Factors Influencing Proppant Transportation and Hydraulic Fracture Conductivity in Deep Coal Methane Reservoirs

The gas production of deep coalbed methane wells in Linxing-Shenfu block decreases rapidly,the water output is high,the supporting effect is poor,the effective supporting fracture size is limited,and the migration mechanism of proppant in deep coal reservoir is not clear at present.To investigate the migration behavior of proppants in complex fractures during the volume reconstruction of deep coal and rock reservoirs,an optimization test on the conductivity of low-density proppants and simulations of proppant migration in complex fractures of deep coal reservoirs were conducted.The study systematically analyzed the impact of various fracture geometries,proppant types and fracturingfluid viscosities on proppant distribution.Furthermore,the study compared the outcomes of dynamic proppant transport experiments with simulation results.The results show that the numerical simulation is consistent with the results of the proppant dynamic sand-carrying experiment.Under the conditions of low viscosity and large pumping-rate,a high ratio of 40/70 mesh proppant can facilitate the movement of the proppant to the depths of fractures at all levels.The technical goal is to create comprehensive fracture support within intricate trapezoidal fractures in deep coal and rock reservoirs without inducing sand plugging.The sand ratio is controlled at 15%–20%,with a proppant combination ratio of 40/70:30/50:20/40=6:3:1.Proppant pumping operations can effectively address the issue of poor support in complex fractures in deep coal formations.The research results have been successfully applied to the development of deep coalbed methane in the Linxing-Shenfu block,Ordos Basin.

A comparison of the energy consumption and carbon emissions for different modes of transportation in open-cut coal mines

Transportation accounts for 80% of open-cut coal mine carbon emissions. With regard to the energy con- sumption and carbon emissions of transportation within an open-cut mine, this paper systematically compared the work and energy consumption of a truck and belt conveyor on a theoretical basis, and con- structed a model to calculate the energy consumption of open-cut mine transportation. Life cycle carbon emission factors and power consumption calculation model were established through a Process Analysis- Life Cycle Analysis （PA-LCA）. The following results were obtained： （1） the energy consumption of truck transportation was four to twelve times higher than that of the belt conveyor; （2） the C02 emissions from truck transportation were three to ten times higher than those of the belt conveyor; （3） with the increase in the slope angle for transportation, the ratio of truck to belt conveyor for both energy consumption and carbon emissions gradually decreased; （4） based on 2013 prices in China, the energy cost of transportation using a belt conveyor in open-cut coal mines could save 0.6-2.4 Yuan/（t kin） compared to truck transportation.

Study on characteristics of pipeline transportation and sulfur fixing of cleaned coal logs

As special cylindrical briquettes of coal for long distance pipeline transportation and directly cleaned combustion the cleaned coal logs should possess two characteristics of transportation in pipeline and cleaned combustion. In order to make cleaned coal logs a rational technology for manufacturing, cleaned coal logs was designed and compound sulfur fixing binders with high effects of binding and sulfur-fixing was selected and combined. In addition, by means of characteristic experiments of strength, wear, waterproof and sulfur-fixing five different cleaned coal logs made with different compound sulfur fixing binders in different compaction conditions was tested and measured. Experimental results indicated that the manufacturing technology of cleaned coal logs was reasonable and the combination of compound sulfur fixing binders was scientific. Cleaned coal logs made up with the fourth group of coal mixture had high strength, good waterproof property, efficient sulfur-fixing, good characteristic of transportation, and achieved the performance requirement for pipeline transportation and sulfur fixing.

Research on management of coal bed methane warehousing and transportation based on GIS

At present Coal Bed Methane （CBM） has become the important part of clean energy in China. and will optimize the energy structure in China unceasingly. However, warehousing and transportation of CBM become one of the core factors that restrain its exploitation and utilization at present, due to the space-time character of natural deposit and modem utilization of CBM. In this paper, according to the character of CBM and the expanding trend of its utilization, the necessity of constructing the CBM＇s warehousing and transportation management system demonstrated. Index system that influence CBM＇s warehousing and transportation is established. And CBM＇s warehousing and transportation model is established by Voronoi diagram. In light of above research, CBM＇s warehousing and transportation management system based on Geography Information System （GIS） is designed, Using this system, CBM＇s warehousing and allocation center in one mining area is optimized. Research shows that to reinforce CBM＇s warehousing and transportation management is one of the key factors for coordinating the development of its development and utilization, thereby ensuring its sustainable development and utilization.

