自贡市大安区江姐村卤气环境污染勘查和原因分析

自贡市历史上长期以来的盐卤开采留下了大量的废弃卤(气)井,目前江姐村地区空气中大范围长期H2s气味有感,针对此状况,进行了相关勘查,通过取样分析数据以及数据的空间关系,基本证实了形成卤气污染的根本原因为废弃卤气井筒的连通作用使下部须家河组和雷口坡组地层中的天然气和卤水沿井筒溢出地表。     

自贡市地质学会第二届会员大会在大山铺召开

自贡市地质学会第二届会员大会于1992年7月2日在自贡大山铺地矿部第二地质大队召开。来自川西南矿区、市盐业地质钻井大队、市盐务局、自贡市恐龙馆、四川省盐业学校、自贡矿管办以及二大队等30个单位的从事盐矿开发、油气勘探、制盐化工、水利工程以及科研教育等部门的近250名地学科技工作者参加了会议。四川省地质学会、自贡市科协、自贡市民政局的领导出席了会议并讲了话。乐山、宜宾、沪州等兄弟学会发来了     

南祁连盆地哈拉湖坳陷青徳地2井三叠系天然气水合物储层特征及其意义

哈拉湖地区目前基本属于地质空白区,有关天然气水合物形成及分布的研究较少,尤其针对该地区天然气水合物储层研究与认识较为有限。青徳地2井(QH-2)位于南祁连盆地哈拉湖坳陷西部,为坳陷内首口天然气水合物调查深井,钻遇第四系、新近系-古近系和三叠系。以青徳地2井三叠系主要储集岩层段岩心为研究对象,通过岩石薄片观察以及孔隙度、渗透率、密度、铸体薄片等物性测试,结合测井资料开展哈拉湖坳陷储层特征研究,结果表明: 青德地2井三叠系储层分布较广,厚度巨大,但储集性能整体较差,绝大部分属非常规储集层,且整体裂隙较不发育,较难形成类似木里地区固结岩层中的裂隙型水合物及孔隙型水合物,而该区冻土层下存在厚层第四系松散沉积物及裂隙相对发育的古近系-新近系,可为天然气水合物形成提供良好的储集空间。     

浅谈定远盐矿建井施工技术

水溶法是井矿盐开采的主要方法,建井在井矿盐开采中起着关键作用;根据本矿区的地质条件、钻采方式、井身结构、技术措施等因素,我单位已形成了较合理有效的卤(井)井钻井施工工艺,现介绍卤(盐)井钻井施工中一些关健工艺和施工经验。     

两元混合天然气定量研究新方法

确定端元气混合比例是混源气定量研究的主要内容。以两元混合天然气为例,首先要分析混源成藏的地质条件,以确定可能的气源岩;然后根据源岩生气模拟实验与实测数据,建立端元气与混源气的地球化学模型,确定混源气的混合比例与源岩成熟度;最后将结果用于混源成藏过程分析,提出混源成藏的地球化学机制。鄂尔多斯盆地中部奥陶系风化壳天然气为上古生界煤成气和下古生界油型气混源气。从混源气藏形成的地质条件和地质过程着手,利用天然气中甲、乙烷百分组成和碳同位素组成,建立了混合比例估算模型,并绘制了估算图版。对靖边等气田13个天然气样品进行研究,发现混源气混合比变化很大。除去全为煤成气(陕21井)和全为油型气(陕5井)的两个样品之外,11个样品上古生界煤成气和下古生界油型气比例分布分别为22%～84%和16%～78%。但总体以下古生界油型气为主,平均所占比例63.2%,说明鄂尔多斯盆地中部奥陶系风化壳天然气以下古生界自生油型气为主。     

自贡市大山铺沙溪庙组中沉积间断新发现及其重要意义

自贡市大山铺沙溪庙组中沉积间断新发现及其重要意义易智强（西南石油地质局第二地质大队）近年来，在研究四川盆地形成演化的过程中，分别在不同层位中识别出许多明显或不明显的侵蚀间断面，对推动和深化盆地演化研究进程起到了十分重要的作用。因此，广大地质工作者都十...     

