济阳坳陷新生界岩性油气藏特征及油气富集条件

济阳坳陷是一个富含油气的新生代断陷一坳陷盆地,不同区带上岩性油气藏的富集需要同时具备3个基本条件.1）丰富的油源是油气富集的物质条件,济阳坳陷发育多套有效烃源岩,其层系厚度大,分布面积广,资源规模大,与储集砂体之间具有利接触关系.2）优质的砂岩体岩性圈闭是油气富集的聚集条件,应具有圈闭规模大、发育有利的储集相类型和良好储集层的特点.圈闭规模大表现为大规模砂岩体岩性圈闭或数量众多的小型岩性圈闭叠合连片,有利的储集相主要集中在少数3种类型即（扇）三角洲相、浊积扇相和河流相,其中各类储集相的扇中亚相最有利于油气聚集,良好的储集层表现为具有好的砂体类型,并与次生孔隙带形成匹配.3）汇流通道的存在是油气富集的输导条件,充足的油气通过断层汇流通道和孔隙（裂隙）汇流通道运移,在砂岩体圈闭聚集成藏并形成油气富集.因此,济阳坳陷岩性油气藏表现出"主元富集"的特征,即上述的3个基本条件控制了油气在部分次级单元的少数区带发生富集.     

内蒙古二连盆地岩性油气富集因素分析

根据近年来在内蒙古二连盆地有关岩性油藏方面取得了很多勘探成果,通过对4个主力凹陷的岩性油气富集因素进行分析,认为形成岩性油气富集的3大主要因素是:(1)丰富的油源;(2)优质的砂岩体圈闭;(3)存在汇流通道。丰富的油源是油气富集的物质基础,二连盆地发育的2套有效烃源岩层系厚度大、分布面积广、资源规模大,与储集砂体之间具多种接触关系。优质的砂岩体圈闭具有圈闭规模大、发育有利的储集相类型和良好储集层的特点,这些是油气富集的关键因素。圈闭规模大表现为单一大规模砂岩体圈闭或多个小型圈闭叠合连片,扇三角洲、辫状河三角洲和湖底扇是有利的储集相类型,油气富集往往形成于良好的储集层中。此外,存在汇流通道是油气富集的重要因素,充足的油气通过指状砂体侧向汇流通道和断层垂向汇流通道运移,在优质的砂岩体圈闭中聚集成藏。     

惠民凹陷基山砂体成岩作用及对油气圈闭的影响

惠民凹陷基山砂体成岩作用对岩性地层圈闭的形成具有重要的控制作用。通过砂体储层结构和成岩作用分析发现,半径在0．4μm-1．5μm之间的孔喉占累计渗透率贡献值达到90％。分析表明,基山砂体主要储集空间为次生孔隙,主要是由长石等陆源碎屑矿物蚀变而成的自生高岭石晶间微孔,其孔径与压汞分析测试值吻合较好,是与之对应的岩石主要储集空间。压实作用造成的岩石物性致密带和沿砂体边缘形成的碳酸盐胶结层,构成了成藏组合中的区域盖层和局部盖层。即受成岩作用控制,基山砂体层段内致密胶结层和次生孔隙带为油气圈闭提供了有效的储盖组合。这说明成岩作用可以作为相对独立的因素控制油藏的圈闭条件,成岩相研究是连接油藏、圈闭和成岩现象的基本桥梁。     

川东天东地区石炭系天然气富集因素

天东气区是近年来在川东石炭系发现的富矿，储集条件好，产量高，气富集不完全受构造圈闭。经研究发现，气的富集主要受开梁古隆起的控制，它不仅形成了一第列地层－构造复合圈闭，并在该区石炭系沉积相和成岩作用有利于孔洞发育的基础上，促使石炭系储层的有效厚度和孔洞更发育而具有较好的储集条件。     

中国盆地火山岩特性及其与油气成藏作用的联系

在全面总结火山岩的特性、火山岩油气藏的成藏条件、类型以及成藏控制因素的基础上,详细列举了与火山岩油气藏成藏过程密切相关的火山岩的岩相、岩性、储集空间类型及其形成、演化的主要控制因素。火山岩具有良好的储集条件,其储集空间主要为裂缝和孔隙等,储集空间的发育程度主要受岩相、岩性、粒度、构造应力和充填期等因素的制约;丰富的生油层、优越的储集条件、火山岩裂隙主要发育期和油气聚集期相近、良好的盖层以及适当的圈闭条件相匹配,则有利于油气聚集成藏。火山岩型油气藏的勘探已成为油气储量和产量的新增长点。     

