青海木里三露天冻土天然气水合物成藏模式研究

摘要：祁连山地区天然气水合物分布较为复杂,急需对该区天然气水合物成藏控制因素与成藏模式进行深入研究。本次重点对青海木里三露天天然气水合物系 列钻井揭示的地质资料及各种样品分析测试结果进行综合分析,结果显示：该区天然气水合物气源以油型热解成因气为主,少部分在浅部混有部分微生物成因气及煤成气,这些油型热解成因 气源主要由下部或更深部上三叠统或二叠系提供;当气源岩生成烃类气体后运移至浅部直接或间接由断裂连同泥岩、油页岩等封堵形成浅部气体聚集;浅部气体聚集体局部加入微生物成因气 或煤成气,经过不晚于中更新世早期形成的岛状永久冻土作用,在天然气水合物稳定带内与水结合形成天然气水合物,当它们处在天然气水合物稳定带之外便在更浅部以异常高压气层或游离( 吸附)气存在。由于气源类型与供应条件、运移与聚集条件、天然气水合物稳定带范围的不同,它们之间的匹配关系在不同位置具有很大的差异性,从而影响该区天然气水合物在横向平面上和 纵向剖面上分布与产出的不均性。     

川西前陆盆地流体的跨层流动和天然气爆发式成藏

川西前陆盆地是我国西部典型的前陆盆地,也是我国重要的致密砂岩含气区。盆地上三叠统须家河组二段和四段等渗透层中的流体跨过须家河组三段、五段等不渗透层流入侏罗系自流井组、千佛岩组、沙溪庙组、遂宁组和蓬莱镇组等渗透层,即发生了流体的跨层流动。流体的跨层流动一方面使侏罗系砂岩发生了受酸性水控制的次生溶蚀作用,从而改善了侏罗系的储集条件;另一方面为侏罗系形成天然气藏提供了气源条件。盆地天然气成藏具有烟囱效应、早聚晚藏和异常高压等特征。深盆气是天然气早期聚集在川西前陆盆地上三叠统(主要是须二段和须四段)的基本形式,是后期天然气成藏的基础,本文称之为气库区。天然气藏形成是由地壳隆升作用致使早期聚集的气库区决口,引起流体跨层流动,天然气以速度快、规模大和范围窄的形式运移和聚集,本文称之为爆发式成藏。爆发式成藏形成了上三叠统晚期裂缝重组气藏和侏罗系气藏(并非都是次生气藏)两类气藏。早期天然气聚集和定位地区的确定和评价是今后川西前陆盆地天然气勘探的重点和难点。     

曲靖盆地生物气成藏条件及主控因素分析

曲靖盆地新近系茨营组第三段的晚期生物气藏是新近系沉积之后,喜山运动时期各种成藏条件有效的时空配置的结果.在讨论曲靖盆地构造和沉积演化的基础上,综合分析了生物气源、储集层和盖层、圈闭形成以及天然气输导等成藏条件,阐述了生物气晚期聚集成藏条件的时空匹配关系.指出自第四纪以来,生物气源岩持续高效的产气作用是生物气成藏的物质保障,气藏的形成是生物气连续的补充大于逸散动态平衡的产物;背斜构造、砂岩上倾尖灭和砂岩透镜体圈闭是该区主要的圈闭类型;断裂和不整合面是沟通生物气源岩到圈闭的垂向和侧向输导通道,茨营组的连通砂岩体是生物气近距离运移的输导层.蔡家冲组大套湖相暗色泥岩的生物产气效率、断裂的垂向输导能力和圈闭的保存条件及其在时空上的动态配置是生物气晚期成藏的主控因素.     

川西坳陷中段雷口坡组烃源岩评价及气源分析

在对川西坳陷中段雷口坡组烃源岩评价基础上,结合雷口坡组天然气地球化学特征与成藏地质条件分析,探讨了该区不同构造带雷口坡组天然气的气源及差异。烃源岩分析表明:该区雷口坡组烃源岩有机质类型为Ⅱ型,R_o大于2%,但有机质丰度偏低,w(TOC)平均值普遍低于0.3%,普遍未达到有效烃源岩,能为雷口坡组提供的气源非常有限。天然气组分分析显示:新场构造带雷口坡组天然气更富烃类组分,不含或含微量H_2S,而龙门山前构造带雷口坡组天然气更富非烃组分,天然气中H_2S体积分数为3.50%～9.97%,平均值为4.91%,属高含H_2S气藏。受雷口坡组烃源岩生烃有限与雷口坡组多套膏盐层封堵的影响,新场构造带雷口坡组天然气主要来自上覆须家河组烃源岩。龙门山前构造带雷口坡组气藏得益于沟通下伏海相层系的断裂与下伏发育的多套优质烃源岩,下伏海相层系为该区雷口坡组气藏提供了主要的气源。两构造带气源的差异导致了天然气组分特征的显著差异。     