中国天然气地球化学研究新进展及展望

本文系统总结了近十年来中国天然气地球化学最新研究进展,包括天然气生成理论(生物气-低熟气成因、海相有机质和煤系气源岩高演化阶段生气潜力)、大气田成藏过程示踪研究(海相叠合盆地深层、陆相深层砂岩和火成岩大气田)、非烃气体地球化学特征及成因(CO2等H2S)、非常规天然气地球化学特征(致密砂岩气、页岩气和煤层气)、天然气实验新技术和新方法等。这些研究进展丰富了天然气地质学理论,促进了中国大气田的发现。但是随着中国天然气勘探向复杂地质环境区域、深部层系和致密砂岩气等非常规天然气资源发展,地质条件下全过程天然气生排运聚地球化学模型、深部天然气生成和运移及成藏地球化学、致密气等非常规天然气成藏地球化学等是今后天然气地球化学的重要研究方向。     

宁夏固原采卤井施工技术

结合宁夏固原采卤井的地质概况、盐井技术参数及要求、钻探设备、钻井工艺等方面对采卤井施工进行了介绍,重点阐述了钻井液、固井、水平井对接施工等关键工艺技术措施,并列举了施工中出现的粘土侵、含石膏泥岩缩径垮塌、大斜度井段沉砂等突出问题,并就其处理方法进行了分析探讨,总结了采卤井施工经验。     

资中县双河矿区岩盐的发现

自贡市盐业地质钻井大队,在资中县城西南17公里处威远背斜东端的双河矿区黑卤普查工作中,于1978年8月资2井中首次发现了岩盐。继后于1980年又在资3井发现花花盐。但因资2井未直接获取岩盐矿心,故一直未予以报导。笔者通过对已获资料的整理,认为在该区发现的岩盐是肯定存在的,且对岩盐体特征有些认识。现报导如下:     

浅谈卤（盐）井技术割管施工技术

通过卤(盐)井的维修施工,消除各种井内故障,恢复生产能力,使卤(盐)井达到设计开采量,同时也能最大程度利用地下宝贵的资源。技术割管在卤(盐)井可将悬挂在溶腔内的技术管按设计要求割断,并掉入溶腔,从而实现卤(盐)井的第二梯度开采;对对接井而言,则可排除溶腔内堆积的沉淀物对直井的不利影响,实现斜井进水直井出卤开采方式,最大程度地满足正常的卤(盐)开采运行模式。我单位经多年的工程实践,已形成了较合理有效的卤(盐)井维修施工工艺,现介绍卤(盐)井割管维修施工中一些关键工艺和施工经验。     

百色盆地那坤地区那读组淡水灰岩储层裂缝成因分析

以岩心描述为基础,结合声发射实验和碳氧同位素、包裹体成因类型及均一温度分析成果,对那坤地区那读组淡水灰岩储层裂缝特征和裂缝成因进行了深入研究。研究结果表明:那坤地区那读组淡水灰岩储层主要发育有垂直裂缝、高角度裂缝和斜交裂缝;裂缝主要有构造裂缝与非构造裂缝两类,构造裂缝有追踪叠加成岩压裂斜缝发育形成复合裂缝;裂缝部分被方解石完全充填或半充填,部分未被充填而呈开启状;裂缝发育受到3次不同构造应力场作用的影响;构造裂缝对改造和改善储层孔渗性具有重要的贡献。     

天津市古潜山奥陶系岩溶裂隙发育规律研究

奥陶系在天津平原区是具有开发前景的基岩热储,但是在开发过程中发现,该层岩溶裂隙发育极不均匀,富水性相差较大,给施工带来一定的难度,严重阻碍着地热资源的开发进程。为此,对全市近百眼揭露奥陶系地热井的资料进行对比分析,对不同构造单元奥陶系一、二类裂缝发育和原始出水量情况进行统计,总结其岩溶裂隙发育规律。研究结果表明:岩溶裂隙多分布于灰岩较纯的马家沟组,泥质灰岩较发育的亮甲山组和冶里组次之;在埋深小于2 300 m的地区,奥陶系裂隙发育随地层厚度的增大而增大;上覆地层为新近系和中生界的岩溶裂隙发育厚度大于上覆地层为石炭系的;双窑和潘庄凸起岩溶裂隙较发育,富水性较好;张性断裂附近岩溶裂隙最发育。据此可知,岩溶裂隙多分布在张性断裂附近、灰岩较纯的马家沟组,以及埋深较浅、上覆地层为新近系和中生界的凸起区,这些地区富水性较好,可为地热开发提供可靠依据。     

