性与差异。ASR类型岩石具有碱活性的前提条件是较低的二氧化硅结晶完整度。只有隐晶质、微晶质、玻璃质或发生过应变的二氧化硅才会具有较高的化学活性,导致混凝土破坏。通过系统研究证实,对碱碳酸盐反应,虽然结晶的完整程度以及白云石（CaCO3·MgCO3）分子式中Ca/Mg比也将影响其与碱反应的速率,但起决定作用的是白云石晶体的尺寸及其在岩石中的分布状态和被基质包围的紧密程度。从微观结构得出的这些特征将有助于加深对碱集料反应膨胀机理的认识。文中还介绍了形成活性白云石的地质环境和碱硅酸反应与碱碳酸盐反应的区分方法。     

Gesteine – Entstehung und Eigenschaften

Rocks – Formation and Properties The origin of rocks is very different and closely associated with natural processes such as volcanic eruption, mountain building and erosion. Rocks are classified in three main groups: (a) igneous rocks, (b) sedimentary rocks, (c) metamorphic rocks. Igneous rocks originate from hot magma, sedimentary rocks from erosion of preexisting rocks and metamorphic rocks from change of preexisting rocks under heat and pressure. Depending on the rock origin rocks possess different properties. Properties like interconnection, hardness and abrasion resistance influence the machining of rocks. During the machining of metals which have predominantly homogenous structure chips are generated. The machining of rocks is rather a brittle fracture combined with a grinding process. Knowledge about rock properties like abrasion resistance is necessary to adjust the machining tool for varying rocks.     

我国沉积盆地火山岩油气地质与勘探

我国沉积盆地内发育石炭—二叠系、侏罗—白垩系和古近—新近系3套火山岩,火山岩与有效烃源岩近源组合匹配最有利,远源组合需断层或不整合面沟通,生烃中心控制油气分布;以火山熔岩、火山角砾岩和风化壳岩溶型储层为主;中国东部断陷盆地火山岩油气藏以近源组合为主,沿断陷高部位爆发相火山岩储层发育,斜坡部位喷溢相火山岩大面积分布,主要形成岩性、构造—岩性油气藏;中西部发育两种成藏组合,沿不整合面分布的风化淋滤型大型地层油气藏最有利。     

福建政和上山岗金银矿床地质特征

福建政和上山岗金银矿床位于闽西北隆起带与闽东火山断坳带交接部位,金银矿体主要赋存于石英脉中,围岩为多屑凝灰岩、岩屑晶屑凝灰岩等,矿体与围岩界限清晰。矿区内构造发育,其中北东向断裂构造是最重要的导矿和容矿构造;北西向断裂为成矿后期构造,是主要的切割破坏矿体构造。     

准西海相浅层石炭系火山凝灰岩油气发现的意义

探讨了准噶尔盆地西缘车排子地区实现浅层海相火山凝灰岩勘探突破的意义。排61井在石炭系火山凝灰岩1113.5-1130.0m井段、常规试油获得日产4.6t/d工业油流,50℃脱气原油粘度390mPa·s,首次实现了车排子地区浅层海相火山凝灰岩勘探的突破。车排子地区具有有利的区域构造条件、储集条件、油源条件、油气运移通道、油藏埋深较浅,而且前人积累了发现开发克拉美丽大气田的经验,具有后发优势。由于排61井钻探的火山凝灰岩不属于优质储集层,可以推断,如果找到更好的储集层,找油前景将会多么乐观。而且,排61井常规试油就获得了工业油流,如果实施压裂改造,必然会大幅度提高单井产能,必能极大地增强在该区域勘探的信心。车排子地区石炭系火山岩分布广泛,具有良好的生储盖条件,总体勘探程度仍较低,具备发现大油田的有利条件。落实烃源岩发育区、有利储层发育带、提高单井产能是石炭系勘探的关键。排61井区已部署第二轮多口探井。     

