On the origin of saline fluids in the KTB (continental deep drilling project of Germany)

Highly saline fluids were encountered during the German Continental Deep Drilling Project (KTB) from depths ranging between 2 and 3 km to about 9 km. The most reliable data were obtained from samples extracted during a long-term pumping test in the 4000-m deep KTB pilot hole. Some 460 m³ CaNaCl brines with about 68 g l⁻¹ total dissolved solids (TDS) and some 270 m³ associated gases, mainly N₂ and CH₄ were pumped to the surface from the main fracture system situated near the bottom of the pilot hole. Geochemical and isotopic data support the hydraulic tests which suggest the presence of an open and large fluid reservoir at depth. The pumped fluids from this main fracture system were released from a deep reservoir situated at more than 5500 m depth which is hydraulically connected with the 9101 m deep KTB main hole, drilled some 250 m to the northeast of the pilot hole.While Ca and Sr contents of the extracted brines may be the result of water-rock interaction, Cl is most likely of external origin. The Cl is hypothesized to derive from geotectonic processes rather than to descending infiltration of paleo-seawater (evaporitic brines). The sampled fluids have probably migrated from a deeper reservoir to their present position since the Cretaceous-Tertiary period due to tectonic activity. However, several isotopic studies have identified an admixture of descending paleowaters down to more than 4000 m depth. The high ³⁶ClCl ratio of the fluids sampled during the long-term pumping test point to a host rock highly enriched in UTh, unlike the sampled KTB country rocks. The fluid reservoir is believed to be in contact with the Falkenberg granite massif situated about 2 km to the E of the KTB holes capable of supplying sufficient neutron flux for considerable subsurface production of 36C1. The NaCl(K, SO₄) precursor fluids of the CaNaCI brines were produced in the course of extensive tectonic processes since the Late Caledonian within the Bohemian Massif.     

Nd-Sr isotopic and trace element study of rocks and fluids from the continental deep drilling Project (KTB), Germany

Geochemical analyses were interpreted on the dominant lithological units and on a deep crustal fluid from the Continental Deep Drilling Project (KTB) Pilot Hole, situated at the western margin of the Variscan Bohemian Massif. The biotite gneiss (from 384 m depth) shows a rare earth element pattern very similar to the European shale composite with Nd model ages of 940 Ma (CHUR) and 1.4 Ga (DM). The lamprophyre dike in the upper profile (1549 m), a nepheline and olivine normative basalt, is geochemically and isotopically similar to rocks from the Tertiary Central European Volcanic Province. The lower metabasite sequence (3575–4000 m), with an intrusion age of approximately 500 Ma, is made up primarily of highly metamorphosed subalkalic olivine basalts. The geochemical characteristics of the metabasites are a (La/Yb)_N of 5–10, an La concentration of 20–50 times chondrite as well as (⁸⁷Sr/⁸⁶Sr)_i of 0.7035–0.7038 and _Nd(T) of 4–6. These values suggest a depleted mantle source for the igneous precursors, evolving by assimilation-fractional crystallization processes with up to 25% of upper crust into the ultramafic, basaltic, and intermediate rock types of the metabasite sequence. The strong geochemical and chronological similarities between the KTB metabasites and rocks from the Münchberg Massif suggest that these units belong to the same lithological complex. The high salinity as well as the radiogenic ⁸⁷Sr/⁸⁶Sr ratio of 0.709413 in the KTB fluid from 4000 m depth might be the result of migrating fluids reacting with the regional Permo-Mesozoic evaporite deposits, followed by extensive Sr isotopic exchange with the upper crust.     