岩性圈闭地质风险评价原则与方法探讨

依据对油气勘探理论和圈闭概念的理解和认识,认为在建立岩性圈闭地质模型时,对岩性圈闭的地质风险评价应分3个层次进行,即圈闭的成藏环境、圈闭自身的成藏条件和圈闭可靠性的评价,从而得到圈闭的含油气性系数或圈闭的地质风险系数.在分析圈闭自身的成藏条件时,应对传统的"生、储、盖、运、圈、保"进行分类和归纳,利用圈闭获得油气的能力、圈闭的储集能力、圈闭的后期保存条件"三要素"对岩性圈闭的含油气性进行评价.运用该评价系统对西部新区塔里木、准噶尔盆地中的储备圈闭进行了评价,其评价结果均较合理.     

火成岩油气藏成藏机理探讨

本文以济阳坳陷罗151块火成岩油气藏为例,通过对侵入岩体围岩的生油条件、辉绿岩体储集空间及油气运移与圈闭形成的时空配置关系等方面的研究,综合岩心、地球物理及试油等方面的资料,具体阐述了罗151块火成岩油气藏的特点及成藏模式。研究表明,火成岩作为一种特殊类型的油气储集层,形成具工业价值油气藏须具备一定的石油地质条件：充足的石油来源、有利的生储盖组合、由裂缝—孔隙系统构成的储集空间、有效的圈闭（圈闭形成时间与油气运移时间的相互关系、圈闭位置与油源区的空间关系）及必要的保存条件等;但由于火成岩油气藏储集空间类型复杂、成因多样,其平面及纵向储层非均质性差异极大,开展对不同类型火成岩储集层储集空间成因研究,是解决减小火成岩油气藏勘探风险及合理布置开发井网问题的关键。     

内蒙古商都地区CO2气藏地质条件研究

本文以商都盆地第三系CO2气成藏条件研究为目的，通过对区域构造（断裂、火山活动、岩浆作用）和地层特征及沉积相研究，结合地震勘探成果、CO2碳同位素、氦同位素分析成果，系统探讨了商都盆地CO2气源、运移通道、储集条件、圈闭及盖层条件，并对CO2气成藏模式进行了分析。认为：该区CO2气为幔源成因气，通过包兰哈达－高勿素深断裂运移到第三系储集层中富集成藏。第三系河流或冲积扇沉积的粗碎屑岩广泛分布，而且厚度较大，成岩程度低，具有良好的储集条件。新第三纪晚期的湖泛沉积，形成了巨厚的泥页岩盖层。沉积期后的差异压实作用、断裂、火山及岩浆活动等多因素作用，使这一地区局部构造发育，形成岩性－构造圈闭或构造性圈闭，有利于CO2气成藏。     

准噶尔和吐哈盆地株罗系煤层气储集特征

西北侏罗纪陆相盆地低煤级煤层气藏勘探开发近年来受到越来越多的关注,煤层气成藏机制是该区煤层气勘探开发的重要基础工作,而煤层气储集是煤层气成藏的关键地质过程。研究表明:准噶尔、土哈两个侏罗纪陆相盆地低煤级煤储层具有高孔容、高孔比表面积、高游离气储集潜力和低原位吸附气体能力的特征,深部煤储层储集气量显著高于浅部煤储层;浅部煤储层中基本上为吸附气,深部煤储层中吸附气、游离气、溶解气共存,游离气的重要性随埋深增加而增大;构造高点和构造圈闭对深部煤层气成藏具有重大影响,煤层气与常规气兼探与共采在理论上可行,深部煤层气藏可能较浅部煤层气藏更具开发价值。     

