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1.
常珑严 《探矿工程》2015,42(8):6-12,21
水包油钻井液作为一种深井低密度欠平衡钻井液流体,适用于低压低渗透地层的施工。通过调研国内外低密度水包油钻井液的发展状况,进行液体黄原胶水包油钻井液的室内试验。根据钻井液体系的不同,将试验分为5组,试验研究了液体黄原胶不同添加量对各组钻井液体系乳化性和流变性的影响。试验结果表明,随着液体黄原胶量的增加,各钻井液体系乳化性逐渐变好,流变性能得到了改善。通过对试验结果的分析,优选出聚磺水包油钻井液体系配方,该体系润滑性比较好,现场施工工艺较为简单;优选出低密度充气钻井液体系配方,该体系适用于欠平衡压力钻井,能够有效地保护储层。  相似文献   

2.
为改良黄土强度低、易变形破坏的工程特性,在黄土中掺加黄原胶和玄武岩纤维,通过无侧限抗压强度试验探究黄原胶含量和玄武岩纤维加筋率及养护龄期对黄土抗压强度的影响。试验结果表明:与素土相比,分别掺加黄原胶和玄武岩纤维均能提高土体抗压强度和一定程度延性;混合掺加黄原胶和玄武岩纤维时,土体的抗压强度和延性都会提高明显。根据正交试验得到,掺加1.5%黄原胶和0.6%玄武岩纤维时,改良土体的抗压强度最大。  相似文献   

3.
The carbonate (CO 3 ?2 ) produced by Sporosarcina pasteurii was injected electrokinetically to enhance the mechanical properties of soft clay soils. In this method the Ca2+ was injected into the anode chamber and moved towards the cathode by electromigration and electroosmotic flow. Then the released CO 3 ?2 from a blend of bacteria and urea was injected into the cathode chamber. The CO 3 ?2 ions were moved from the cathode to the anode under electromigration mechanism. The CaCO3 was precipitated in the presence of calcium in porous medium of the soil, and consequently increased the shear strength of the soil. The polarity reversal was applied to have a homogeneous distribution of CaCO3.  相似文献   

4.
表生环境中的地球化学反应速率具有显著的尺度效应.许多地球化学反应的野外观测速率比实验室观测速率要低2~5个数量级,给不同尺度的研究成果的对比和外推造成了极大困难.本文总结了地球化学反应速率随时间和空间尺度变化的影响因素,着重分析了地球化学反应速率的主控过程随尺度变化的现象,以及亚尺度的非均质性造成的尺度效应.最后介绍了几种尺度转换的研究方法.由于地球化学反应速率的尺度效应普遍存在,在对地球化学反应速率进行外推时需要了解它的局限性以及选取适当的外推方法.  相似文献   

5.
表生地球化学是研究地球表层系统的交叉学科,与气候、环境、人类活动等密切相关.随着大数据时代的来临,表生地球化学正面临着新的机遇和挑战.为了给深时数字地球(Deep-time Digital Earth,DDE)科学计划的数据平台建设提供借鉴和参考,文章对现有的表生地球化学领域的数据及其数据库进行了初步调研.结果表明,表...  相似文献   

6.
Expansive clays undergo swelling when subjected to water. This can cause damage, especially to light weight structures, water conveyance canals, lined reservoirs, highways, and airport runways unless appropriate measures are taken. In this study, granulated blast furnace slag (GBFS) and GBFS-cement (GBFSC) were utilized to overcome or to limit the expansion of an artificially prepared expansive soil sample (sample A). GBFS and GBFSC were added to sample A in proportions of 5–25% by weight. The effects of these stabilizers on grain size distribution, Atterberg limits, swelling percentage and rate of swell of soil samples were determined. GBFS and GBFSC were shown to successfully decreasing the total amount of swell while increasing the rate of swell.  相似文献   

