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。     

Effect of fluid column dynamics on longitudinal vibrations of an ultra deepwater riser covered by an orifice plug

The paper studies longitudinal vibrations of an ultra-deepwater drilling riser whose bottom end is disconnected from the sea floor and covered by a plug (a blind one or the one with a hole). An elastic shell is used as a model of a riser pipe. The fluid column motion in the riser is described by the Navier–Stokes equation for a compressible fluid. Losses of fluid pressure during its flowing through a hole in the plug are taken into account. Solution of the riser equations is carried out in the frequency domain. Analysis of the effect which the riser length, wave period and height, and the plug-hole diameter on the amplitude of the riser's tension vibrations is conducted. A riser manufactured of strong aluminium alloys, some of prospective materials for ultra deepwater drilling, was considered as a prototype. It has been shown that risers 2000–4000 m long, plug-hole, and a riser 6000 m long with plug-hole of 0.087 m in diameter can withstand wave height of >15 m throughout the frequency range.     

Volcanic stratigraphy of DSDP/ODP Hole 395A: An interpretation using well-logging data

Deep Sea Drilling Project/Ocean Drilling Program Hole 395A was drilled approximately 500 m deep into young oceanic crust west of the Mid-Atlantic Ridge. Core recovery is very poor in this hole and therefore continuous downhole measurements are important to understand the drilled lithology. Geophysical downhole measurements were carried out during several cruises. A new set of logs was recorded during Leg 174B in summer 1997. The new logging data show a significant improvement in data quality compared to older measurements from Leg 109. The lithostratigraphy established from cores gives only limited information because of the poor core recovery in this hole. The gaps in the core lithostratigraphy are filled by reconstructing a synthetic lithological profile using the standard well-logging data. Three types of lava morphologies, massive basalts, altered lava flows, and pillow basalts, may be distinguished using the logs because the lava morphologies show differences in their physical properties due to differences in fracturing and alteration. The synthetic lithological profile gives a more detailed and precise vertical definition of single layers than the core profile. The integration of further logging and core data enables a detailed reconstruction of the accretion history at the drill site. Cyclic, upward decreasing trends in the resistivity logs were already observed during earlier cruises and were referred to magmatic cycles. Similar trends occur in the density log and, inversely, in the total gamma ray log. The trends reflect gradual changes in fracturing, porosity, permeability, and alteration and cover depth intervals of several tens of meters. Boundaries between cycles are interpreted to correspond to periods of volcanic quiescence. Two types of boundaries may be identified. Boundaries correlating with reversals in the magnetic field and/or changes in the geochemical composition of the basalts are interpreted as long pauses. Basalts separated by these boundaries were probably fed by separate magma reservoirs. Boundaries identified only by changes in alteration but not in geochemistry are interpreted to represent shorter pauses. They separate basalts that were probably fed by the same magma chamber. This revised version was published online in November 2006 with corrections to the Cover Date.     

Metamorphic P–T conditions and thermal structure of Chinese Continental Scientific Drilling main hole eclogites: Fe–Mg partitioning thermometer vs. Zr-in-rutile thermometer

Core rocks recovered from the main hole (5158 m deep) of the Chinese Continental Scientific Drilling (CCSD‐MH) project, southern Sulu UHP terrane, east‐central China, consist of eclogites, various gneisses and minor metaperidotite cumulates; this lithological section underwent subduction‐zone UHP metamorphism. Coesite‐bearing eclogites are mainly present between the depths of 100–2000 m, but below 2000 m, mafic eclogites are rare. Selected elements (Zr, Nb, Cr, Fe, Si, Mg, Al & Ti) in rutile from 39 eclogite cores from 100 to 2774 m, and major elements of minerals from representative eclogites were analysed by electron microprobe. Zirconium and Nb concentrations of rutile cluster ～100–400 and 200–700 ppm respectively. However, Zr and Nb contents in rutile from strongly retrograded eclogites show larger variations than those of fresh or less retrograded eclogites, implying that somehow fluid infiltration affected rutile chemistry during retrograde metamorphism. Zr contents in rutile inclusions in garnet and omphacite are slightly lower than those of the matrix rutile, suggesting that the rutile inclusions formed before or close to the peak temperature. The P–T conditions of the CCSD‐MH eclogites were estimated by both Fe–Mg exchange and Zr‐in‐rutile thermometers, as well as by the Grt–Cpx–Phn–Ky geothermobarometer. The maximum temperature range of 700–811 °C calculated at 40 kbar using the Zr‐in‐rutile thermometer is comparable with temperature estimates by the Fe–Mg exchange thermometer. The temperature estimates of eclogites in a ～3000 m thick section define a continuous gradient, and do not show a distinct temperature gap, suggesting that the rocks from 100 to 3000 m depth might belong to a single, large‐scale UHP slab. These data combined with P–T calculations for CCSD‐MH peridotites yield a low geotherm (～5 °C km^?1) for the Triassic subduction zone between the Sino‐Korean and Yangtze cratons; it lies ～30–35 mW m^?2 conductive model geotherm.     