中国大陆科学钻探终孔及研究进展

中国大陆科学钻探工程经过1309天的努力奋斗，于2005年1月23日，钻井终孔深度达到5118．20m。成为中国钻探技术发展的新里程碑。全面研究正在开展，在巨量物质深俯冲、超高压深俯冲与折返的精确定年、超高压岩石的原岩形成背景、上地幔流变学、地幔特殊新矿物发现、地下流体异常及地下微生物发现等方面已取得重要进展。     

中国大陆科学钻探工程项目进展综述

阐明了中国大陆科学钻探工程的意义与目标，论述了工程建设的主要内容和项目的组织管理，介绍了项目的进展情况。     

中国大陆科学钻探工程进展

经过12年锲而不舍的努力,中国大陆科学钻探工程终于成为国家级大科学工程及国际大陆科学钻探工程项目.直接观察陆壳的"大陆科学钻探"是伸入地球内部的"望远镜",是具有划时代意义的地学高科技系统工程,是解决人类发展所面临的资源、灾害和环境三大问题的重要手段之一,是继人类登月后向地球的又一次挑战!     

Deep Continental Scientific Drilling Engineering Project in Songliao Basin: progress in Earth Science research

The Songke No.2 well (eastern hole) (referred to as Well SK-2), one of the “two wells and four holes” of the Deep Continental Scientific Drilling Engineering Project in the Songliao Basin, is in Anda City, Heilongjiang Province, and was officially completed on May 26, 2018. The scientific goals of Well SK-2 cover four aspects: paleoclimate research, resource and energy exploration, primary geological research, and development of deep earth exploration techniques. Since the official commencement of drilling in 2014, the Well SK-2 scientific drilling engineering team has organized and implemented drilling for coring, in situ logging, chemical analysis of core elements, and deep structural exploration around the well. Currently, the following preliminary scientific research progress has been made: 4334.81 m in situ core data has been obtained; the centimeter-level high-resolution characterization of the most complete and continuous Cretaceous continental strata ever unearthed has been completed, and the standard profile of continental strata has been initially established; the unconventional natural gas resources and basin-type hot dry rocks in the deep Songliao Basin were found to have good prospects for exploration and development; the climatic evolutionary history of the Cretaceous continental strata was rebuilt for the first time, covering hundreds of thousands to millions of years, and the major events of Cretaceous climate fluctuations have been discovered; all these reveal strong evidence for the subduction and aggregation of paleo-ocean plates, providing a theoretical basis for the re-recognition of the genesis of the Songliao Basin and for deep earth oil and gas exploration. The implementation of the Deep Continental Scientific Drilling Engineering Project in the Songliao Basin is of great significance for exploring the mysteries of the Earth and solving major problems such as those related to the deep energy environment. It is a solid step along the road of “going deep into the Earth”.     

Fluid Geoanalysis in the Chinese Continental Scientific Drilling Project

Mass spectrometry and chromatography were used in the on-line and in situ analysis of fluids in the Chinese continental scientific drilling project. The drilling processes and mud have great effects on the identification of fluids. After considering the effects of air components and artefacts on the deep fluids, we have found that in some segments, helium, methane and carbon dioxide are the main gas components that should originate from the deep Earth. The correlations among gas components are discussed and the fluid profiles in the hole are presented.     

大陆科学深孔取心钻进技术述评

文章介绍了目前世界上大陆科学深钻项目中采用的典型的取心钻进技术及其应用效果,提出了评价科学深钻取心技术的准则,即施工安全性、取心效果、施工效率和施工成本。根据这些准则对目前世界上主要的科学深钻取心技术进行了评价并得出结论：孔底马达/液动锤/金刚石钻进/提钻取心方法是最好的深孔取心钻进方法。     

中国大陆科学钻探工程简介

随着航天技术的发展开辟了人类通往宇宙星际的大门,一个与之相呼应的“入地“计划应运而生,这就是直接观测地球陆壳的“大陆科学钻探”。作为伸入地球内部的“望远镜”,大陆科学深钻是当代地球科学具有划时代意义的大科学工程,是解决当代人类面临的资源、灾害和环境等重大问题的重要途径之一。 由于大陆科学钻探对当代经济、社会发展和科学进步具有重大意义,自70年代以来,俄、德、法、日、美和英等国家实施了大陆钻探,取得令人瞩目的科学研究成果,并带动了钻探和相关科学技术的大发展。     