Application of open-pit and underground mining technology for residual coal of end slopes

Given the conditions of residual coal from the boundary of a flat dipping open-pit mine,which uses strip areas mining and inner dumping with slope-covering,we propose an open-pit and underground integrated mining technology for residual coal of end slopes.In the proposal a conveyance road and ventilation conveyance near the slope are built,corresponding to the pit mining area and the surface coal mine dump,as well as an interval haulage tunnel and air-inlet tunnel.The outcome shows that such mining method may reduce the effect to slope stability from underground mining,it does not affect the dumping advance and has a high recovery rate of residual coal resources.The working face is timbered by single hydraulic props,transported by a scraper conveyor and supported by coal walls.This method of mining is one of layered top coal caving,with high resource recovery,low production cost where positive economic benefit can be realized.

Thermal recovery process of a backfilled open-pit in permafrost area at the Gulian strip coal mine in Northeast China

Timely and proper backfilling of open-pits in strip coal-mines has been an effective measurement for the recovery of the hydrothermal regimes and ecological environment in permafrost regions. In this study, numerical simulations and statistical regressions were applied for analyzing the recovery processes of the backfill and its major influencing factors for the thermal equilibrium in recently backfilled open pits at the Gulian strip coalmine in Mo'he, Northeast China. Results show that the thermal recovery time of backfilled areas is positively correlated to the backfill depth(BD) of the soils, the backfilled soil temperature(BST), and the mean annual ground surface temperature(MAGST); meanwhile, climate warming can impact on thermal regimes of the backfill area. The impact of climate warming on ground temperature of the backfill will show up significantly in about 50 years afterbackfilling(BD at 10.0 and 20.0 m, BST at 20.0°C) under the climate warming scenario(CWS) of 0.025°C·year ^(-1). Grey-relation analyses show that the sensitivity of the backfill recovery time declines in the order of the BD, BST and MAGST. On the basis of the abovementioned studies, the layer-by-layer backfilling in cold seasons is advised for more effective and more rapid recovery of thermal regimes of the backfilled open-pits in cold regions.

Advanced Strategies to Mobilize Crop Residue to Replace Coal in India

Various published data show the amount of crop residue available annually in India may range from a low of 90 to a high of 180 million tonnes. Different types of crop residue are collected from farmers depending on the geography and crop pattern for instance, in north India rice straw and cotton stalks are collected while in central India soya husk and sugarcane tops are collected. Baling and transporting straw from the field, though appear to be an option for safe disposal, will be feasible only when alternate, effective and economically viable usage methods are identified and facilities and infrastructure for ex-situ management methods are created. One immediate short term use of the residue is to replace 5% - 7% of the 670 million tonnes of coal India currently consumes to generate power. The farmers will benefit from the sale of their excess crop residue. The scheme will reduce pollution due to residue burning practices. Replacing coal will cut the GHG emissions. The challenge is to mobilize the crop residue collection and timely delivery to power plants. The data and calculations in this monogram show that it is economical for the farmer to remove the crop residue from the field quickly by using modern balers, to pelletize the biomass in small-scale distributed pellet plants, to store pellets in the modern steel bins and finally to deliver the pellets to coal plants by using rail transport. The delivered cost is estimated at around Rp 6.78/kg. The Government of India encourages the power plants to pay at least Rp 10/kg for the delivered biomass in the form of pellets. The current monogram analyzes the organization of an efficient supply chain in the State of Haryana India to ensure a sustainable modern enterprise.