川东石炭系大气田成藏条件分析

川东地区是四川盆地稳定地块中的相对构造活动带，区内发育10排高陡构造带，90年代以来高陡构造带石炭系成组气田勘探获得巨大突破。本文着重讨论了石炭系气藏的成藏条件，指出形成石炭系大气田的各项有利条件，即具丰富气源的志留系、二叠系存在异常高压提供足够的动力促使天然气向区域孔洞型储集层石炭系常压层运移，高陡构造带成串分布的高点是形成成组气田的有利圈闭，石炭系在上覆阳新统高压封闭体系的严密保护下聚集成藏。     

大庆长垣以东地区深层天然气成藏的控制因素及成藏模式

通过长垣以东地区深层天然气分布特征研究,提出了深层天然气成藏的 4种控制因素,即气源条件、盖层条件、断裂和不整合面,并对它们在气藏形成中所起作用进行了深入分析。在此基础上,提出了该区深层天然气成藏的4种模式。即天然气沿不整合面短距离运移基岩风化壳成藏模式,天然气沿裂缝运移源岩区内火山岩成藏模式,天然气沿不整合面或砂体和断层长距离运移古隆起之上各种类型圈闭成藏模式,天然气沿砂体侧向运移地层超覆圈闭成藏模式。最后指出了该区深层有利钻探靶区。     

无机成因二氧化碳气的类型分布和成藏控制条件

从无机成因天然气成藏主控条件－气源断裂体系构造变形场的类型出发,综合分析了无机成因二氧化碳气藏的成因类型,分布规律和成藏控制条件等。结合实例对气源断裂体系结构作了剖析,指出二氧化碳气藏研究中值得重视的几个方面。     

惠民凹陷南坡天然气藏形成条件及勘探方向

从气源岩、储层、圈闭等方面分析了惠民南坡的天然气成藏条件,认为该区烃源岩条件良好,有古近纪的暗色泥岩和石炭-二叠纪煤系地层作为气源岩,同时该区深大断裂发育,岩浆活动强烈,还具有充足的非烃气源;地层发育全,沉积体系多,发育多种类型的储集层,形成6套储盖组合,具备天然气聚集成藏的良好地质条件.研究表明,曲堤地垒和济阳地堑东部的古生界圈闭是深层气勘探的有利方向,非烃气的主要勘探方向是王判镇潜山带的新近纪地层构造圈闭和浅层"亮点"岩性圈闭.     

印缅俯冲增生楔气烟囱分带性及油气成藏规律

印缅俯冲增生楔位于印度板块与欧亚板块俯冲前缘,是深水油气勘探的重要地带。重新审视深水油气勘探潜力、认识增生楔地区油气成藏模式和机理是当前研究热点。印缅俯冲带增生楔提供了一个良好实例和研究契机,它不仅是一个斜向俯冲增生楔,而且是一个气烟囱发育的增生楔。本文基于高精度地震资料,应用地震波组和频谱扫描、地震属性检测以及基于多层感知器的非线性神经网络技术,识别出该区气烟囱具有分带性,且在增生楔斜坡和海沟盆地气烟囱发育。气烟囱总体表现出向海渐新、期次递减的特征,即增生楔斜坡以全新世和中新世两期发育的断层型气烟囱为主,纵向上横跨渐新统至更新统;海沟盆地以全新世发育的背斜型气烟囱为主,纵向上横跨中新统至全新统。气烟囱发育的动力来源为渐新统和中新统烃源岩持续生烃形成的超压,幕式构造活动产生气源通道,古近系和新近系中的泥页岩等提供封盖条件。气烟囱与油气成藏关系密切,具有振幅、频率、相位等地震异常并伴有亮点、平点等地震反射的相关伴生构造是油气运聚的有利目标。结合气烟囱的气源特征,本文提出混源断层型、生物气源断层-背斜型、生物气源背斜型等三种气烟囱成藏模式,指出海沟盆地气烟囱地震异常体具有较好的浅层天然气勘探前景,下覆烃源岩内幕构造、岩性圈闭是另一个有利的油气勘探领域。     