The break-up of continents and the formation of new ocean basins

Rifted continental margins are the product of stretching, thinning and ultimate break-up of a continental plate into smaller fragments, and the rocks lying beneath them store a record of this rifting process. Earth scientists can read this record by careful sampling and with remote geophysical techniques. These experimental studies have been complemented by theoretical analyses of continental extension and associated magmatism. Some rifted margins show evidence for extensive volcanic activity and uplift during rifting; at these margins, the record of the final stages of rifting is removed by erosion and obscured by the thick volcanic cover. Other margins were underwater throughout their formation and showed rather little volcanic activity; here the ongoing deposition of sediment provides a clearer record. During the last decade, vast areas of exhumed mantle rocks have been discovered at such margins between continental and oceanic crust. This observation conflicts with the well-established idea that the mantle melts to produce new crust when it is brought close to the Earth's surface. In contrast to the steeply dipping faults commonly seen in zones of extension within continental interiors, faults with very shallow dips play a key role in the deformation immediately preceding continental break-up. Future progress in the study of continental break-up will depend on studies of pairs of margins which were once joined and on the development of computer models which can handle rigorously the complex transition from distributed continental deformation to sea-floor spreading focused at a mid-ocean ridge.     

Thermophysical Properties of Diorites along with the Prediction of Thermal Conductivity from Porosity and Density Data

The main focus of this paper involves the use of models to predict the thermophysical properties of diorites. For the prediction of thermal conductivity, an existing mixing law and empirical models have been used. Due to the porosity dependence in all the existing models, ASTM (American Society for Testing and Materials) standard methods have been applied to measure the density, porosity, and specific gravity of diorite rocks taken from the Shewa-Shahbaz Garhi volcanic complex near Mardan, Pakistan. The chemical composition of these samples has been analyzed using the X-ray florescence technique. The theoretically calculated values of specific gravity and the density of the specimen based on the chemical composition and porosity are in good agreement with those obtained from experimental measurements at ambient conditions. The thermal conductivity and thermal diffusivity of these rocks have been measured simultaneously using the transient plane source (TPS) technique at room temperature. The effective thermal conductivity calculated from various models is in agreement with the experimental data within 15%. Simple correlations between estimated density and porosity and between the effective thermal conductivity and porosity are also established.     

Pitfalls in ammonia absorption refrigeration

Aqua-ammonia absorption refrigeration (AAR) was invented 131 years ago, but this versatile refrigeration process is increasing in importance today since it consumes mainly low level heat energy. The AAR technique is analyzed and its design and operating problems are discussed with reference to evaporation, absorption and distillation.     

Modeling the cracks opening–closing and possible remedial sawing operation of AAR-affected dams

A significant number of existing concrete dams are at present deteriorated by chemo-mechanical processes known as Alkali-Aggregate Reactions (AAR). This phenomenon is responsible for cracking and expansion of the material which lead to mechanical degradation of the structures operability and safety. Its chemo-mechanical modeling has been already dealt with by considering the influence of temperature, humidity, stiffness reduction and stress in the development of expansion. This modeling has first been developed as valid only for continuous media. In order to widen the field of modeling applicability, this paper describes a novel procedure for modeling displacement discontinuities in AAR-affected concrete structures, mainly to take into account two phenomena: firstly, the modeling of significant isolated cracks opening–closing that result from interactions between expansion and mechanical behavior of the structure; and secondly, the evaluation of the potential efficiency of stress release (e.g. sawing of dams), the procedure of which consists in the creation of slot cutting in the structure for release of excessive compressive stresses. The elaborated model, aimed to possibly combine contact elements and non-linear volume coupled models of durability mechanics related to AAR modeling, was applied to the 3D simulations of a simplified model ideally representing a part of a dam and also to a real gravity dam. Displacements and stresses at the contact elements zone were computed and compared with results of the dam computations without contact elements. The results show that the creation of the slot cutting leads to decrease of the compressive stresses in the structure, which confirms a favorable effect of this stress release technique in order to deal with AAR affected structures.     

