煤矿工业场地道路照明接地系统问题探讨

文章简要介绍了煤矿工业场地的特点和低压配电系统接地方式分类,从安全性、经济性的角度分析了TN接地系统和TT接地系统在道路照明回路中的优缺点。通过对比TN-S系统与TT系统的接地故障电流差异、TN-S接地系统用于道路照明的等电位联结困难程度,总结出煤矿工业场地的道路照明配电系统适宜采用TT接地方式。并且详细阐述了TT接地系统剩余电流动作保护器保护整定方法和灵敏度校验方法,列举了煤矿工业场地道路照明选用TT系统时需要注意的中性线不可重复接地的问题。     

厚煤层放顶煤大角度扇形收尾施工工艺实践

以左云长春兴煤业公司301综放工作面扇形收尾施工工艺为背景,介绍了在工作面受地质构造或者井田边界影响,工作面两顺槽与盘区大巷斜交布置时,为了多回收煤炭资源,提高经济效益,采取大角度扇形收尾的施工工艺,为厚煤层放顶煤大角度扇形收尾提供了借鉴和理论依据。     

PETROLEUM POTENTIAL, THERMAL MATURITY AND THE OIL WINDOW OF OIL SHALES AND COALS IN CENOZOIC RIFT BASINS, CENTRAL AND NORTHERN THAILAND

Oil shales and coals occur in Cenozoic rift basins in central and northern Thailand. Thermally immature outcrops of these rocks may constitute analogues for source rocks which have generated oil in several of these rift basins. A total of 56 oil shale and coal samples were collected from eight different basins and analysed in detail in this study. The samples were analysed for their content of total organic carbon (TOC) and elemental composition. Source rock quality was determined by Rock‐Eval pyrolysis. Reflected light microscopy was used to analyse the organic matter (maceral) composition of the rocks, and the thermal maturity was determined by vitrinite reflectance (VR) measurements. In addition to the 56 samples, VR measurements were carried out in three wells from two oil‐producing basins and VR gradients were constructed. Rock‐Eval screening data from one of the wells is also presented. The oil shales were deposited in freshwater (to brackish) lakes with a high preservation potential (TOC contents up to 44.18 wt%). They contain abundant lamalginite and principally algal‐derived fluorescing amorphous organic matter followed by liptodetrinite and telalginite (Botryococcus‐type). Huminite may be present in subordinate amounts. The coals are completely dominated by huminite and were formed in freshwater mires. VR values from 0.38 to 0.47%R_o show that the exposed coals are thermally immature. VR values from the associated oil shales are suppressed by 0.11 to 0.28%R_o. The oil shales have H/C ratios >1.43, and Hydrogen Index (HI) values are generally >400 mg HC/g TOC and may reach 704 mg HC/ gTOC. In general, the coals have H/C ratios between about 0.80 and 0.90, and the HI values vary considerably from approximately 50 to 300 mg HC/gTOC. The HI_max of the coals, which represent the true source rock potential, range from ～160 to 310 mg HC/g TOC indicating a potential for oil/gas and oil generation. The steep VR curves from the oil‐producing basins reflect high geothermal gradients of ～62°C/km and ～92°C/km. The depth to the top oil window for the oil shales at a VR of ～0.70%R_o is determined to be between ～1100 m and 1800 m depending on the geothermal gradient. The kerogen composition of the oil shales and the high geothermal gradients result in narrow oil windows, possibly spanning only ～300 to 400 m in the warmest basins. The effective oil window of the coals is estimated to start from ～0.82 to 0.98%R_o and burial depths of ～1300 to 1400 m (～92°C/km) and ～2100 to 2300 m (～62°C/km) are necessary for efficient oil expulsion to occur.     