国际深部大陆科学钻探装备研究进展

大陆科学钻探是获取地下实物信息的唯一手段, 具有钻进地层条件复杂、取芯要求特殊、对钻探工具及装备要求高等特点。美国和德国的先进钻探装备代表了国际深部钻探装备的发展方向; 近十年来, 国内深井和超深井钻机研制取得了较快发展; 本文着重分析了美国NOV理想钻机、德国海瑞克TI-350全液压钻机、中国“地壳一号”万米钻机。国际大陆科学钻探装备关键技术包括顶部驱动钻井技术、钻探装备自动化技术、钻探装备信息化技术。顶部驱动钻井技术利用顶驱装置取代孔口转盘驱动钻杆回转, 钻井作业的能力和效率得到显著提高; 钻探装备自动化技术以实现安全、可靠、高效地运移及拧卸钻具为目的, 主要包括自动猫道、自动摆排管装置和自动上卸扣装置; 钻探装备信息化技术是伴随着现代机电液一体化控制技术和随钻测量技术发展起来的, 通过对地面与井下数据的联合分析, 实现数据综合解释和自主钻进。未来深部大陆科学钻探装备的研制应秉承安全、可靠、高效、节能、舒适的设计理念, 以实现自动化、智能化、信息化钻井为发展目标。     

我国大陆科学钻探工程实施概况及其取心钻进技术体系

科学钻探是为包括构造运动、气候变迁、火山喷发、地震机理、陨星撞击等基础地学研究领域,提取地球深部信息、建立地下长期观测网络的科学工程。开展科学钻探,不仅将促进我国地学基础理论研究走向国际前沿,实现从地质大国向地质强国的转变,还具有拉动我国钻探工程整体进步,提高其技术、学术水平和国际地位的工程技术意义。在通过科学钻探获取的地下信息中,岩心是直接反映地球演变历史的实物资料,也是最为地质学家所重视的研究资料。我国自2001年启动大陆科学钻探工程以来,素以全过程连续钻取岩心和对岩心的高质量要求著称于世。本文概略介绍了我国已成功实施的4项大陆科学钻探工程,着重介绍了在工程中形成的,具有我国自主知识产权的科学钻探取心钻进技术体系：井底动力取心钻进系统、大口径长回次钻程取心钻进系统、极复杂地层原状取心钻进系统,以及各类岩心的无损出管方法,介绍了各钻进系统在工程应用中取得的主要成果。     

中国大陆科学深钻发展的若干思考与建议

科学钻探是获取地球内部信息的最直接和最重要手段,在解决“向地球深部进军”战略科技问题上起着无可替代的作用。本文简要回顾国内外大陆科学钻探的发展历程和深钻的发展现状,分析大陆科学深钻发展特点与态势;围绕中国大陆科学深钻,梳理其关键科学技术问题、面临的挑战与机遇;在此基础上提出中国大陆科学深钻发展的目标、优先发展方向与发展途径建议。大陆科学深钻能够为地球动力学过程、地质灾害、地质资源和环境变化等全球关注的地球科学前沿问题提供独特的研究途径,但是其实施深度又受超高温和超高压等恶劣井眼环境的制约;现代科学技术的进步有力促进了大陆科学深钻中各项技术的发展,为超深井和特深井科学钻探提供重要支撑。中国大陆科学深钻应以9000～15000 m特深井为目标,注重“超深”“深时”和“深观”等领域的科学问题,优先发展地球深部构造、深部生命、深时气候和深部资源探测等方向,研究超深物质、动力学过程和岩石物理等实验技术,研发超高温超高压环境下的钻井、测井和长期观测等技术与装备,促使我国深地探测能力和水平实现一次飞跃。     