无机成因二氧化碳气的类型分布和成藏控制条件

从无机成因天然气成藏主控条件———气源断裂体系构造变形场的类型（收缩、伸展、走滑和旋转等）出发,综合分析了无机成因二氧化碳气藏的成因类型、分布规律和成藏控制条件等。结合实例对气源断裂体系结构作了剖析,指出二氧化碳气藏研究中值得重视的几个方面。     

Unity of the national and the international in the socio-cultural development of the peoples of the USSR

International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen.     

Deviation of the major axis of the inertia ellipsoid of the Moon from the direction toward the Earth

It is known from observations that the center of mass of the Moon does not coincide with the geometric center of its figure, and the line connecting these two centers is not aligned with the direction toward the center of the Earth, instead deviating toward the Southeast. This stationary deviation of the axis of the inertia ellipsoid of the Moon to the South of the direction toward the Earth is analyzed. A system of five linear differential equations describing the physical libration of the Moon in latitude is considered, and these equations are derived using a new vector method taking into account perturbations from the Earth and partly from the Sun. The characteristic equation of this system is obtained, and all five oscillation frequencies are found. Special attention is paid to the fifth (zero) frequency, for which the solution of the latitude libration equations are stationary and represents a previously unknown additional motion of the rotational axis of theMoon in a cone with a small opening angle. In contrast to the astronomical precession of the Earth, the rotation of the angular-velocity vector is in the positive direction (counter-clockwise), with the period T ₃ = 27.32 days. On this basis, this phenomenon has been named “quasi-precession.” This quasi-precession leads to a stationary inclination of the major axis of the inertia ellipsoid of theMoon to the South (for an observer on Earth), making it possible to explain one component of the observed deviation of the center of mass of the Moon from the direction toward the Earth. The opening angle of the quasiprecession cone is approximately 0.834″.     

Global repeating events in the history of the Earth and the motion of the Sun in the Galaxy

Chronological analyses of correlations between certain global repeating events (mass extinctions of marine organisms, meteorite impacts, and flashes in the frequency of geomagnetic reversals) during the Phanerozoic Eon and the motion of the solar system in the Galaxy are presented for five rotationally symmetrical models for the regular Galactic gravitational field. Thirteen of sixteen mass-extinction events can be described by a repetition interval of 183±3 million years. This is in agreement with the anomalistic period (interval between two subsequent passages of the Sun through the apocenter of its Galactic orbit) in the model of Allen and Martos. The positions of the minima and maxima in Gaussian functions approximating the frequency distribution for geomagnetic reversals also agree with the times of passage of the Sun through the apocenter and pericenter, respectively, of its Galactic orbit in this model. The maximum in the distribution of the deviations of the dates of mass extinctions from the nearest dates of impacts of large, crater-forming bodies is close to zero, providing evidence that many such events are correlated. As a rule, extinctions follow impact events. The impacts of large bodies have occurred most often when the solar system passes through the Galactic plane, while mass extinctions occur more often at some distance from the Galactic plane (about 40 pc). As a rule, intervals of increases in the frequency of geomagnetic reversals coincide with dates of impacts of large bodies. At the same time, these intervals do not show a clear correlation with the dates of mass extinctions. The intensity of mass extinctions, like the energy released by impacts, is consistently higher in periods when the Sun is moving from the apocenter toward the pericenter of its orbit, than when it is moving from the pericenter toward the apocenter. Thus, there is evidence for a variety of relationships between repeating global events in the Phanerozoic and the motion of the Sun in the Galaxy. Long-period variations in the frequency of geomagnetic reversals are correlated with the orbital motion of the Sun, and increases in the frequency of geomagnetic reversals are correlated with impacts. Mass extinctions are correlated with the impacts of large bodies, whose motions may have been perturbed by clouds of interstellar material concentrated toward the Galactic plane and by the shock front associated with the Perseus spiral arm, through which the solar system passes. The velocity of the Sun relative to the spiral pattern is estimated.     