Monitoring super-volcanoes: geophysical and geochemical signals at Yellowstone and other large caldera systems

Earth's largest calderas form as the ground collapses during immense volcanic eruptions, when hundreds to thousands of cubic kilometres of magma are explosively withdrawn from the Earth's crust over a period of days to weeks. Continuing long after such great eruptions, the resulting calderas often exhibit pronounced unrest, with frequent earthquakes, alternating uplift and subsidence of the ground, and considerable heat and mass flux. Because many active and extinct calderas show evidence for repetition of large eruptions, such systems demand detailed scientific study and monitoring. Two calderas in North America, Yellowstone (Wyoming) and Long Valley (California), are in areas of youthful tectonic complexity. Scientists strive to understand the signals generated when tectonic, volcanic and hydrothermal (hot ground water) processes intersect. One obstacle to accurate forecasting of large volcanic events is humanity's lack of familiarity with the signals leading up to the largest class of volcanic eruptions. Accordingly, it may be difficult to recognize the difference between smaller and larger eruptions. To prepare ourselves and society, scientists must scrutinize a spectrum of volcanic signals and assess the many factors contributing to unrest and toward diverse modes of eruption.     

Effects of the El Chichon volcanic cloud in the stratosphere on the intensity of light from the sky

This is the second of two papers dealing with the effects of volcanic debris from the eruption of El Chichon on light from the sunlit sky. The polarization of skylight was considered in the first of the two, whereas this one is devoted to skylight intensity. It is shown here that the magnitude of the skylight intensity is modified very significantly from its clear sky value by the volcanic cloud, as is its change with solar depression angle during twilight and its distribution over the sky during the day. Emphasis is on measurements at a wavelength of 0.07 microm. Generally the volcanic cloud produces a diminution of zenith intensity during twilight with a considerable enhancement of intensity over the sky throughout the main part of the day. The solar aureole is not as sharp as it is in normally clear conditions, but the volcanic cloud causes a very diffuse type of aureole which covers a large portion of the sky. The preferential scattering of the longer wavelengths of sunlight, which is made evident by brilliant red and yellow colors in the sunrise period, causes a pronounced change of longwave/shortwave color ratios during twilight from their values in clear atmospheric conditions. The combination of intensity data shown here with polarization data in the previous paper should give a relatively complete picture of the effects of volcanic debris on solar radiation in the atmosphere and be useful in the verification of radiative transfer models of atmospheric turbidity.     

Simulation of a solar driven aqua-ammonia absorption refrigeration system Part 1: mathematical description and system optimization

A theoretical thermodynamic analysis was performed on an aqua-ammonia refrigeration (AAR) cycle coupled to a solar water heating system using CPC-collectors and augmented with auxialiary energy. Thirteen AAR cycles were considered in the search for the maximum coefficient of performance. Also investigated was the exergetic performance of the AAR cycle. The adopted temperature and mass flow rate control strategy on the storage tank-auxiliary heater-AAR generator loop ensured operation of the refrigeration systems at design conditions. Consequently, the ratio between the pumps' electrical power and the designed evaporator heat transfer rate was kept to a minimum.     

Assessment and rehabilitation of AAR-affected structures

The overall thrust of this paper is to show that an integrated material and structural design strategy needs to be adopted to develop techniques that are meaningful and effective for the identification, evaluation and rehabilitation of concrete elements and concrete structures affected and damaged by AAR. It is shown that exposure to environmental and climatic changes is the major factor influencing the rate of expansion and total expansion of concrete in real structures. AAR is also closely and intimately involved with testing and test methodologies so that material and structural rectification requires a global approach involving diagnostic methods, tests to establish the potential of future expansion, selective sealing of cracks and protection from environmental attack, structural evaluation using non-destructive test techniques and structural strengthening.     

