阀门后盖带压钻孔更换主控阀门技术及其现场试验

针对鄂尔多斯盆地靖边气田部分气井主控阀门存在阀板脱落、丝杆断裂等现象而无法开井生产的问题,考虑气井平行闸板阀门结构特点、阀板材质、气体的系统温度和压力等因素,通过理论计算分析和大量的室内模拟试验,提出了阀门后盖带压钻孔+更换主控阀门的新的技术思路,即通过钻穿阀门后盖,顶开阀板,形成通道后实施带压更换闸阀作业。为此,开展了大量的试验研究,并取得了以下成果:①优化了阀门后盖预钻孔尺寸,制定了合理的带压钻孔程序,并设计开发了一套专门的阀门后盖钻孔装置;②系统地对钻孔装置和钻孔程序的可靠性进行了实验验证和完善,确保了该技术在靖边气田现场的成功试验。现场试验结果表明,与压井更换主控阀门工艺相比,该项技术作业过程安全平稳,具有施工周期短、安全环保、不污染地层等优点,为气井主控阀门带压钻孔更换提供了新方法,也为气井安全生产提供了技术保障。     

烟机设备更新改造的技术经济探讨

通过对设备磨损、技术寿命和经济寿命以及最优更新周期的确定方法的研究 ,对烟机设备更新与改造补偿方式的选择与比较进行了分析 ,建议采用低劣化数值法来确定设备的最优更新周期 ,采用寿命周期费用法进行经济评价来选择新设备 ,采用总成本最少法进行经济比较分析。     

淤泥深基坑底板替换土层支撑护坡桩施工技术

狭窄的城区周边建筑物和道路都很多,基础埋置深度内的土层和地基土大部分为杂填土、淤泥等不良地质土.对于埋深小于7m的深基础,采用底板逐渐替换土层支撑护坡桩施工方案,可有效地控制基础开挖过程中桩身和土体位移.与逆作法和水平网格式钢筋混凝土梁支撑钻孔灌注桩等方法相比,该方案土方和基础施工方便,有利于机械施工,工期短、投入小、...     

Maintenance optimization for subsea oil pipelines

In this paper, the classical PF interval model, proposed for reliability centered maintenance, is used to optimize the preventive replacement policy of a subsea oil pipeline. The pipeline is subject to failure modes that may lead to oil release and pollution of the sea. The proposed replacement policy is based on regular condition measurements of the quality of an internal pipeline coating (lining). Holes in the coating will expose the pipe material (steel) to a corrosive environment. It is, therefore, important to identify holes in the coating and take action before the corrosion penetrates the pipe wall. The model proposed in the paper can be used to determine the inspection interval that minimizes the average maintenance cost per time unit. The model formulation is outlined and illustrative examples are solved. The mathematical evaluation of the replacement policy requires numerous assumptions. These assumptions have to be tailored to the specific application. The assumptions and the data provided are included for illustrative purposes to exemplify potential results that may be obtained by using the replacement policy.     

基于灰色成分替代原理的特殊印刷效果研究

在数码打印机上进行实验,得到CMY三色油墨的灰平衡数据,从而确定CMY三色油墨和K墨的替代关系。根据灰色成分替代原理用CMY三色油墨和K墨制作特殊图案,利用CMY和K墨在可见光和红外波段的光谱响应特性,使一幅图像具有可见光和红外光下两种不同的图像外观,达到防伪印刷的目的。     

国外天然气管道非开挖安装、修复及更换技术

目前,我国天然气管道行业主要面临多数老龄期天然气管道需要修复或更换、天然气管道的建设速度与天然气需求量的增速高度不匹配等问题,如何高效安装、修复和更换天然气管道便成为我国大力推动天然气市场发展需要解决的重点问题。为此,在分析我国天然气管道非开挖安装、修复和更换技术需求的基础上,围绕天然气管道非开挖安装、修复及更换技术,对国外已成熟应用的技术进行了全面介绍,并分析了非开挖系列技术的发展方向。结论认为:(1)天然气管道非开挖安装技术正处于不断改进的阶段,并正在朝着"能够适用于各种类型的土壤、能够铺设更大管径的管道、能够以更快的速度施工"的方向发展;(2)我国目前非开挖修复和更换技术所面临的问题主要体现在缺乏评价管道修复或更换的质量标准、缺乏具有非开挖修复和更换技术经验的设计和施工人员;(3)国外非开挖修复技术已能够适用于城镇燃气中低压管道,但对于高压管道其应用还存在着一定的局限性,因此提高内衬材料强度是解决该问题的关键;(4)天然气管道非开挖检测、安装、修复(或更换)技术需要形成完整的体系,才能更有利于提高管道完整性管理的水平。     

提高置换渣锗品位的工业实践研究

丹霞冶炼厂加压浸出液富集分离镓锗的工业生产中：镓锗富集物中锗的品位波动较大,中和渣中锗含量高,严重制约了锗的高效回收。本文结合丹霞冶炼厂生产实践中遇到的问题,从工艺制度、设备优化二个方面进行了系统的分析和讨论,为丹霞冶炼厂锗富集分离工业生产优化提供了指导。     

含铋高锑冶炼渣浸出液梯级分离回收砷、锑、铋

针对传统锑、铋分离过程中,砷、锑、铋分离不彻底,有价元素回收率不够高等问题,采用还原沉砷、水解沉锑、中和除氯、中和沉铋等方法对含铋高锑冶炼浸出液进行处理,对温度,反应时间等影响条件进行了考察.结果表明,在最佳条件下,通过加入次亚磷酸钠将砷酸根还原为砷单质,最后砷以氧化砷的形式被回收,回收率达到了91.99％;沉砷后液加...     

Improvement in seismic resistance using replacement/counterweight fill method for existing high embankments on inclined ground constructed with various embankment materials

The seismic resistance of existing embankments has become a significant issue as embankments fail frequently because of earthquakes. However, there are only a limited number of methods that can improve the seismicity of these existing embankments. In this study, a new improvement method, called the “replacement/counterweight fill method”, is proposed to improve seismic resistance. Two high embankments, of different materials, were constructed on an inclined ground and the replacement/counterweight fill method was applied to them. A seismic response analysis was performed to investigate the effectiveness of the improvement in seismicity. It was found that the replacement/counterweight fill method reduced the area of shear strain by more than 30%, suppressed the deformation of the embankments, and improved the seismic resistance. Along with the increase in the height of the counterweight fill, the effectiveness of this method increased and the seismic resistance was improved even further. Applying the replacement/counterweight fill method contributed to the improvement in seismic resistance by increasing the mean effective stress inside the embankments, decreasing the specific volume, decreasing the stress ratio (q/p’), and reducing the plastic deformation caused by the increase in the overconsolidation ratio due to unloading during the earthquake. Increasing the height of the counterweight fill was seen to be more effective for suppressing embankment deformation than increasing its width because increasing the height meant that the area of the reinforcement effect would be expanded.