Evidence for Amazonian acidic liquid water on Mars—A reinterpretation of MER mission results

The Mars Exploration Rover (MER) missions have confirmed aqueous activity on Mars. Here we review the analyses of the field-based MER data, and conclude that some weathering processes in Meridiani Planum and Gusev crater are better explained by late diagenetic water-rock interactions than by early diagenesis only. At Meridiani, the discovery of jarosite by MER-1 Opportunity indicates acidic aqueous activity, evaporation, and desiccation of rock materials. MER-based information, placed into the context of published data, point to local and limited aqueous activity during geologically recent times in Meridiani. Pre-Amazonian environmental changes (including important variations in the near-surface groundwater reservoirs, impact cratering, and global dust storms and other pervasive wind-related erosion) are too extreme for pulverulent jarosite to survive over extended time periods, and therefore we argue instead that jarosite deposits must have formed in a climatically more stable period. Any deposits of pre-existent concretionary jarosite surviving up to the Amazonian would not have reached completion in the highly saline and acidic brines occurring at Meridiani. MER-2 Spirit has also revealed evidence for local and limited Amazonian aqueous environmental conditions in Gusev crater, including chemical weathering leading to goethite and hematite precipitation, rock layering, and chemical enhancement of Cl, S, Br, and oxidized iron in rocks and soils. The estimated relative age of the impact crater materials in Gusev indicates that these processes have taken place during the last 2 billion years. We conclude that minor amounts of shallow acidic liquid water have been present on the surface of Mars at local scales during the Amazonian Period.     

地下工程有害气体静压勘探方法简介

通过"杭州地铁一号线"地下有害气体勘探反复实践,本文从勘探工艺原理、流程及操作要点、材料与设备、质量安全控制等方面总结出一套可以定量获取有害气体埋藏深度、压力大小等相关信息的设备装置和技术方法。本方法具有设备简单轻便、操作方便快速、成本低廉等特点,适用于沿海地区、古河口处大中型地下工程(如深基坑、地下隧道等)有害气体专项勘察。     

桂中坳陷海相地层油气成藏与热作用改造

桂中坳陷是在加里东运动基础上形成的晚古生代海相大型沉积坳陷,已演化成为由上古生界和三叠系充填的残留盆地,其中泥盆系深埋地腹,是主要的勘探目的层系。桂中1井揭示泥盆系—石炭系具有两套生储盖组合,钻遇了气测异常、油迹砂岩、固体沥青等三类油气显示,其中泥盆系沥青显示井段累计709m。桂中坳陷古油藏(沥青)主要来源于中—下泥盆统塘丁组和罗富组泥岩。桂中1井和南丹大厂储层固体沥青为运移/成藏的油气发生热裂解而形成的焦沥青。桂中1井经历了两期油气充注,第一期为印支期前的主力生烃期,第二期(晚期)为燕山期—喜马拉雅期,以紧邻油气显示层的可溶烃类为代表。经历了三期油气改造:第一期为印支期前的油气藏经历了地层沉降增温的热裂解作用而演化为固体沥青和甲烷天然气,第二期为燕山晚期岩浆活动导致的更高温度的热蚀变作用,第三期为喜马拉雅期构造抬升的改造或破坏作用对上泥盆统油气藏的影响。晚期成藏的天然气应是下一步的勘探方向。桂中坳陷西部地层保存相对完整(目的层深埋),断裂和岩浆活动相对不发育,可能更有利于天然气的聚集和保存。     

柴东地区霍布逊坳陷地下水系统研究

运用水文地质系统理论，对柴东地区霍布逊坳陷深积盖层地下水亚系统进行了研究，着重分析了控制地下水系统的水文地质结构系统。结合同位素成果分析，认为该亚系统具良好的层间氧化带砂岩型铀矿成矿的水文地质条件，并指出了成矿有利地区。     

钻井冲洗液对水井出水量影响规律的模拟试验研究及其应用

钻井冲洗液是影响水井出水量的主要因素之一。通过室内模拟试验，发现了不同钻井冲洗液类型和不同洗井方法对含水层渗透性的影响规律，找到了既有较好护壁性又对含水层有较小封堵作用且封堵后易于冲洗的冲洗液，并对聚合物在含水层中的作用机理进行了初步探讨。同时介绍了两个应用实例。     

Provenance of a prominent sediment drift on the northern slope of the South China Sea

The sedimentation rate of the sediment drift in the southeast of Dongsha Islands is as high as 49 cm/ka in the last 1.05 Ma. Although the sedimentation rate changes with time, the contents of rare elements of the sediments remain almost the same, indicating that the source area of the sediments has been constant with time. On the triangular diagrams of La-Th-Sc and Th-Sc-Zr/10, the samples from the southeast of Dongsha Islands fall within the continental island arc field, overlapping the samples from Taiwan, while the samples from the Pearl River, those from the west of the Philippines that contain volcanic material, are separated from them. This indicates that the sediments from the southeast of Dongsha Islands have a close relationship to those from Taiwan in terms of provenance. In fact, the sediments on the northern slope of the South China Sea were derived from northeast direction, as well as from Taiwan, most probably transported from Taiwan through Penghu channel into the South China Sea. The terrigenous part of the deep-sea sediments in the north of the South China Sea was provided by different sources.