基于语义分割的带式输送机煤料运输区域检测算法

针对煤炭运输过程中,经常无法保持煤炭在带式输送机上的运量均匀,使得带式输送机长时间全速运转而造成电能浪费和设备无效磨损的问题,提出一种基于语义分割的带式输送机煤料运输区域检测算法。该算法在DeeplabV3+的基础上,根据特征通道之间的相互依赖关系,引入注意力机制,使用不同扩张率的卷积核获得多种尺度的语义信息,来精确分割出煤炭在带式输送机的运输区域。实验结果表明,该算法平均交并比(Mean Intersection over Union,MIoU)相比于DeeplabV3+算法提高1.24百分点,能够有效精准地分割出煤料的运输区域,为煤量估计工作提供有效的保障。

西北干旱露天煤矿排土场土壤重构与水盐运移机制

矿山排土场生态修复是煤矿露天开采面临的重大环境问题,是制约建设绿色露天煤矿的重要因素。土壤重构是排土场生态修复的重要步骤,以新疆为代表的西北煤炭基地,水资源短缺,盐碱化突出,土壤水盐运移是决定土壤重构是否成功的关键指标。目前研究集中在表层土壤重构改善土壤养分促进植物生长,针对保水控盐的功能化土壤重构的研究甚少,对不同土壤重构方式下的水盐运移机制尚不明晰。研究立足新疆煤炭资源禀赋特征,从煤炭循环经济的角度出发,采用能源化工副产物煤气化渣(CGS)作为重构材料,通过毛细水上升-蒸发试验,分析CGS重构后水盐垂向运移和水分供给能力,通过Van Genuchten模型拟合土壤水分特征曲线,分析CGS重构后土壤持水能力,研究CGS作为含水层重构材料的可行性。采用煤矿开采伴生岩石矿物红泥岩作为重构材料,通过土柱入渗蒸发试验,分析红泥岩重构后不同土壤深度的水盐变化情况,研究泥岩作为隔水层重构材料的可行性。结果表明,CGS重构改善土壤质地,优化孔隙结构,促进了土壤水盐运移,毛细作用增强,促进了下层水分向上供给,同时也增加了盐分表聚,重构改变土水特征曲线参数,增加了饱和含水量θ_(s),降低了参数a和n,改善了土壤持水性能。CGS添加量越高,细渣质量分数越大,效果越明显。CGS作为重构含水层材料具有可行性。红泥岩黏粒和次生矿物含量高,孔隙结构丰富,物理吸附性良好,重构后0~24 cm深度下土壤含水率高于对照组,蒸发后的盐分在20~24 cm达最高值,红泥岩有效阻隔了盐分上移。红泥岩作为重构隔水层材料具有可行性。研究以期探索出一条适合西部煤炭基地排土场土壤重构模式。

融合麻雀搜索与长短时记忆的疆煤铁路外运量预测

为准确预测新疆煤炭铁路外运量,本文提出一种融合麻雀搜索算法与长短时记忆网络的(SSA-LSTM)预测模型,模型引入麻雀搜索算法对长短时记忆网络(Long Short-Term Memory,LSTM)模型的超参数进行优化,以提高模型预测性能。以2015—2022年新疆煤炭铁路外运量数据为基础,综合考虑经济、运输等多种因素,对各影响因素的灰色关联度进行计算,验证所选因素与预测指标具有较强的关联度。对影响因素中的GDP数据进行消费者价格指数(Consumer Price Index, CPI)处理,并将处理后的数据输入模型进行预测,最后应用该模型对未来新疆煤炭初、近、远期铁路外运量进行预测。研究结果表明,SSA-LSTM模型的预测效果显著优于BP(Back Propagation)神经网络和传统LSTM模型,平均绝对百分比误差(MAPE)为0.88%,均方根误差(RMSE)为49.9。同时,与未经CPI处理的预测相比,经过CPI处理后预测误差更小,MAPE和RMSE分别降低了75.8%和56.2%。本文为新疆煤炭铁路外运量预测提供了一种有效方法,为疆煤外运通道设计提供了重要数据支撑。