Photocatalysis as a potential tertiary treatment of urban wastewater: new photocatalytic materials

Heterogeneous UV-photocatalytic process has been studied as tertiary treatment of real municipal wastewater. Wastewater photocatalytic treatment was carried out using several materials previously developed as photocatalysts: volcanic ashes and nanostructured titania supported over volcanic ashes. Both material activities in particles were compared with Degussa TiO₂ (powder). Photocatalyst amount influence was studied by varying it between 2 and 10 g L^?1. Wastewater decontamination process was evaluated measuring the chemical oxygen demand evolution with phototreatment time in order to choose the best photocatalytic material and its optimal operation concentration. Moreover, the photocatalytic results obtained were compared with those obtained from photolysis and adsorption studies in wastewater using the same operation conditions. In addition, analyses of main wastewater parameters were made in order to evaluate the complete water decontamination process. Possibility of using photocatalysts in particles shows the main advantage of continuous photocatalyst separation from the water effluent once the decontamination process has finished. Good photocatalytic activities were observed, and it allows to conclude that heterogeneous photocatalysis is an effective method for municipal wastewater treatment, achieving water disinfection and phosphates removal.     

Production technology and provenance study of archaeological ceramics from relevant sites in the Alcantara River Valley (North-eastern Sicily,Italy)

In this paper, volcanic-rich ceramic remains from the archaeological sites of Francavilla, Naxos and Taormina (Province of Messina, North-eastern Sicily) were studied by using inclusions as main provenance marker. Technological features, such as temper choice, vitrification degree and firing temperatures, were investigated by polarizing microscopy, X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Information on the production centres was obtained through the identification of the source area of raw materials used as temper. Indeed, petrochemical analysis of the volcanic inclusions within the examined ceramics displayed strong affinities with structures/textures and compositions of the locally outcropping mugearitic products, probably ascribed to the eruptive activity of an eccentric vent of Mt. Etna (Mt. Mojo). A local production for the studied pottery samples has been therefore advanced, assuming that the used volcanic temper was easily available from the alluvial deposits along the Alcantara River stream, which is connected to the lava flow of Mt. Mojo.     

Where is AAR heading after the 10th International Conference?

A brief overview of research on AAR presented at the 10th AARC is given and new areas of research and future needs are highlighted. Some recent experimental data are presented as examples of details that we would need to understand in order to be able to interpret the effects of parameters such as temperature and chemical environment on the nature of the reactions occurring in the concrete, and on the results of tests carried out to determine the expansion behaviour of aggregates or concrete mixtures. Similar examples are needed for other areas and it appears that understanding AAR and its practical management need further research efforts.     

Alkali release from aggregate and the effect on AAR expansion

In this study, two types of alkali-bearing aggregate, nepheline syenite and alaskite are investigated on their effects on AAR expansion using a new accelerate test method. Crushed nepheline syenite and alaskite with size between 0.15 mm and 0.65 mm are immersed in different alkaline solutions and cured at 150°C, the amounts of released alkalis from aggregates into solutions are determined. Results indicate that nepheline syenite and alaskite could increase AAR expansion when low alkali cements are used, but the enhance effect is weaken largely when high alkali cements are used. Nepheline mineral is stable in saturation Ca(OH)₂ solution, but decomposes when alkali is added into the solution and form new product. Na-feldspar and K-feldspar are stable in alkaline solution, only little dissolution might be found in the crystal interface. It is concluded that alkalis release from these alkali-bearing minerals mainly depend on ion change between surface layer of minerals and Ca²⁺ ion in solution.     

节理岩体爆破的研究现状

描述了目前国内外学者对节理岩体爆破的研究进展,分析了常用的一些数学模型,阐述了人们对爆破块度的测定及预报情况以及计算机模型模拟及其应用。节理岩体本身的特性较一般工程材料更复杂、更特殊,因此在爆破作用中,节理对爆破效果的影响有时比岩体本县物理力学性质的影响更显著,所以研究更有理论意义和实际意义。文章提出了节理岩体爆破的研究工作中今后需要解决的一些问题。     

节理岩体爆破的研究现状

描述了目前国内外学者对节理岩体爆破的研究进展，分析了常用的一些数学模型，阐述了人们对爆破块度的测定及预报情况以及计算机模型模拟及其应用。节理岩体本身的特性较一般工程材料更复杂、更特殊，因此在爆破作用中，节理对爆破效果的影响有时比岩体本县物理力学性质的影响更显著，所以研究更有理论意义和实际意义。文章提出了节理岩体爆破的研究工作中今后需要解决的一些问题。