浅海伸缩套管钻探工艺研究          下载免费PDF全文

王林清  马汉臣  许本冲  殷国乐  陈浩文  秦如雷  卢秋平 《探矿工程》2021,48(7):40-45

浅海取心钻探中钻遇易坍塌地层时,需要下放套管封隔地层,保证泥浆循环,换径继续钻进。现有常规下套管方法为使用带有钻台层甲板和套管层甲板的钻井船进行下放套管作业,部分无套管层甲板钻井船在遇到必须下套管的工况时,需临时搭建套管层平台进行下放套管作业,但受钻机和钻具体积及质量的限制。为解决无套管层甲板的钻井船在海洋钻探取心时需要下入套管的难题,设计了一种海洋钻探下入多层套管的工艺方法,利用可伸缩套管及相关设备,在海底井口与小型钻井船之间建立泥浆上返通道,封隔不稳定地层,实现泥浆回收循环及钻具升沉补偿。在钻井过程中,伸缩套管还可以起到导向定位的作用,防止潮差水流流速变化影响钻具下入,为浅海钻井节省时间和成本。  相似文献   

福建建瓯地区“竹洲砾岩”的厘定     

余心起吴淦国  张达狄永军  林东燕石建基张祥信  汪群峰黄火剑 《地质通报》2006,25(5):580-584

对发育于福建建瓯市迪口镇竹洲村的"竹洲砾岩"的野外调查和室内研究表明,该砾岩既不是前震旦系马面山群龙北溪组的底部砾岩,也不是构造砾岩,而是相当于晚三叠世大坑组(T3d)层位的底砾岩,不整合沉积在前震旦系迪口组之上.这一发现对深化研究该地区前寒武纪地质构造演化历史具有重要意义.  相似文献   

冻融过程中土体水热力耦合作用理论和模型研究进展   总被引：7，自引：3，他引：4  

宋存牛 《冰川冻土》2010,32(5)

随着冻土地区基础设施建设加快,冻害已成为寒区工程建设中迫切需要解决的问题.造成冻害现象的主要原因是土体的冻胀和融沉,而冻融过程受控于土体温度场、水分场、应力场及其变化规律.深入开展水热力耦合作用机理的研究对解决实际工程冻害问题具有重要的指导意义.对国内外在水热力耦合作用机理、耦合作用方程方面的研究进行了综评,指出了各种研究结果之间差异、不同冻胀模式建立的依据、研究方法以及适用条件,分析了目前冻融过程中土体水热力耦合作用理论和模型研究中存在的问题,提出了今后研究发展的方向.  相似文献   

Temporal and spatial variations in periglacial soil movements on alpine crest slopes     

Norikazu Matsuoka 《地球表面变化过程与地形》2005,30(1):41-58

This paper describes up to ten years of continuous monitoring of frost heave, creep and associated parameters on high mountain crest slopes in the Japanese and Swiss Alps, aiming to evaluate spatial and interannual variations in the rates and controls of soil movement. Shallow frost creep re?ecting diurnal frost heave activity dominates the crest slopes that lack a vegetation mat and have a thin debris mantle with good drainage. Seasonal frost heave activity can induce slightly deeper movement where ?ne soil exists below the depth reached by diurnal freeze–thaw penetration, although the shallow bedrock impedes movements below 20 cm depth. As a result, downslope velocity pro?les display strong concavity with surface velocities of 2–50 cm a^?1. The frost creep rates vary spatially, depending on the soil texture, slope gradient, frequency of temperature cycling across 0 °C and moisture availability during freeze–thaw periods. Soil movements recur in every freeze–thaw period, although with some interannual variations affected by the length of seasonal snow cover and the occurrence of precipitation during freeze–thaw periods. The Swiss Alps encounter more signi?cant interannual variations than the Japanese Alps, re?ecting the large variability of the annual snow regime. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

庐山运动   总被引：1，自引：0，他引：1  

毕华  谭克仁 《矿物学报》1997,17(3):291-296

本文简述了庐山隆-滑构造的基本特征。在中元古代双桥山群底部的顺层韧变带中，把前人的断层构造砾或沉积成因的巨厚层状变质复成分砾岩，自上而下分离出三层砾：上部砾、中部砾、下部砾。其中上部砾为断层构造砾；中部砾不是砾，而是构造分泌物；下部砾为沉积底砾。在此基础上，同时参考研究区早元古代星子群与中元古代双桥山群构造、岩浆活动、变质作用等方面的差异，建立了“庐山运动”，其活动时间为2200～1800Ma，这可以与华北及华南其它地区同时期的构造运动相对比，但庐山运动的强度相对较弱，表现为以垂直隆升为特色的造陆运动，它曾使研究区早元古代晚期至少遭受过长达200Ma（1800～1600Ma）的风化、剥蚀作用。  相似文献   