松辽盆地白垩系大陆科学钻探松科2井钻遇地层界面及岩性剖面预测

在松辽盆地白垩纪大陆科学钻探松科2井实施前,以钻井地质设计为基础,结合区域地层特征、地球物理资料和邻井钻探结果,参照油气勘探生产标准和经验,对松科2井钻遇主要界面深度进行预测,建立基本框架,同时预测全井段岩性序列、可能的油气水情况和故障层段,最终建立松科2井综合模拟柱状图。各主要地层界面预测深度为:嫩江组二段顶面(T_06)950m,姚家组顶面(T_1)1 245m,泉头组顶面(T_2)1 680m,登娄库组顶面(T_3)2 530m,营城组顶面(T_4)2 965m,沙河子组顶面(T_4-1)3 320m,火石岭组顶面(T_4-2)5 670m,基底顶面(T_5)6 240 m。岩性剖面的预测主要分为两部分:(1)T_4-1之上参考邻井宋深3井钻遇岩性序列;(2)T_4-1之下则根据地震剖面、其他钻遇相当层位的邻井和区域地层特征综合预测。主要目的层岩性特征如下:营城组上部为粗砂岩、砾岩、砂砾岩,下部为厚层凝灰岩、安山玄武岩、流纹岩夹泥岩,底部为砾岩;沙河子组为泥岩夹煤线、细砂岩、粉砂岩和泥质粉砂岩;火石岭组上部为凝灰岩、泥岩、英安岩和安山岩,下部为泥岩夹细-粉砂岩,含煤;基底为极低级或高级成岩的石炭—二叠系沉积地层。松科2井模拟柱状图是钻探工程施工的主要依据,同时也为其他科学钻探工程模拟柱状图的编制提供借鉴。     

苏鲁超高压变质带中国大陆科学钻探主孔(CCSD-MH)榴辉岩中发现金刚石

苏鲁榴辉岩中除了早前发现的一粒金刚石外,最近又发现了6粒,它们具有基本相似的外形和大小,但其晶体结构与普通自然界金刚石和人工合成金刚石存在一定差别.金刚石具有异常X-射线衍射峰以及有磁铁矿的包裹体等特征,表明可以排除这些金刚石是人造或被外来样品混染的可能性.金刚石的再发现,证实苏鲁榴辉岩的形成压力可以达到4GPa以上,并且为大别和苏鲁两个超高压变质带的对比提供了一个重要标志.金刚石的异常晶胞参数和X-Ray异常峰的出现有可能与超高压变质作用有关,但需要实验岩石学研究证实.     

中国大陆科学钻探（CCSD）主孔石榴石橄榄岩中发现Fe2P合金矿物

在东海大陆超深钻(CCSD)的钻孔橄榄岩岩屑(孔深603-683米深部)中,分离出的矿物有硅酸盐、氧化物、硫化物、碳化物、自然元素、金属互化物和合金,计50-60种矿物。多种特征表明其中有一些不寻常矿物,并且有些矿物具有球状外形,如自然铁、镍纹石、铁镍合金、磁铁矿等。本文报道通过成分和结构分析鉴定出的铁磷合金矿物(Fe,P),成分中含少量Cr,Ni和Co,成分均一,分子式为(Fe1.80Ni0.05Cr0.02)P。EDXD数据表明该矿物的晶系属六方晶系;格子类型为P;空间群为P62m;晶胞参数a=b=5.877Ac=3.437A,a:c=1:0.5848。通过ICDDPDF-2x射线粉晶衍射数据库2004年公布的最新版本搜索查询,发现与人工合成的同种矿物Fe2P(ICDD83-2337,Barringerite.syn)十分接近,类似的矿物已在陨石中发现(FeNi)P,故确定本文报道的铁磷合金(Fe2P)为地球上首次发现的天然合金矿物。其成因和形成条件的研究正在进行中。     

