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针对煤矿井下高瓦斯软煤顺层长钻孔排渣困难、成孔率低、施工困难等问题,通过数值模拟实验研究了井下深部软煤体变形破坏特征,分析了顺层长钻孔孔周松软煤体变形特征及应力变化,以揭示顺层长钻孔孔周松软煤体变形产渣规律。研究表明:深部高瓦斯软煤顺层钻孔孔周煤体的应力平衡临界条件破坏后将发生大体积突然垮落;钻孔水平最大变形位移为1.22mm,垂直方向最大变形位移为10.7mm;径向孔周煤体垂向变形呈现逐渐减小趋势,且垂向变形明显大于钻孔水平变形。在水平方向上,钻孔孔周煤体应力分布呈现先增大再逐渐减小的变化规律,径向距离对水平应力分布的影响逐渐减小;随着径向距离的增加,钻孔孔周煤体应力分布逐渐降低,钻孔孔壁处煤体的应力出现最大值,且垂直方向处应力值最大。 相似文献
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云盖山煤矿为煤与瓦斯突出矿井,为探寻更为高效、经济的区域消突措施,设计在1232回风巷掘进期间采用注水防突技术,通过现场试验得到,钻孔松动爆破的有效半径为7m,爆破钻孔注水量为直接注水钻孔的35倍以上,爆破区煤层内含水率明显增大,爆破增注区域的瓦斯放散初速度(q值)和钻屑量(s值)明显减小,证实了爆破增注技术对防治瓦斯突出有显著效果,可采用该技术进行区域瓦斯消突。 相似文献
4.
合理设计岩屑规程保证正常钻进条件——金刚石钻进技术专题之一 总被引:2,自引:0,他引:2
论述了正常钻进的条件,提出了合理岩屑规程是保证正常钻进的关键和设计钻头的主要依据之一,讨论了岩屑规程与金刚石钻头唇面工作状态、孔底表面粗糙度和岩屑粒度的关系,提出了相应的建议。 相似文献
5.
杨春明 《探矿工程(岩土钻掘工程)》1994,(1):10-12
仪器采用双滚筒双排缆绞车及其带绕双根四心铠装电缆,通过双滑轮架井口导问,并定向吊放井下仪器,进行井内检测。其基本原理是利用超声波测距原理,结合计算机等综合性科学检测技术,实现大口径基桩孔的成孔质量检测,即检测其孔径、孔斜和孔底沉碴厚度。 相似文献
6.
本文综合介绍了石油大学钻井环空水力学课题组近10年来所研究的成果。重点介绍了(1)垂直井同心环空中幂律流体及牛顿流体轴向流层流流场的研究,建立了速度、视粘度、排量及压耗等模式;(2)垂直井同心环空中纯粘性流体螺旋流层流流场的理论分析;(3)定向井偏心环空中幂律流体流动规律及宾汉流体轴向流层流流场的研究;(4)定向井及水平井岩屑运移机理与规律的研究,从实验架上实际观察得出了反映岩屑运移机理的四种流动物理模型,分析了影响岩屑运移的因素;根据双层理论导出了大斜度井岩屑床厚度的理论模式,并通过大量室内实验得出了大斜度井及水平井段岩屑床厚度的经验模式,这些研究成果都得到了现场的验证,并成功地应用到走向井钻井施工中。 相似文献
7.