小保当一号煤矿特大型智能主运输系统设计

针对小保当煤矿主运输系统大运量、高带速、高带强的特点,进行了技术方案的分析研究并对各部带式输送机均采用了最佳配置设计。文章介绍了采用多项国内外先进技术对主运输系统的各个具体环节进行的优化设计,包括:采用智能化设计技术,实现主运输系统的远程集中控制、协同运行和无人值守;采用特大型装备设计技术,对系统关键位置及重要部件进行分析研究,确保安全;采用井下煤水分离技术,对原煤进行脱水处理,避免“水煤”隐患;采用动力学分析技术,对多种不利工况下的输送带张力特性进行模拟,优化设备布置。最终实现了国内井下总运输距离最长、装机总容量最大的煤炭主运输系统的智能化、无人化长期连续平稳运行,为国内特大型矿井的煤炭主运输系统设计起到了引领示范作用。

关于打通铁路网运输能力堵点对策探究

国铁企业落实党中央部署要求并加快推进铁路货运市场化改革,采取有效措施尽快打通铁路网运输能力堵点,有效降低物流成本。通过分析路网总体规模、旅客运输供给能力、货物运输保障能力等铁路网运输能力现状,剖析铁路网运输能力堵点及成因。在此基础上,提出加强铁路网运输能力经验借鉴,探析打通铁路网运输能力堵点对策,即:畅通普速干线通道,加强煤运通道能力保障,强化中欧班列通道能力,完善港口铁路通过能力,增强西部陆海新通道线路能力,完善枢纽点线配套能力,强化铁路货运设施设备卸车能力等方面,在助力降低全社会物流成本中发挥“火车头”的重要作用。

提升神东采掘运设备价值最大化的措施

通过调研和分析神东公司采掘运大型机电设备目前的使用和管理现状,从神东集团13个矿井的生产、机电设备结构配置、机电设备成本、机电设备管理等方面入手,深入分析影响采掘运大型机电设备价值最大化的原因,并给出后期发挥采掘运大型机电设备最大使用价值的努力方向,对降低机电设备成本的投入以及安全、高效生产具有现实意义,对其他煤炭企业采掘运设备的高效、精细、精益、价值最大化管理亦有重要的借鉴作用。

鞣花酸对下石节长焰煤氧化自燃的阻化影响研究

为考察鞣花酸(EA)对煤氧化自燃过程的影响,首先将EA与陕西铜川下石节煤矿的长焰煤以2%、4%、6%、8%和10%的质量比均匀混合进行试验;然后采用显微红外光谱试验和激光导热试验研究各个样品的活性官能团含量情况和热输运特性,通过评价煤氧化自燃抑制效果,确定最优质量比为8%;最后利用煤自燃程序升温试验对比4种阻化剂对煤氧化自燃气体释放的影响情况,进一步确定EA对煤氧化自燃的阻化程度。结果表明:EA处理煤(EA-tc)中-CH_(3)、-CH_(2)、-OH和-C=O-的峰面积相较于原煤(RC)均减少,但C-O的峰面积增加;在相同煤温下,RC的热扩散系数和导热系数高于EA-tc,其比热容低于EA-tc,且8%EA对RC低温氧化过程的热扩散系数、比热容和导热系数的平均抑制率分别为20.8%、9.8%和13.1%;相比于RC,8%EA-tc的CO释放量在170℃时降低52.3%,且EA对煤氧化自燃的阻化率在30~170℃内保持在50.5%~72.5%,说明EA对煤氧化自燃的阻化效果比其他3种阻化剂更好。

基于LEAP模型的煤炭综合运输能耗与碳排放研究

为全面掌握大型煤炭运输企业碳排放现状及发展趋势,识别高能耗排放重点环节,基于传统LEAP方法,构建了企业层面的能源需求与环境影响发展模型,以模拟不同减排方案的减排效果。模型包含运输环节、运输内部作业、能源类型、温室气体种类4层结构,以运输工作量为推动因子,同时考虑运输企业经营范围内的辅助生产排放与电力、热力隐含排放。采用情景分析法,设置了新能源交通两网融合、新能源装备、能效提升、排放控制以及负碳生态情景共5个技术政策情景,通过与基准情景对比,对比分析不同技术政策影响下煤炭铁水联运企业的能源消费与碳减排效果。研究发现,其中4个情景可以实现2030年碳达峰,而单一技术政策情景均不能如期实现碳中和,需采取综合措施。