双河油田注入水适应性及注水井酸化解堵研究

考察了双河油田双河联、江河联注入水堵塞地层的因素;膨胀性黏土，悬浮固体颗粒。细菌及悬浮污油。含膨胀性黏土的双河南、双河北及不含膨胀性黏土的双江岩心粉，在注入水中相对于地层水中的体积膨胀度分别为14．5％、11．1％及0．02％；注入100PV不含悬浮颗粒的等体积比地层水、注入水混合水使双河、双江岩心渗透率分别下降7％和4％、9％和7％。注入水中悬浮颗粒引起岩心渗透率下降，粒径越大、颗粒浓度越大、注入量越大，则渗透率越低。在粒径2．1μm或颗粒浓度3mg／L前后下降幅度变化较大。注入水中硫酸盐还原菌引起岩心渗透率下降，含菌量越大则渗透率开始下降时的注水量越小，注入含菌50个／L的水100PV使岩心渗透率下降7％。岩心对注水合油量敏感，注入含油量20mg／L的水50PV使岩心渗透率下降20％。在岩心注水实验中渗透率下降最严重的是双河南岩心，其次是双河北岩心．江河岩心较轻，注入精细过滤水的双河北岩心渗透率下降大大减少．说明悬浮固体是造成注水堵塞的主要因素。为了解除双河油田注水井的堵塞，研制了含黏土稳定剂、缓蚀剂、铁离子稳定剂、互溶剂的土酸液，与南阳油田使用的低伤害酸液一起，用于1口注水井的解堵，效果良好。图7表4参5。     

乐滩灌区输水隧洞穿合山煤矿采空区处理设计

分析了乐滩灌区工程北干渠溯河隧洞段长约1.06 km穿合山煤矿采空区的地质情况.借鉴高速公路煤矿采空区的成功处理经验,通过科学分析,对采空区变形和区域内覆岩的稳定性做了评价,论述了输水线路穿采空区段采取全充填压力注浆法的工程处理方法.     

露天转地下联合开采技术探讨

针对复杂型锰矿开采提出了由露天转地下联合开采技术，与其它采矿方法相比较，这种方法提高了回采率，降低了采矿成本。     

Inhibition of microbial growth in ready‐to‐eat food stored at ambient temperature by modified atmosphere packaging

This study was undertaken to develop a modified atmosphere package to control microbial growth in ready‐to‐eat (RTE) products stored at ambient temperature. Ethanol and/or limonene associated with modified atmosphere (CO₂ : O₂ : N₂ = 30% : 5% : 65%) was used to inhibit the growth of total air‐borne microorganisms and Escherichia coli in RTE products stored at 25°C. The results indicated that 0.05% ethanol vapour in the headspace was effective to inhibit the growth of air‐borne microorganisms and E. coli at 25°C for 72 h in a model study, and the effectiveness was related to ethanol content. Both 73 ppm limonene and 0.05% ethanol vapour enhanced the bacteriostatic effect of modified atmosphere in RTE sushi roll products, and no off‐flavour was detected using this formulated gas; however, no significant inhibitory effect was observed for RTE cold noodle products. This study concludes that combinations of carbon dioxide, ethanol or limonene vapours are effective to inhibit microbial growth in RTE food at ambient temperature, and the outcome may be due to the hurdle effect. Copyright © 2003 John Wiley & Sons, Ltd.     

大庆长垣以东地区深层天然气输导特征及成藏

大庆长垣以东地区深层天然气输导通道主要由断裂、不整合面和砂体构成。该区砂体横向分布不稳定，物性差，不是天然气侧向长距离运移的输导通道，但可以起到衔接输导作用。输导通道时该区天然气成藏与分布起到了重要控制作用，主要表现在断裂将天然气输导致上覆不同储集层中聚集成藏。不整合面和砂体将天然气输导到四周古隆起上聚集成藏。沿断裂输导的天然气形成以断层为主的构造气藏。沿不整合面和砂体输导的天然气形成以地层及岩性为主的气藏。沿断裂输导运移聚集的天然气在剖面上呈串多层分布，沿不整合面和砂体输导运移聚集的天然气在平面上呈环状分布。     

自制煤层气井排采试气流程

根据煤层气井排采试气特点，调研目前各公司煤层气井排采流程的使用情况，结合武MXX多分支水平井产水量高、产气量高的要求，自制一套煤层气排采试气流程，满足大部分井的排采需要。     

人工神经网络预测煤的发热量

应用人工神经网络处理部分广东地区煤质分析数据,建立网络模型,预测出煤的发热量,经实测值与预测值比较,在一定的煤种范围内预测值与实测值比较接近。