从榴辉岩与围岩的关系论苏鲁榴辉岩的形成与折返

位于华北和扬子两板块碰撞带中的苏鲁榴辉岩形成的温压条件不但是超高压，而且是高温。榴辉岩的PTt轨迹表明其为陆-陆磁撞俯冲带的产物。榴辉岩的区域性围岩花岗质片麻岩为新元古代同碰撞期花岗岩，榴辉岩及其他直接围岩皆呈包体存在于其中，并见新元古代花岗岩呈脉状侵入榴辉岩包体中。区域性围岩新元古代花岗岩的锆石中发现有柯石英、绿辉石等包裹体，表明新元古代花岗岩的组成物质也经受过超高压变质作用，且榴辉岩与围岩新元古代花岗岩的锆石U-Pb体系同位素年龄基本相同。但新元古代花岗岩所记录的变质作用和变形作用期次（或阶段）却少于榴辉岩。椐上述可得如下推断：超高压榴辉岩与新元古代花岗岩岩浆是同时在碰撞带底部（俯冲板块前部）形成的；榴辉岩的第一折返阶段是由新元古代花岗岩岩浆携带上升的，其第二折返阶段是和新元古代花岗岩一起由逆冲及区域性隆起而上升，遭受剥蚀。     

某高速公路下伏煤矿采空区稳定性分析

在论述某高速公路下伏砦脖煤矿采空区地质、采矿和工程地质特征的基础上, 进行了稳定性数值模拟分析, 定性与定量地分析与评价了该煤矿采空区的地表变形特征及稳定性。研究结果表明: 该煤矿采空区的变形尚未完成, 对拟建的高速公路将产生很大的危害, 必须采取相应的工程治理措施。      

摩擦桩基桩土间极限摩阻力取值问题探讨

通过对广珠东线高速公路横沥大桥的试桩及土体的工程地质条件分析,总结出影响摩擦桩基桩土间极限摩阻力取值的一般问题以及解决问题的方法和措施。     

On the consistency of proposed models for the Pyrenees with the structure of the eastern parts of the belt

The structure of the eastern Pyrenees consists mainly of south-directed thrusts involving basement and cover rocks. An antiformal stack developed by the piling up of basement thrust sheets which outcrop in the Axial zone. These structures account for a thin-skinned thrust model rather than a vertical fault model in which the Axial zone would be essentially autochthonous, and the North-Pyrenean fault the axial plane of a fan thrust system. New data from the Eastern Pyrenees and the thin-skinned model suggest that(1) the structure east of the Pedraforca nappe is similar to that of the Central Pyrenees; (2) the cover rocks of the South-Pyrenean units and of the Axial zone-after restoration—built up a northwards-thickening prism consistent with the existence of a unique Pyrenean sedimentary basin during Mesozoic time; (3) the Axial zone is only a complex antiformal stack developed as a part of South-Pyrenean system related to the Paleogene thrusting-tectonics. The Axial zone palaeogeographic area had no special meaning during Mesozoic time.     

Paleomagnetic implications on the evolution of the tethys belt from the atlantic ocean to the pamirs since the triassic

We first re-examined the apparent polar wander curves for stable Eurasia and Africa since the Triassic. These curves were then combined together with curves of North and South America according to the kinematics of the Atlantic ocean and a synthetic polar wander curve was given. Then, most of the paleomagnetic results from the Tethys mobile belt, from the Atlantic to the Pamirs, were analysed.Several groups of plates, microplates and blocks can be seen. First, relatively stable regions like Maghreb and Sicily, which have not moved much. Then we have a group formed by Iberia, Sardinia, Italy and, to a lesser extent, Corsica and the Western and Central Alps. For these blocks, movements are anticlockwise rotations chiefly driven by the anticlockwise rotation of Africa, but they are sometimes stronger.To the east, a major change takes place. The north of the Aegean Sea and the Ionian zone are clockwise rotated and these rotations are recent: Oligocene-Miocene for the first part, Pliocene to the present for the second part.A major problem arises in Turkey, Caucasus and Iran. Paleomagnetic results indicate a position far to the south of Eurasia, and, at the same time, geological evidence is in favour of a position close to Eurasia. We discuss these discrepancies.