河间构造地裂缝应力场二维剖面模型研究

华北平原是我国地裂缝发育较为密集的地区,河北沧州河间地裂缝具有典型构造影响特征。为分析沧州河间地裂缝发育特征、成因机制,通过求解平面应力问题的有限单元方法反演了沧州河间区域构造应力场,确定了最大主应力场和最大剪应力集中区,从而探索分析构造地裂缝的潜在危险区,建立了地裂缝二维剖面模型,计算分析河间地区区域构造应力场及区域应力集中区与地裂缝的对应关系。研究了二维状态下区域构造应力场的总体特征和规律以及活动断裂对地裂缝的成生、扩展和发育分布的控制关系。分析认为,河间地区地裂缝是由下伏基底延展变形及随之产生的断裂活动提供内动力使应力集中区域发育,具有构造型地裂缝的典型发育特征,是河间地裂缝形成及发展的主要因素。     

渭河盆地安仁镇地裂缝基本特征与成因分析

2016年野外地质调查发现渭河盆地东北侧安仁镇发育48条地裂缝,造成沿线房屋墙体开裂、道路错断和农田变形龟裂等,并严重威胁大西高铁安全运营。通过详细的地质调查和地质测绘发现其均位于地貌分界线两侧并发育在双泉-临猗断裂上盘,地裂缝走向为NE60°~80°,按发育位置可将其划分为5组地裂缝。选取典型地裂缝为研究对象,利用槽探和工程地质钻探揭示了地裂缝的剖面结构特征,发现地裂缝导致浅部土体破裂严重,地裂缝错断两侧地层且位错量随深度增加而增加,表现出同沉积断层的性质。在此基础上,对比西安地裂缝并详细分析了安仁镇地裂缝的成因机理,发现构造断裂、地震活动和表水潜蚀是地裂缝形成的主要因素。安仁镇地裂缝成因机理可概化为:构造控缝、地震启缝和表水扩缝。     

略论矿区的引裂构造

一、引裂构造概念不论成矿物质来源如何,地质构造总是形成矿床的必备条件之一,对于内生和复生矿床来说,特别重要的条件是断裂构造。与成矿有关的断裂,按其规模和控矿特点,大致可以分成三大类:①区域深大断裂,一般与岩浆-成矿域(带)相联系;②地区性大断裂,制约岩石-成矿区(带);③矿区性断裂,控制矿田、矿床和矿体的空间展布。本文提出的引裂断裂构造,属矿区构造。所谓引裂构造,是说断裂的控矿机制在于引生次一级或次多级的容矿裂隙,断裂与裂隙构成矿区的成矿断裂构造系统,视断裂-裂隙的级数多少而可分别称为二级或多级成矿断裂     

Water escape fissures resembling ice-wedge casts in Late Quaternay subaquesous outwash near St. Lazare Québec, Canada

Post-depositional structures in late Quaternary subaqueous outwash near St. Lazare, Québec resemble icewedge casts but are interpreted as water escape fissures. Cryogenic origin is discounted because, in contrast with ice-wedge casts, the fissures have a higher depth to width ratio, do not form an intersecting network, and do not exhibit adjacent upward turning of strata. In addition, their truncation by the sub-littoral unconformitydemonstrates formation before regression of the post-glacial Champlain Sea, under conditions in which ground ice development was highly unlikely. The fissures probably formed in response to elevated pore pressures caused by melting of remnant glacier ice or by liquefaction of deeper units. Excess pore water pressure initiated upward flow of dilute sediment-water mixtures that became concentrated in planar zones (fissures) along which they entrained and removed sediment. Slumping of the fissure walls followed, either during or after water escape. Minor faulting over cavities created by melting ice or water escape along fractures in underlying strata may have controlled the morphology of the fissures.     

Structural Attributes of Travertine-Filled Extensional Fissures in the Pamukkale Plateau,Western Turkey

Numerous active and inactive fissure-ridge travertines are located in the hanging wall of the Pamukkale range-front fault, a large normal fault bounding the northeast side of the Denizli Basin. A typical principal fissure-ridge comprises flanking bedded travertines dipping gently away from a nearly vertical, irregular central fissure, partially filled by vertically banded travertine. More complex ridges bear parasitic fissures and associated ridges on their flanks. Fissures roughly follow the long axes of ridge crests, some of them being divided into angular segments and others anastomosing. The traces of fissures are commonly parallel but some are oblique to one another. Fissures vary in width from a few millimeters to 5 m, and range in length from a few meters to a few kilometers.