7.
In Sweden, knowledge of the location and timing of glacially induced faulting and seismicity is critical to effective engineering of a long-term nuclear disposal facility. To improve understanding and modeling of the complex ice-induced and tectonic stresses associated with glacially induced faulting, field studies detailing the location and timing of movement of such structures are required. Although the fault has not been confirmed in the bedrock, multi-proxy surficial geologic evidence indicates that the recently discovered scarp in Bollnäs is such a structure. Machine-excavated trenches across the scarp reveal landsliding down the scarp and, in one location, faulted and vertically offset fine-grained glacial sediments. The presence of water-escape structures in trenches excavated on a topographic high strongly suggests a co-seismic origin derived from earthquake magnitudes >5.5. Numerous landslides in till exist in the region as well. Four slopes with landslides were examined in detail, and the factors of safety for these slopes indicate stable conditions and suggest a seismic trigger. Basal radiocarbon dates from peat bogs located stratigraphically above the landslides provide minimum limiting ages for the co-seismic landslides. The oldest date indicates sliding prior to 10,180 calendar years before the present. The proposed Bollnäs Fault is 400 km south of the so called Lapland Fault Province. To date, it is the southernmost confirmed glacially induced fault in Sweden. The results of this study are consistent with existing modeling results that indicate fault instability in this region of central Sweden following deglaciation.  相似文献   

8.
Aerobic mineralisation of Corg in surface sedimentsof the deep (>2000 m water depth) eastern Mediterranean Sea has been quantified by analysis of detailedbox core Corg concentration versus depth profiles and the modelling environment for early diageneticproblems MEDIA. The reactive fraction comprises 60–80% of the total Corg reachingthe sediments and is largely oxidised within the surficial 10 cm. A non-reactive C orgfraction (GNR) dominates at depths >10 cm, and makes up20–40% of the total C org flux to the sediments. First-order rateconstants for decomposition of the reactive fraction calculated from theC org profiles range from 5.4 × 10-3 to8.0 × 10-3 y-1 to 8.0 × 10-3 y-1. Total mineralization rates in thesurface sediment are between 1.7 and 2.6 mol C cm-2 y-1 and thus are typical for oligotrophic, deep-seaenvironments. The low fluxes and rapid remineralisation of C org are accompanied by210Pbexcess surface mixed layers which are only 2 cm deep, among the thinnest reported for oxygenated marine sediments.Model results indicate a mismatch between the C org profiles and O2 microprofileswhich were measured onboard ship. This can be attributed to a combination of decompression artefactsaffecting onboard measurement of the O2 profiles or the leakage ofoxygen into the core during handling on deck. Furthermore, the used Db values, based on 210Pb, may not befully appropriate; calculations with higher Db values improve the O2 fits. The surficial sediment13C org values of -22 become less negative with increasing depth and decreasing C orgconcentrations. The major 13C change occurs in the top 3 to 4 cm and coincides with the interval weremost of the organic carbon oxidation takes place. This indicates that the reactive fractionof organic matter, commonly assumed to be marine, has a more negative 13C orgthan the refractory fraction, usually held to be terrestrial. Palaeoproductivity estimates calculated from thesediment data by means of literature algorithms yield low surface productivities(12–88 gC m-2 y-1), which are in good agreement with field measurements of primary productivity in otherstudies. Such values are, however, significantly lower than those indicated by recent productivitymaps of the area derived from satellite imagery (>100 gC m-2 y-1).  相似文献   

9.
铂族元素的表生地球化学研究进展   总被引:2,自引:0,他引:2  
基性-超基性岩及黑色页岩等风化过程中铂族元素发生了活化和迁移。铂族元素在岩体附近土壤、植物和水体等表生介质中的迁移富集特征可以用来寻找岩浆型铂族元素矿床。黑色页岩风化过程中,Os的表生迁移对海洋^187Os/^188Os值上升有重要意义。此外,作为重金属元素,机动车铂族元素催化剂在环境中的释放,也会带来潜在的生态环境和人体健康问题。  相似文献   

10.
江苏王港潮间带表层碳酸盐的沉积特征   总被引:1,自引:0,他引:1  
利用容量法对江苏王港淤泥质海岸潮间带夏季表层沉积物碳酸盐的含量进行测定。结果表明,碳酸盐含量的空间分布呈现出由岸向海方向递减的大趋势;相关分析表明,总的碳酸盐含量与沉积物的平均粒径有比较显著的相关关系(α=0.01);沉积物组分及粒径频率曲线对比分析表明王港潮间带表层沉积物碳酸盐主要富集于细颗粒部分,潮水沟系统和生物作用(尤其是有孔虫)加强了碳酸盐在细颗粒部分的富集。沉积物碳酸盐含量可以作为物源分析的一个指标,王港地区沉积物碳酸盐含量表明该地区沉积物主要来源于废黄河三角洲和现代黄河的输入,长江输入的沉积物较少。  相似文献   