Remediation of groundwater contaminated with MTBE and benzene: the potential of vertical-flow soil filter systems 总被引:1,自引:0,他引:1
van Afferden M Rahman KZ Mosig P De Biase C Thullner M Oswald SE Müller RA 《Water research》2011,45(16):5063-5074
Field investigations on the treatment of MTBE and benzene from contaminated groundwater in pilot or full-scale constructed wetlands are lacking hugely. The aim of this study was to develop a biological treatment technology that can be operated in an economic, reliable and robust mode over a long period of time. Two pilot-scale vertical-flow soil filter eco-technologies, a roughing filter (RF) and a polishing filter (PF) with plants (willows), were operated independently in a single-stage configuration and coupled together in a multi-stage (RF + PF) configuration to investigate the MTBE and benzene removal performances. Both filters were loaded with groundwater from a refinery site contaminated with MTBE and benzene as the main contaminants, with a mean concentration of 2970 ± 816 and 13,966 ± 1998 μg L−1, respectively. Four different hydraulic loading rates (HLRs) with a stepwise increment of 60, 120, 240 and 480 L m−2 d−1 were applied over a period of 388 days in the single-stage operation. At the highest HLR of 480 L m−2 d−1, the mean concentrations of MTBE and benzene were found to be 550 ± 133 and 65 ± 123 μg L−1 in the effluent of the RF. In the effluent of the PF system, respective mean MTBE and benzene concentrations of 49 ± 77 and 0.5 ± 0.2 μg L−1 were obtained, which were well below the relevant MTBE and benzene limit values of 200 and 1 μg L−1 for drinking water quality. But a dynamic fluctuation in the effluent MTBE concentration showed a lack of stability in regards to the increase in the measured values by nearly 10%, which were higher than the limit value. Therefore, both (RF + PF) filters were combined in a multi-stage configuration and the combined system proved to be more stable and effective with a highly efficient reduction of the MTBE and benzene concentrations in the effluent. Nearly 70% of MTBE and 98% of benzene were eliminated from the influent groundwater by the first vertical filter (RF) and the remaining amount was almost completely diminished (∼100% reduction) after passing through the second filter (PF), with a mean MTBE and benzene concentration of 5 ± 10 and 0.6 ± 0.2 μg L−1 in the final effluent. The emission rate of volatile organic compounds mass into the air from the systems was less than 1% of the inflow mass loading rate. The results obtained in this study not only demonstrate the feasibility of vertical-flow soil filter systems for treating groundwater contaminated with MTBE and benzene, but can also be considered a major step forward towards their application under full-scale conditions for commercial purposes in the oil and gas industries. 相似文献
8.
油基钻屑电磁加热脱附可行性及参数优化 总被引:1,自引:0,他引:1
油基钻屑含有大量的矿物油、乳化剂等化学药剂,成分复杂、处理困难,是页岩气等非常规油气开发的环保难题。为此,设计了一套油基钻屑电磁加热脱附处理设备,并进行了现场小试试验。通过检测电磁加热设备热脱附处理后的钻屑残渣含油率,分析试验过程中的温度变化规律,对设备处理油基钻屑的可行性进行了初步验证,并在此基础上优化了设备的主要运行参数:温度、负荷、时间。结果表明:1该电磁加热脱附处理设备对于油基钻屑具有良好的处理效果,处理后残渣含油率低于1%;2该设备适用范围广,可同时处理钻井过程中产生的编织袋、防渗塑料布等其他含油废物;3处理固控系统振动筛出渣(物料A)的最佳条件为温度375℃、进料负荷15 L/h、时间45 min;4处理固控系统离心机出渣(物料B)的最佳条件为温度350℃、进料负荷20 L/h、时间50 min;5电磁加热脱附炉内部温度的波动不受设定温度的影响,对不同负荷的物料也均能保证内部温度的稳定,具有稳定的控制温度能力和良好的保温效果。 相似文献
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The combustion characteristics of high-heating-rate chars from untreated and torrefied biomass fuels
Torrefaction of biomass is of great interest at the present time, because of its potential to upgrade biomass into a fuel with improved properties. This study considers the fundamentals of combustion of two biomass woods: short rotation willow coppice and eucalyptus and their torrefied counterparts. Chars were prepared from the untreated and torrefied woods in a drop tube furnace at 1100 °C. Fuels and chars were characterised for proximate, ultimate and surface areas. Thermogravimetric analysis was used to derive pyrolysis and char combustion kinetics for the untreated and treated fuels and their chars. It was found that the untreated fuels devolatilise faster than their torrefied counterparts. Similarly, the chars from the untreated biomass were also found to be more reactive than chars from torrefied fuels, when comparing reaction rates. However, the activation energy value (Ea) for combustion of the untreated eucalyptus char was higher than that for the torrefied eucalyptus chars. Moreover, the eucalyptus chars were more reactive than the willow char analogues, although they had seen a lower extent of burn off, which is also a parameter indicative of reactivity. Similar trends in were also observed from their intrinsic reactivities; i.e. chars from the untreated fuel were more reactive than chars from the torrefied fuel and eucalyptus chars were more reactive than willow chars. Chars were also studied using scanning electron microscopy with energy-dispersive X-ray analysis. This latter method enabled a semi-quantitative analysis of char potassium contents, which led to an estimation of potassium partitioning during char formation and burnout. Results show a good correlation between potassium release and percent burnout. With respect to the effect of torrefaction on fuel-N, findings suggest that torrefaction would be beneficial for pf combustion in terms of nitrogen emissions, as it resulted in lower fuel-N contents and ∼72–92% of the fuel-nitrogen was released with the volatile fraction upon devolatilisation at 1100 °C. 相似文献