冀中坳陷中部现今热岩石圈厚度及地热学意义探讨

热岩石圈厚度是研究盆地的构造演化和板块动力学的重要参数,本文通过实测数据构建地壳分层模型,根据热传导的基本原理,计算了冀中坳陷中部的Moho面温度以及热岩石圈厚度,并探讨其地热学意义。结果表明:冀中坳陷中部的Moho面温度分布在500～600℃,西南侧整体温度较东北部高,热岩石圈厚度介于102～122km,其平面展布特征与华北克拉通热岩石圈厚度西厚东薄的特征相吻合,为华北克拉通受太平洋板块西向俯冲导致东部遭受破坏提供了依据,并且较薄的岩石圈使热流更易传导到地壳浅部,成为了该地区热异常的成因背景。     

基于高导热材料填充漏失构造的深井换热器性能分析

地热供暖可有效缓解北方雾霾天气。干热岩虽然储量丰富,但增强型地热技术由于开发费用较高,裂隙控制以及避免诱发地震的技术尚不成熟,现阶段还不能商业化应用。水热型地热开发技术虽较成熟,但受资源条件的限制,开发规模较小。对于大多地区,受地质构造和资源禀赋的控制,单井产水量较低或者回灌难,开发经济效益较差。深井换热器(DBHE)技术是开采地热水低产区或回灌难地区热能的有效方式,但受制于岩石导热系数低,单井输出功率小,投资回收期长。为提高DBHE的输出功率,本文提出了增强型深井换热器(EDBHE),通过主动将高导热性能的复合填充剂流进漏失构造的方式提高岩石的导热性能,通过调节回压、密度和黏度来控制漏失量。研究结果表明,单井EDBHE十个采暖季的平均取热功率为1002.34 kW,是DBHE(424.45 kW)的2.36倍。而双井EDBHE十个采暖季的平均取热功率更是达到了27501.61 kW,且热输出稳定,每年的衰减率0.95%。EDBHE技术有效利用了出水量低或回灌难的水热型热储,大幅提高了其出力,扩大了地热供暖的应用范围。     

Relationship of geological and geothermal field properties: Midcontinent area, USA, an example

Quantitative approaches to data analysis in the last decade have become important in basin modeling and mineral-resource estimation. The interrelation of geological, geophysical, geochemical, and geohydrological variables is important in adjusting a model to a real-world situation. Revealing the interdependences of variables can contribute in understanding the processes interacting in sedimentary basins. It is reasonably simple to compare spatial data of the same type but more difficult if different properties are involved. Statistical techniques, such as cluster analysis or principal components analysis, or some algebraic approaches can be used to ascertain the relations of standardized spatial data. In this example, structural configuration on five different stratigraphic horizons, one total sediment thickness map, and four maps of geothermal data were copared. As expected, the structural maps are highly related because all had undergone about the same deformation with differing degrees of intensity. The temperature gradients derived (1) from shallow borehole logging measurements under equilibrium conditions with the surrounding rock, and (2) from non-equilibrium bottom-hole temperatures (BHT) from deeper depths are mainly independent of each other. This was expected and confirmed also for the two temperature maps at 1000 ft which were constructed using both types of gradient values. Thus, it is evident that the use of a 2-point (BHT and surface temperature) straightline calculation of a mean temperature gradient gives different information about the geothermal regime than using gradients from temperatures logged under equilibrium conditions. Nevertheless, it is useful to determine to what a degree the larger dataset of nonequilibrium temperatures could reflect quantitative relationships to geologic conditions. Comparing all maps of geothermal information vs. the structural and the sediment thickness maps, it was determined that all correlations are moderately negative or slightly positive. These results are clearly shown by the cluster analysis and the principal components. Considering a close relationship between temperature and thermal conductivity of the sediments as observed for most of the Midcontinent area and relatively homogeneous heat-flow density conditions for the study area these results support the following assumptions: (1) undifferentiated geothermal gradients, computed from temperatures of different depth intervals and differing sediment properties, cannot contribute to an improved understanding of the temperature structure and its controls within the sedimentary cover, and (2) the quantitative approach of revealing such relations needs refined datasets of temperature information valid for the different depth levels or stratigraphic units.     