11.
福建沿海地区浅层地下水质量及其影响因素   总被引:1,自引:0,他引:1  
许美辉 《福建地质》2008,27(3):289-295
福建沿海地区3.8万km^2区域内,采集陆地浅层地下水(井水)1206件样品进行测试19种元素中,选择Be、Cd、C1、Cu、F、Fe、Hg、Mn、Pb、Zn等10个元素,采用内梅罗指数法,对浅层地下水的质量进行评价,并探究了影响地下水质量的主要因素。研究结果表明,浅层地下水的质量主要受地质背景条件及地理条件的共同制约。  相似文献   

12.
Dune sands were stabilized using poly(methyl methacrylate) and polyvinyl acetate and examined using physical and mechanical tests. The California Bearing Ratio test was used to measure the engineering properties of the stabilized materials under dry and the wet environmental conditions, revealing the bearing ratio of the improved dune sands. Our results indicate that both polymers have good potential for increasing the strength of dune sands in the dry state and that there is little decrease in the CBR strength in the saturated state in comparison with the dry state, indicating the stiffness and stability of the compounds against moisture. This is an important point to consider for longevity of roads and road repair and maintenance, because good strength of stabilized sand in saturated sand can prevent early destruction of the road caused by demolition or erosion of the road bed during saturation. The results also demonstrate that the optimum added quantity of polymer for maximum effect was 3% by weight and that the curing time for maximum effect was 28 days. The amount of polymer added was very more important factor for improved dune sand California Bearing Ratio strength in comparison with curing time of the stabilized specimens.  相似文献   

13.
样品处理与保存方法对表层沉积物中金属形态分析的影响   总被引:1,自引:0,他引:1  
利用改进的Tessier连续萃取法研究了冷藏、冷冻、冻干、烘干和风干等样品处理与保存方法对表层沉积物中金属形态的影响。结果表明:各样品处理与保存过程对沉积物中Fe、Mn、Cu、Zn及Pb的形态均具有不同程度的影响,其中Fe的形态受其影响最小(<3.3%),Mn的形态受其影响最大(最高可达10.2%);冻干对各金属形态的影响最小(<4.6%);烘干和风干对重金属Cu、Zn和Pb的可交换态(Ⅰ+Ⅱ)和非残渣态(Ⅰ-Ⅴ)分布影响较大,而冷藏、冷冻和冻干的影响相对较小。因此,综合考虑重金属的形态分布及其生物可利用性,冻干是较理想的沉积物样品处理与保存方法。  相似文献   

14.
Summary Three stabilization phenomena, 1: special e.g. hydrothermal conditions, 2: stabilization by replacements of ions, as e.g. Cu and Fe and 3: heterogeneous nucleation as, e.g., by epitaxy are tested for phases in the system Cu2S-CuS2-Bi2S3-FeS-FeS2. Hydrothermal solution and precipitation conditions can metastabilize or stabilize phases, which are not existent under dry conditions as Cu4Bi5S10 or CuS2-FeS2 mixed crystals, but are stable at high pressures. Stabilization by Cu-Fe substitution leads to the assumption that stabilization basically depends on the ionic radii similarity, but necessarily electronic interactions have to be involved. Stabilization by heterogeneous nucleation is tested for Pb-Bi sulfosalts, e.g. for the epitaxial growth of Bi2S3 on NaCl. In contrast to the normal orthorhombic Bi2S3, the epitaxial Bi2S3 shows a pseudotetragonal subcell correlated to NaCl. Satellite reflections indicate a modulation probably caused by a modulation of the metal vacancies.
Stabilisterung von Cu-Fe-Bi-Pb-Sn-Sulfiden
Zusammenfassung Im System Cu2S-CuS2-Bi2S3-FeS-FeS2 werden drei Stabilisierungsphänomene 1: spezielle Stabilisierungsbedingungen z. B. in hydrothermalen Lösungen, 2: Stabilisierungen durch Elemente- bzw. Ionenersatz am Beispiel von Cu und Fe und 3: heterogene Keimbildung anhand von Epitaxieversuchen verifiziert.Hydrothermale Ausscheidungsbedingungen können metastabile oder stabile Phasen bedingen, die z. B. unter trockenen Bedingungen nicht oder nur bei hohen Drucken stabil sind. Dies gilt z. B. für den Cu-Fe-Ersatz in Cu4Bi5S10 bzw. für CUS2-FeS2 Mischkristalle. Die Stabilisierung durch Cu-Fe-Substitution führt zu der Annahme, daß hierfür als notwendige Voraussetzung die Ähnlichkeit der Ionenradien gilt, jedoch als hinreichende Bedingung die elektronische Wechselwirkung zwischen den sich ersetzenden Ionen anzusehen ist.Die Stabilisierung durch heterogene Keimbildung wird für Pb-Bi-Sulfosalze am Beispiel der Epitaxie von Bi2S3 auf NaCI getestet. Im Gegensatz zum normalen orthorhombischen Bi2S3 zeigt die epitaktische Phase eine mit NaCl korrelierte tetragonale Subzelle. Satellitenreflexe deuten auf eine Modulation der Leerstellen der Metallionen hin.


