Results 61 to 70 of about 3,342 (167)
Jianzhu Gangjiegou Jinzhan, 2022 为研究双轴对称型钢混凝土构件的复合受扭性能，以配钢形式、箍筋间距、混凝土强度、轴压比、扭弯比为变化参数，完成了10个型钢混凝土试件的单调加载试验。研究了压弯剪扭复合受力下构件的破坏形态、扭率-扭矩曲线，并以叠加原理为基础，探讨双轴对称型钢混凝土构件在扭矩作用下的开裂扭矩和极限扭矩计算。结果表明，试件均经历了开裂荷载前的弹性阶段、弹塑性阶段和峰值扭矩后的破坏阶段；10个试件最终呈扭型破坏；闭合角钢桁架混凝土构件受扭承载力明显优于实腹式十字形型钢混凝土构件；轴压比从0.1增加到0.2 ...
杭子彦, 邵永健
doaj
Research on adaptive control of self-moving temporary support based on fuzzy PID [PDF]
To address the issue of poor adaptability of self-moving temporary supports and roofs during roadway excavation, an adaptive control method of self-moving temporary support based on fuzzy PID was proposed.
HUANG Yubo +6 more
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Research and application on megawatt level intelligent fracturing pump system in coal mine [PDF]
This paper presents the development of a megawatt-scale intelligent fracturing pump system for underground coal mines, designed to address the escalating demands for flow and pressure in large-scale regional fracturing applications, particularly in hard ...
Bo LIU +13 more
core +1 more source
Shiyou jixie, 2015 页岩气井可通过电缆射孔与机械封隔器层间封隔，通过依次投球，打开压裂滑套，实现多级压裂改造。但是该技术需要下球座投球封堵影响到采油通道的直径，且下入开关工具的时候均需要精确定位，无法很好满足目前页岩气井压裂的发展需求。为此，通过工艺分析，研制了液压式滑套开关工具来配合固井水泥+开关滑套多段压裂技术使用，并对此液压开关工具进行了三维设计，结构有限元分析和流动分析，验证了该工具结构的合理性。试验测试结果表明，该工具可在较小压力下实现滑套的打开和关闭，其设计原理正确，技术性能可靠，现场操作方便 ...
周传喜 +6 more
doaj
A phase transition-induced fracturing permeability enhancement technology using carbon dioxide capsules for low-permeability coal seams and its application [PDF]
Objective and Methods To address engineering challenges like high gas content, high pressure, and low drainage efficiency in the mining of low-permeability coal seams, this study developed a phase transition-induced fracturing and permeability ...
Hui FU, Mao LI, Xinchuan FAN
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Shiyou jixie, 2015 在多级压裂过程中有效的层间封隔至关重要，水力喷射压裂技术利用水力射流形成的低压区来实现层段间的封隔，但是在井下复杂环境下很难通过试验来定量分析水力封隔效果。鉴于此，首先建立了包含喷嘴、射孔孔道和环空段等结构的CFD模型，模拟了多级水力喷射压裂过程中环空的特性，并将数值模拟结果与试验数据进行对比，验证了该数值模型的正确性；然后根据环空流动特性，提出了用2个出口的质量流量比来评价多级压裂中水力封隔效果；最后，分析了不同参数对封隔效果的影响规律。模拟结果表明：①在一定条件下，高速射流能产生有效的层间封隔 ...
范鑫 +5 more
doaj
Optimization and application of sand bailing technology for coalbed methane horizontal wells [PDF]
Objective and Methods Coalbed methane (CBM) horizontal wells face challenges such as sand accumulation in completion strings, pipe wall scaling, and pump sticking, leading to declined CBM production or shutdown of these wells.
Bao’an XIAN +10 more
core +1 more source
Shiyou jixie, 2015 鉴于压裂滑套球座在水平井裸眼分段压裂工艺中的重要性，从化学成分、金相组织及性能等方面优选了具有可钻性强、满足工艺要求的QT5-A型球墨铸铁球座材料，提出了一种锥面锥段+球面密封的复合球座流道结构。通过数值分析的方法分析了球面密封结构与锥面锥角对球座耐冲蚀性能的影响。分析结果表明，无论有无球面密封，密封面的冲蚀都不可能避免；对于球面密封球座结构虽然后半部分局部冲蚀严重，但由于前半部分避开了砂粒的冲击导致冲蚀速率极低，从而保障了整体密封效果。因此，具有球面密封结构的压裂球座流道结构具有更高的耐冲蚀性能 ...
马明新 +4 more
doaj
Experimental study and application of hydraulic fracturing in underlying coal seam [PDF]
The coalbed methane resource under goaf is rich, but has not been effectively developed for a long time. Hydraulic fracturing technology stands as an effective means to augment coalbed methane recovery.
Cun ZHANG +7 more
core +1 more source
Commingling production of deep coal-measure gas through hydraulic fracturing: Propagation patterns of induced fractures and their determinants [PDF]
ObjectiveThe commingling production of coal-measure gas represents a pivotal approach to enhancing the single-well production of unconventional gas in China.
Dian LI +7 more
core +1 more source