中国大陆科学钻探（CSDC）的新进展

中国大陆科学钻探筹备工作展迅速，实先导孔施工技术方案，技术路线以及钻探技术科研项目。     

中国大陆科学钻探工程的科学目标及初步成果

中国大陆科学钻探工程的主孔位于苏鲁超高压变质带南部的东海县,其穿过的岩石曾位于板块会聚边界的地幔深处,是研究大陆深俯冲及地幔动力学的最佳地区。中国大陆科学钻探的科学目标旨在通过对钻孔中获取的全部连续岩心、液态和气态样品及原位测井数据进行的全方位测量与综合研究,建立5000m孔深的各类多学科精细剖面,再造北中国板块与扬子板块会聚边界深部三维物质的组成和分布及三维结构构造;阐明板块会聚边缘的深部流体作用、壳一幔相互作用及地幔中物质循环和流变学;寻找超深地幔条件下形成的特征矿物,揭示超高压变质成矿机理;建立结晶岩地区地球物理理论模型和解释标尺;揭示超高压变质岩石的形成与折返模型及板块会聚边界的深部动力学机制。通过5km深孔营造的特殊地下空问,研究现代地壳的物理、化学及生物作用,并将建立亚洲第一个大陆科学钻探深孔长期观察实验站。中国大陆科学钻探工程已取得初步成果。主孔2000m岩心的深度和方位准确归位;建立了岩性、地球化学、构造、矿化、岩石物性、地下流体及各类测井等精细剖面;揭示了发现除超镁铁质岩外的各类岩石中的柯石英;通过SHRIMP测年准确确定超高压及退变质事件的年龄;初步揭示了超高压及退变质过程中流体的变化及水一岩作用;划分了构造岩片单元,确定了其边界的韧性剪切带性质,并发现早期构造信息;建立的随岩性变化的弹性波速度和热导率连续剖面对地震反射和热结构提供了岩石物性的制约;VSP地震剖面揭示了孔区深部的构造岩片结构,以及强地震反射层和大型韧性剪切带有关;发现地下特殊气体一甲烷、二氧化碳及氦气的异常,以及气体异常越往深部越频繁出现的规律。经DNA分析,在超高压岩心中发现在极端条件下形成的微生物。     

中国大陆科学钻探工程网络拓扑结构与管理信息系统简介

笔者简要介绍了中国大陆科学钻探工程在北京和江苏省东海县钻井现场3个局域网的需求分析、网络拓扑结构及互联方案，并以中国大陆科学钻探工程信息系统为例，给出了一个基于C／S和B／S混合结构的管理信息系统的集成方案，总结了该工程中网络建设与维护的相关经验。     

中国大陆科学钻探工程卫星孔 CCSDPP6 钻孔橄榄岩岩石学研究

中国大陆科学钻探工程卫星孔PP6钻孔位于苏鲁超高压变质带的山东荣成滕家集马草夼橄榄岩体中。该橄榄岩出露于元古代花岗闪长片麻岩中,面积为300m×130m。地表岩石风化强烈,钻孔内岩石新鲜,劈理发育。孔深196m,橄榄岩厚度约110m,下部为花岗闪长片麻岩。橄榄岩主体呈块状构造,边缘呈条带状构造,靠近片麻岩的橄榄岩蛇纹石化强烈。除了10cm厚的岩脉原岩为岩浆分异的产物外,岩石主元素、微量和稀土元素地球化学显示,原岩为极亏损的地幔方辉橄榄岩。岩石主要矿物组成为橄榄石(85%~95%) 斜方辉石(3%~5%) 角闪石(3%~5%) 尖晶石(约0.5%) 镍硫化物(<0.1%),个别部位含有石榴石、单斜辉石和白云石。根据矿物的结构和成分,大体分为三个期次的组合。早期残余地幔矿物组合,由镁橄榄石、富铝顽火辉石、铬尖晶石和透辉石组成,具残余斑状结构,常含有包体,为高温低压组合;超高压变质期矿物组合,由镁橄榄石、镁铝榴石(Pyr=62~66)、低铝顽火辉石、铬尖晶石组成,具细粒变晶结构,无包体,变质温压为840~940°C、3.0~4.1GPa;麻粒岩相─角闪岩相变质期矿物组合,包括韭闪石、镁铝尖晶石、铬尖晶石、白云石、透闪石、蛇纹石,变质温度和压力为650~780℃、<1.8GPa。马草夼橄榄岩作为地幔楔,在印支期发生了超高压变质作用,并在折返过程中叠加了麻粒岩相-角闪岩相的变质作用。