With 10 Figures

Contribution to the Ore Mineralogy Symposium (IMA/COM) at the 14th General Meeting of the International Mineralogical Association, at Stanford, California, in July, 1986.  相似文献   

15.
山西古交矿区钻探施工中遇到严重漏失现象,采用传统的粘土球、水泥球、快干水泥、801堵漏剂加木屑等材料堵漏方法,均无效果,经过摸索和实践,采用聚丙烯酰胺+切削膏进行堵漏,取得了很大的成功,施工效率高、施工成本低、堵漏效果好,同时还减少了钻具的磨损,沉淀了钻渣,净化了冲洗液。  相似文献   

16.
Karstified features and surficial calcareous crust (caliche) develop on the upper most surfaces of the Middle Miocene rocks in the area between Quseir and Mersa Alam along the Red Sea coast, Egypt. Detailed studies of the caliche profile revealed various textures and fabrics denoting a cyclicity in deposition as well as diagenetic differentiation crystallization and deformation. The occurrence of these caliche deposits suggest that the Middle Miocene rocks in the study area have been subjected to alternating periods of rainfall and intense evaporation.
Zusammenfassung Karstphänomene und Kalkkrusten (Caliche) haben sich auf den Oberflächen der Gesteine des Mittelmiozäns im Gebiet zwischen Quseir und Mersa Alam entlang der Küste des Roten Meeres in Ägypten entwickelt. Eingehende Untersuchungen von Kalkkrusten Profilen lassen unterschiedliche Strukturen und Gefüge erkennen, die sowohl zyklische Bildung belegen als auch diagenetische Kristallisations-Differentiation und Deformation. Das Auftreten dieser Caliche-Bildungen legt nahe, daß die mittelmiozänen Gesteine im Untersuchungsgebiet abwechselnd regenreichen Perioden und solchen mit starker Evaporation ausgesetzt waren.

Résumé Des structures karstiques et des croûtes calcaires superficielles (caliches), se sont formées à la surface des roches du Miocène moyen dans la région comprise entre Ouseir et Mersa Alam, le long de la côte de la mer Rouge, en Egypte. L'étude détaillée de profils de la caliche révèle des structures variées qui indiquent un dépôt cyclique ainsi qu'une cristallisation différentielle et une déformation diagénétique. La présence de tels dépôts de caliche suggère que les roches du Miocène moyen de cette région ont été soumises alternativement à des périodes de pluie et d'évaporation intense.

Quseir Mersa Alam — . , , , , . , .
  相似文献   

17.
This study used a mass-balance simulation approach in conjunction with geochemical, mineralogical, thermodynamic and isotopic constraints, to assess the origins of NaSO4(±HCO3) type groundwater and springwater associated with smectitic sulphide-mineral-bearing unconsolidated surficial sediments and the underlying Paskapoo Formation in south-central Alberta. Results indicate that alteration of albite to kaolinite and alteration of kaolinite to Na-smectite are the primary controls on dissolved Na and SiO2 concentrations in groundwater and springwater. Concentrations of dissolved Ca and Mg are controlled by reactions involving carbonate minerals and possibly cation exchange. Dissolved SO4 is generated primarily through oxidation of pyrite. Most H+ generated by oxidation of pyrite is consumed in aluminosilicate alteration reactions. The carbon isotopic composition of CO2 gas required in mass-balance simulations suggests the presence of an isotopically heterogeneous environment with respect to 13C. This apparent isotopic heterogeneity may result from the presence of varying fractions of atmospheric and microbially respired CO2.  相似文献   