郑州金水大道立交桥基础钻孔灌注桩施工实践

文章阐述了郑州市金水路立交桥基础桩工程施工中采用的主要技术装备、工艺、组织管理和施工中几个问题的处理措施。     

应变仪记录的印尼苏门答腊海域7.8级地震的同震信号研究

为进一步研究钻孔应变观测在震源反演和地球结构模型检验方面的可靠性,利用钻孔应变仪记录的印尼苏门答腊海域7.8级地震的同震信号和QSSP软件计算的理论应变图,提取有效的监测数据进行P波震相识别和各震相到时分析,再截取监测数据和理论数据对应部分进行相关性分析并计算互相关系数。结果表明,在震中距36°~52°范围内,监测数据与QSSP理论数据具有较好的一致性。因此,在震中距36°~52°范围内,台站的钻孔应变观测数据可用于震源反演和新的地球结构模型检验,且结果可靠。     

钻孔应变观测原位标定方法研究进展

钻孔应变观测的原位标定是制约钻孔应变定量观测理论与技术发展的基础性问题。为推进钻孔应变观测在地球动力学研究中的应用,从标定模型、参考应变信号等方面系统总结钻孔应变观测原位标定方法研究的最新进展,指出钻孔应变观测原位标定中存在的主要问题,并展望今后的发展方向。     

The structure of the Monte Amiata volcano-geothermal area (Northern Apennines, Italy): Neogene-Quaternary compression versus extension

The tectonic evolution of the Mt Amiata volcano-geothermal area is under discussion. Some authors state that this region, as well as the hinterland of the Northern Apennines, were affected by compression from the Cretaceous to the Quaternary. In contrast, most authors believe that extension drove the tectonic evolution of the Northern Apennines from the Early Miocene to the Quaternary. Field data, seismic analyses and borehole logs have been integrated in order to better define the structural features of the continental crust in the Mt Amiata geothermal area. In this paper I propose the hypothesis that the structure of the crust in the Mt Amiata volcano-geothermal area derives from two main geological processes: (1) contractional tectonics related to the stacking of the Northern Apennines (Cretaceous–Early Miocene), (2) subsequent extensional collapse of the hinterland of the mountain chain, and related opening of the Northern Tyrrhenian Sea (Early Miocene–Quaternary). Compressional and extensional structures characterise the Mt Amiata region, although extensional structures dominate its geological framework. In particular the extension produced: (a) Middle-Late Miocene boudinage of the previously stacked tectonic units; (b) Pliocene–Quaternary normal faulting which favoured the emplacement of a magmatic body in the middle-upper crust; and (c) the eruption of the Mt Amiata volcano, which gave rise to an acid and intermediate volcanic complex (0.3–0.19 Ma). The extension produced the space necessary to accommodate the Middle-Late Miocene marine and continental sediments. Pliocene and Quaternary normal and transtensional faults dissected the previous structures and influenced the Early Middle Pliocene marine sedimentation within the structural depressions neighbouring the Mt Amiata volcano. The magmatic body was emplaced at depth (about 6–7 km) during the Pliocene extension, and produced the eruption of the Mt Amiata volcano during the Late Pleistocene. This gave rise to local uplift, presently reaching about 3,000 m, as well as a negative Bouguer anomaly (−16 mgal), both centred on the Mt Amiata area. The crustal dome shows a good correspondence with the convex shape of the regional seismic marker known as the K-horizon, which corresponds to the 450°C isotherm, and the areas with greatest heat flow. This is probably a consequence of the above-cited magmatic body presently in the process of solidification. A Late Pleistocene eruption occurred along a crustal fissure striking N50° (Mt Amiata Fault), which crosscuts the crustal dome. Hydrothermal circulation, proven by the occurrence of thermal springs and gas vents (mainly CO₂ and H₂S), mainly occurs along the Mt Amiata Fault both in the northeastern ans southwestern sides of the volcano.     

井地磁测资料联合反演及应用

井中磁测离深部场源近,能避开浅部干扰,是一种有效的找矿手段,但其控制范围有限;地面磁测采集方便且控制范围大,但老矿区干扰因素多,深部矿体信号弱,不容易解释.文章充分利用地面和井中磁测资料的优点,以二度板状体模型为例,进行井地磁测资料联合反演.通过数值模拟说明了井地联合反演方法的优越性,同时还比较了马奎特法,广义逆法和遗传算法三种不同算法的优缺点,最后将其应用于大冶铁矿实际资料的处理解释,为危机矿山的深部找矿提供了一种有效的方法.     

天津地区地热钻井及成井技术

多年来,天津地热钻井技术不断发展。天津市地热井施工最深达4041 m,最高井口温度105 ℃,自流水量300 m3/h。针对天津地区不同热储层的钻井工艺技术进行简要介绍,并总结了一些经验教训。     

国道318线二康路K2794滑坡监测

国道318线二康路K2794滑坡监测历时25年,经历了滑坡治理施工前、治理施工中和治理施工后监测3个阶段,为滑坡的治理设计和施工提供了较好的辅助数据,保证了施工设计方案的科学和施工的安全。介绍了其监测设计、监测方法、监测仪器的选择以及监测布置方案等内容,该项目的实施为其他类似滑坡监测积累了经验。