基于层次分析法的楚雄盆地油气地质异常评价

层次分析是一种将难于定量化的复杂问题,逐层分解为一系列可定量化的简单问题,进而进行求解的数学方法。将层次分析法用于油气资源定量评价具有较重要的意义。在楚雄盆地定性石油地质研究的基础上,采用层次分析法,选择生烃条件、储集条件、保存条件、圈闭条件、运移条件、油气微渗漏等专题信息,对楚雄盆地有利油气勘探区带进行了评价,认为楚雄盆地最有利的勘探区是牟定断弯背斜带及黑井凹陷超覆带之间的交际地带;片角凹陷;会基关穹窿背斜带。而有利储集带,长期发育的低势区,良好的圈闭条件是此区成藏最有利的控制因素。     

铁假说和HNLC海区的现场铁加富实验

20世纪90年代,JohnMart in提出的"铁假说（ironhypothesis）"和以此为中心的海洋铁加富实验（ironenrichments）成为海洋科学领域最受瞩目的事件。"铁假说"的主要内容是：铁限制了HNLC海区中浮游生物的生产力,并进而影响了CO₂由海洋上层向深层的输出;如果在HNLC海区加入铁,就可以促进浮游植物的生长,消耗掉过剩的 N、P营养盐,加速C从海洋表层向深层输出,最终降低大气中CO₂含量,缓解温室效应。在赤道太平洋和南大洋进行的现场加富实验证明,加入铁以后,这些海区的浮游植物生物量增加,N、P等营养盐被消耗。但是,这些实验并没有降低大气中CO₂含量。铁假说只被证实了一半。     

广义塑性力学理论

实验表明 ,经典塑性力学难以反映岩土材料的变形机制 ,究其原因在于经典塑性力学作了传统塑性势假设、关联流动法则假设和不考虑应力主轴旋转的假设。 广义塑性力学放弃了这些假设 ,采用了分量理论 ,由固体力学原理直接导出塑性公式 ,它既适用于岩土材料 ,也适用于金属。     

Statistical aspects of Parkfield earthquake sequence and Parkfield prediction experiment

This note discusses three interconnected statistical problems concerning the Parkfield sequence of moderate earthquakes and the Parkfield prediction experiment: (a) Is it possible that the quasi-periodic Parkfield sequence of characteristic earthquakes is no uncommon, specific phenomenon (the research hypothesis), but can be explained by a preferential selection from available earthquake catalogs? To this end we formulate the null hypothesis (earthquakes occur according to the Poisson process in time and their size follows the Gutenberg-Richter relation). We test whether the null hypothesis can be rejected as an explanation for the Parkfield sequence. (b) If the null hypothesis cannot be refuted, what is the probability of magnitude m ≥ 6 earthquake occurrence in the Parkfield region? (c) The direct goal of the Parkfield experiment is the registration of precursory phenomena prior to a m6 earthquake. However, in the absence of the characteristic earthquake, can the experiment resolve which of the two competing hypotheses is true in a reasonable time? Statistical analysis is hindered by an insufficiently rigorous definition of the research model and inadequate or ambiguous data. However, we show that the null hypothesis cannot be decisively rejected. The quasi-periodic pattern of intermediate size earthquakes in the Parkfield area is a statistical event likely to occur by chance if it has been preferentially selected from available earthquake catalogs. The observed magnitude-frequency curves for small and intermediate earthquakes in the Parkfield area agree with the theoretical distribution computed on the basis of a modified Gutenberg-Richter law (gamma distribution), using deformation rates for the San Andreas fault. We show that the size distribution of the Parkfield characteristic earthquakes can also be attributed to selection bias. According to the null hypothesis, the yearly probability of a m ≥ 6 earthquake originating in the Parkfield area is less than 1%, signifying that several more decades of observation may be needed before the expected event occurs. By its design, the Parkfield experiment cannot be expected to yield statistically significant conclusions on the validity of the research hypothesis for many decades.     

Axi-symmetric active earth pressure obtained by the slip line method with a general tangential stress coefficient

The axi-symmetric active earth pressure problem has been investigated by several researchers. Most have suggested that it is reasonable to adopt the Haar & von Karman hypothesis in the slip line method. In this study, a general tangential stress coefficient is used instead of the Haar & von Karman hypothesis in the slip line method, and its effect on the earth pressure is discussed. We find that the hypothesis is reasonable when the soil behind the wall fails completely. Using earth pressures when the soil behind the wall begins to fail is better in practice. The earth pressure is expressed with earth pressure coefficients and the coefficients are presented in figures for practical use.     