18.
以土壤环境地球化学研究为主线,以冀东地区13 472 km2为研究区域,将土壤重金属污染元素镉的空间分布规律与环境地球化学机理研究相结合,建立区域土壤环境地球化学基线,选用合适的判别指标判识自然作用过程与人类活动过程对土壤环境的影响。通过对3 287个样品的镉含量的统计分析,结果表明,冀东地区表层土壤中镉的基线值为0.073 mg/kg,镉元素含量大于0.230 mg/kg的样品可能遭受人为污染的影响。地质累积指数分析结果显示,冀东地区49.0%的表层土壤未受镉污染,47.6%的表层土壤在无污染与中度污染之间,2.1%受中度污染,1.2%的表层土壤介于中度污染到强污染之间,只有1%受强污染。污染程度指数分析则显示,冀东地区94.5%的表层土壤未受到镉污染,98.8%的表层土壤污染程度小于2,总污染程度小于0,即总体未受到污染。  相似文献   

19.
西菲律宾海盆表层沉积物中的轻碎屑分区及物质来源   总被引:2,自引:0,他引:2  
海洋沉积物中轻碎屑(0125~0063mm)种类的特征和分布样式对于沉积物源区的判别具有重要的指示意义。取自西菲律宾海219个表层沉积物样品中的轻碎屑种类包括生物碎屑、石英、长石、褐色火山玻璃、无色火山玻璃、风化碎屑、火山渣,以及含量极低的一些矿物如磷酸盐(鱼牙)、片状矿物(黑云母和白云母)、硅灰石、黑曜石以及极少量的球粒状、椭球状宇源颗粒。分析结果表明,本区的轻碎屑分布可以分为三个区: (Ⅰ)菲律宾海沟以东区,轻碎屑主要源于钙质或硅质生物,邻近的岛弧也贡献了一定量的火山碎屑。(Ⅱ)中部区,石英、长石和无色火山玻璃可能源于中酸性熔岩海山或者是正在活动的中酸性岩浆事件的产物。(Ⅲ) 帛琉—九州海岭以西区,本区的物质来源相对比较复杂。长石、石英的含量较低,可能主要来源于中酸性熔岩海山或者是正在活动的中酸性岩浆事件的产物,火山渣主要是源于喷发在帛琉—九州海岭之上的火山。可以认为:① 研究区的生物碎屑含量与水深紧密相关,生物碎屑的数量主要受控于碳酸盐补偿深度(CCD)。② 来自菲律宾岛弧的火山碎屑对本区沉积作用贡献较小,可能通过海流或风等途径向深海盆进行短距离搬运。海底高原(如本哈姆高原)和邻近海岭(如帛琉—九州海岭)火山岩的风化产物对本研究区轻碎屑沉积作用有着重要贡献,其影响范围主要依赖于海底风化作用的强度。③ 来自中国大陆及菲律宾等邻近岛弧的陆源碎屑物质对本区的沉积作用影响很小。本区可能存在的中酸性熔岩海山是长英质轻碎屑物质的主要源区。  相似文献   

20.
林镇坤  王爱军  叶翔 《沉积学报》2019,37(1):124-134
沉积物粒度分布特征可揭示沉积动力环境。基于广西南流江河口水下三角洲的粒度分析数据,采用Folk分类法进行分类,应用端元分析对其粒度数据进行分解,探讨了南流江河口水下三角洲的物源和现代沉积动力环境。结果表明,研究区表层沉积物可划分为9类,其中含砾沉积物5类,不含砾沉积物4类,沉积物类型与河口环境动力特征相吻合。端元分析结果显示,研究区有5个不同类型的端元,分别代表着5种类型的沉积物动力环境:端元1反映了风浪和潮流对表层沉积物的动力作用;端元2指示了外海涌浪对表层沉积物的作用过程;端元3代表了南流江冲淡水引起的表层沉积物的输运;端元4代表了大陆架残留沉积物;端元5为干扰端元,可能是由于工程建设等人类活动所引起的。利用端元分析探讨复杂环境(如小型山溪性河口)下的沉积动力环境时,一方面需要综合考虑研究区域的物源与环境动力特征;另一方面可以结合参数拟合、粒径趋势分析等研究手段。  相似文献   

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