The widths of central fissures are at a maximum near the midpoints of ridges, but decrease toward both ends, suggesting that they grew in length over time. Lateral fissure development involved the opening of both new and old cracks, some of which propagated into former process zones at crack tips. Fissures increase in width with depth either gradually or in a series of steps, depending on whether there was a uniform rate of fissure dilation during travertine deposition or episodic dilation during fracture propagation. The characteristic irregular morphology of fractures probably reflects extension-fracture propagation in differential stress fields that were weak as a consequence of location near the earth's surface. The fissures probably express a set of subsidiary extension fractures splaying from the Pamukkale range-front fault into its hanging wall.     

陕西双王金矿床矿化富集规律对成矿构造的指示意义

双王金矿床是秦岭地区大型的危机矿山之一,找矿工作是当务之急,但其成因类型特殊,人们对其成矿构造的演化过程和控矿机制尚存在争议.以该矿床KT5矿体为例,研究了角砾岩体、断裂裂隙和金品位的空间分布关系,并结合趋势面分析,探讨了金矿化富集规律及其对成矿构造的指示意义.矿床地质特征及对矿区内基性岩墙的测年结果表明其成矿时代为印支期.在印支期秦岭造山过程中的NS向主压应力背景下,成矿断裂早期右行斜向剪切作用奠定了角砾岩带的雏形;断裂中期活动引发的地震及伴生液压致裂作用,使矿区内形成了角砾岩主体和断裂裂隙系统,主成矿阶段角砾岩化作用减弱,断裂裂隙持续发育,并作为流体运移和成矿的主要通道和有利部位,使金的矿化富集呈面状展布,断裂裂隙带的产状变化是金沉淀的重要影响因素;晚期构造应力转换为近EW向拉伸,近NS向基性岩墙群侵位并受到成矿流体的改造.      

Travitonics: using travertines in active fault studies

Late Quaternary travertines deposited from hot springs can reveal much about the neotectonic attributes and histories of structures. On the basis of field studies in the Aegean region (Turkey and Greece), the northern Apennines (Italy) and the Basin and Range province (USA) we conclude that the following relationships are of predictive value: (i) travertine deposits are preferentially located along fracture traces, either immediately above extensional fissures or in the hanging walls of normal faults; (ii) the locations of many travertine fissure-ridge deposits coincide with step-over zones (relay ramps) between fault segments; networks of intersecting tensional fissures reflecting the complex strains experienced in such settings are probably responsible for enhancing hydrothermal flow; (iii) the morphology of travertine deposits overlying extensional fissures is controlled by the rheology of the underlying materials; tufa cones (towers, pinnacles) form on former and present lake floors where fissures underlie unconsolidated sediments, whereas fissure-ridges develop where fissures cut bedrocks at the surface; (iv) fissure-ridges comprise outwardly dipping bedded travertine flanking a central tensional fissure filled by vertically banded travertines; fissures can be used to infer local stretching directions; (v) where there are travertines datable by the U-series method it is possible to calculate time-averaged dilation and lateral propagation rates for individual fissures; (vi) most fissures cutting fissure-ridges comprise self-similar angular segments with fractal dimensions in the range 1.00–1.12, the properties of bedded travertine combined with stress perturbations at fissure tips probably being responsible for such similar fractal dimensions being inferred from such a wide range of locations. Fissures gradually increasing in width with depth are products of continuous fracture dilation in contrast to those that form during episodic dilation which display stepped increases of width with depth; (vii) travertine deposited from springs along fault zones accumulate in terraced-mounds sited down slope of the spring line; (viii) many post-depositional fractures cutting travertine deposits are locally oriented at right angles to deposit margins; and (ix) systematic joints in travertines are restricted to those parts of eroded sheet deposits that have been exhumed.     

鄂西渝东区构造裂缝发育特征及力学机制

针对鄂西渝东区隔档式褶皱发育的构造特点,结合区域构造演化史,分别以隔档式褶皱和正弦曲线几何形态的褶皱建立模型,用有限元法模拟了褶皱不同构造部位的应力场分布特征。褶皱外侧为张应力集中区,内侧为压应力集中区,且应力矢量与地层产状平行,二者以中部既无明显挤压、亦无明显拉张的中和面为分界。通过野外露头和岩心观察,总结了鄂西渝东区构造裂缝发育的三种形式:具多层介质的非能干层中发育顺层裂缝;向斜内侧、背斜外侧的能干层中发育高角度剪切缝;背斜外侧、内侧具多层介质的非能干层中发育顺层裂缝与高角度缝共生的网状缝。这种特征与模拟结果呈现较高程度的一致性,可根据应力场模拟成果和裂缝发育地层的能干性进行合理解释。复向斜中的隆起区可作为页岩气勘探的重要目标。