砂-砂砾换基防治渠道冻胀的研究     

朱强  付思宁  武福学 《冰川冻土》1988,(4)

本文依据140组渠道工程上的实测数据,建立了残留冻胀率与换填比间的定量关系,据此得出了在地下水深埋和浅埋两种情况下,不同土质所要求的换填比。同时根据冻胀试验场220组粗粒土敏感性试验资料得出,当冻层与地下水距离大于或小于50cm时,应分别控制砂砾料内含土量不大于10％和5％。文末提出了防治砂砾料被含砂渠水污染及设立排水设施以保证换填防冻效果的两项措施。  相似文献   

大兴安岭北部霍拉河盆地地质构造在冻土形成中的作用   总被引：3，自引：1，他引：3  

郭东信  黄以职  王家澄  王保来  曾仲巩  贺益贤  杨殿文  刘日升 《冰川冻土》1989,(3)

霍拉河盆地周围山地与盆地的发育过程、构造活动方式,以及经受外营力作用不同,致使它们地质结构、沉积岩相、岩性、裂隙发育程度及地下水赋存规律等呈现明显差异。由此形成自盆地中心向四周山地冻土厚度明显变薄、温度升高,到周围山地某些地段出现融区。  相似文献   

The dynamics of western North America: stress magnitudes and the relative role of gravitational potential energy, plate interaction at the boundary and basal tractions     

Lucy M. Flesch  William E. Holt  A. John Haines  Lianxing Wen  Bingming Shen-Tu 《Geophysical Journal International》2007,169(3):866-896

  相似文献   

Mass budgets of the Lambert, Mellor and Fisher Glaciers and basal fluxes beneath their flowbands on Amery Ice Shelf   总被引：4，自引：0，他引：4  

Kenneth C. JEZEK  Beata M. CSATHó  Ute C. HERZFELD  Katy L. FARNESS  Philippe HUYBRECHTS 《中国科学D辑(英文版)》2007,50(11):1693-1706

We used in situ measurements and remote-sensing data sets to evaluate the mass budgets of the Lambert, Mellor and Fisher Glaciers and the basal melting and freezing rates beneath their flowbands on the Amery Ice Shelf. Our findings show the Lambert and Mellor Glaciers upstream of the ANARE Lambert Glacier Basin (LGB) traverse may have positive imbalances of 3.9±2.1 Gt a-1 and 2.1±2.4 Gt a-1, respectively, while the Fisher Glacier is approximately in balance. The upstream region as a whole has a positive imbalance of 5.9±4.9 Gt a-1. The three same glaciers downstream of the ANARE LGB traverse line are in negative imbalance, where the whole downstream region has a negative imbalance of -8.5±5.8 Gt a-1. Overall the mass budgets of the Lambert, Mellor, and Fisher Glaciers are close to bal-ance, and the collective three-glacier system is also nearly in balance with a mass budget of -2.6±6.5 Gt a-1. The significant positive imbalances for the interior basin upstream of the ice-movement stations established in the early 1970s (GL line) reported previously are possibly due to an overestimate of the total accumulation and an underestimate of the ice flux through the GL line. The mean melting rate is -23.0±3.5 m ice a-1 near the southern grounding line, which decreases rapidly downstream, and transitions to refreezing at around 300 km from the southern extremity of the Amery Ice Shelf. Freezing rates along the flowbands are around 0.5±0.1 to 1.5±0.2 m ice a-1. The per-centage of ice lost from the interior by basal melting beneath the flowbands is about 80%±5%. The total basal melting and refreezing beneath the three flowbands is 50.3±7.5 Gt ice a-1 and 7.0±1.1 Gt ice a-1, respectively. We find a much larger total basal melting and net melting than the results for the whole Amery Ice Shelf derived from previous modeling and oceanographic measurements.  相似文献   

RTK高程和Heave信号的融合及精度分析     

阳凡林  赵建虎  张红梅  韩晓冬 《武汉大学学报(信息科学版)》2007,32(3):225-228

对RTK高程和Heave信号在合成之前进行了预处理，确保了短周期内两者监测尺度和时间上的一致；然后利用数字信号处理技术实现这两个信号的融合；并通过一个实验对信号合成方法的精度进行了全面的分析和评估，认为该方法可以达到约6～7cm的精度，将传统多波束数据处理方法的精度提高了1倍。  相似文献