Folding in intertidal sediments on the west Lancashire Coast, England

Folded mud layers are observed to be spatially associated with dune bedforms in the runnels of a wide multi-barred foreshore. An hypothesis is presented linking the formation of the folds, by porewater and sediment movements, to the growth of the dune bedforms. The hypothesis is supported by published reports of laboratory experiments by other authors.     

Statistical techniques and their application in palynology

The basic principals of hypothesis testing are reviewed, including the development of the hypothesis, the statistical assumptions made, and the test of the hypothesis. The appropriate experimental design and sampling technique for evaluation of hypotheses posed are discussed. Because the analysis of variance involving the F-test should be used in a wide variety of geological experiments, emphasis is placed on this analysis. Many geological experiments result in the measurement of one or more factors on a continuous scale, whereas others are recorded in a discrete fashion. This necessitates the use of a covariance analysis to evaluate the effect of discrete and continuous factors in the same model. Orthogonal comparisons are discussed as they are used to evaluate specific hypotheses following the general test of hypothesis in the analysis of variance or covariance. All procedures discussed are illustrated using actual palynofloral data.     

多元正态总体假设检验在矿化带识别中的应用

根据北瓦地区岩心样品的地球化学数据处理结果,介绍多元正态总体假设检验方法与对应分析相结合在该区铅锌矿化带识别中的应用。从全体数据的对应分析结果出发,将见矿钻孔的样品得分值经稳健处理后作为铅锌矿化带的已知样本,并以马氏距离为统计量对未见矿钻孔的样品进行识别,在一定信度下作出了该区已知铅锌矿化带在深部存在较有意义延伸的统计推断。     

Geochemical constraints on the origin of the Moon

Hypotheses for the origin of the Moon involve variants on capture, double-planet, and fission processes. Double-planet and fission hypotheses are examined in the light of siderophile trace elements. The siderophile trace elements chosen (W, Re, Mo, P, Ga, Ge) have well understood geochemical behavior such that appropriate metal/silicate partition coefficients are available and their abundances in the lunar and terrestrial mantles 4.4–4.5 × 10⁹ years ago may be reasonably inferred. The fission hypothesis of Ringwood (1979) is not consistent with the behavior of Re, Mo, and P. The hybrid fission hypothesis of Wankeet al. (1983) overcomes many of the deficiencies of ringwood's hypothesis, but is not readily reconcilable with the behavior of Re and Ir. The double-planet hypothesis as most recently advanced by Newsom and Drake (1982, 1983) appears to be consistent with siderophile element behavior in the Moon.     

关于“内在水”补给土壤水的假设与初证

本文提出了关于土壤水产生的新假设——“内在水出渗补给说”,即认为土壤水不仅来源于当地大气降水和地表水的入渗,而且还可能来源于“内在水”的“出渗”;同时指出了土壤水在热动力驱动下,随季节温度变化的特征,并通过分析现有的实测资料,初步验证了提出假设的可信性。在结论与展望部分,论述了如果内在水出渗说成立将会具有的重大理论和实际意义,并提出深化研究的必要性和主要研究内容。     

Fossil wood diversity gradient and Far-East Asia palaeoclimatology during the Late Triassic – Cretaceous interval

Mesozoic fossil floras are distributed over eastern Asia (China, Mongolia, Siberia, Korea and Japan) according to a regular latitudinal pattern. Two floras are usually distinguished, a northern type and a southern type, the distribution of which oscillated during the Mesozoic. In Japan, this regular pattern is disrupted by a sharp inflexion of the boundary between the two floras. Two competing hypotheses have been proposed to explain this disruption. One hypothesis advocates later tectonic motion clouding the original pattern, while the other hypothesis proposes that a warm oceanic current allowed the southern flora to grow much further north in coastal areas. We used fossil wood, a biotic component that has not previously been used, for a palaeobiogeographical study of the region. The observed fossil wood diversity at the generic level does not fit with the hypothesis of a warm oceanic current, unless this hypothesis is modified to include alternating warm northbound and cold southbound oceanic currents. Our results provide new evidence for the palaeoecology of the Mesozoic continental biota in Far-East Asia.