新疆煤炭产业发展现状及疆煤外运经济性分析研究

针对新疆煤炭外运经济性差的问题,基于近几年我国煤炭供需形势的新变化和新疆煤炭产业发展现状,分析了未来疆煤出区的主要目标市场煤炭需求量,梳理了新疆哈密和准东煤炭主产区至各目标市场的运距运费及市场价对比情况,重点研究了疆煤运至不同区域的经济性。研究表明:近三年内哈密和准东地区煤炭市场价一直处于低位,与其外运目标市场均存在一定的价格差,且在疆煤市场价与各外运目标省份及黄骅港保持一定差值时,煤炭出疆具备一定经济性。

煤矿运输复合降尘剂的制备与降尘性能研究

为了降低煤炭资源运输过程中粉尘的污染程度,以烷基糖苷、3-氯-2-羟丙基三甲基氯化铵和助剂A为主要原料,制备了一种适合煤矿运输用的新型复合降尘剂JCS-1,以除尘效率为评价指标对其制备条件进行了优化,并考察了不同质量分数复合降尘剂JCS-1的表面活性、润湿性能和降尘性能。实验结果表明:在反应温度为85℃、反应时间为5 h、助剂A的质量分数为5%的条件下制备的复合降尘剂JCS-1的除尘效率最高;随着复合降尘剂JCS-1质量分数的不断增大,溶液表面张力和其在煤薄片表面的接触角均呈现出逐渐降低的趋势,而除尘效率则呈现出先增大后减小的趋势;当复合降尘剂JCS-1的质量分数为0.05%时,除尘效率可以达到最大(96.6%),降尘效果较好,能够满足煤矿运输过程中降尘作业的需求。

新型自动化插爪制动牵引车的设计

为解决无极绳牵引车断绳制动不可靠的问题,自主研制了新型自动化插爪制动牵引车,该牵引车主要是由车体框架、插爪制动装置、弹簧滑轮组件等部分组成,当钢丝绳松绳量达到1000 mm时,插爪自动插住枕木实现断绳自动制动的功能,解决了无极绳牵引车在变坡点瞬时超速於绳而产生的插爪误动作以及跑车时插爪不动作的技术问题。同时,设计了新型自动化插爪制动牵引车的放车试验方案,试验结果表明:车身制动平稳,插爪安全可靠,达到了设计预期。新型插爪制动牵引车的研制拓宽了无极绳牵引车的使用范围,为无极绳卡轨车的安全运行提供了保障。

晋煤外运铁路运输增量对策探讨

山西省煤炭资源丰富,一直以来都是国家能源中心,其外运煤炭有力地保障了华北、东北、华东、华中等地区的能源需求,但目前受制于铁路运输能力的限制,晋煤外运能力还有待进一步提高。通过阐述晋煤外运现状和铁路外运北部、中部、南部3大通道,提出目前晋煤外运铁路运输过程中存在的空敞车运用紧张、分界口利用率不高、主要通道能力饱和、南北车流交换不畅、点线能力不匹配等运输瓶颈,并针对性地提出通过强化外铁路局集团公司排空力度、提高分界口利用率、优化车流组织结构、加强南北车流组织、提高编组站作业能力等优化对策,以提升铁路外运能力,实现山西地区煤炭外运目标,满足外运市场煤炭需求。

提高临哈铁路货运能力对策研究

临哈铁路作为疆煤外运的北翼通道,提高其货运能力,为国家能源安全稳定供应提供运力支撑,对进一步服务国家能源保供大局具有十分重要的意义。在阐述临哈铁路基本情况及货运需求能力分析的基础上,针对临哈铁路运输组织过程中存在的单线区段限制能力提升、大区间列车运行调整困难、点线能力不协调不匹配、衔接线路通道能力紧张、分界口利用率不高、机车运用紧张、机班投入不足等问题分析原因,有针对性地提出新增二线及电化工程改造、开通部分车站侧线、修建车站增加会车能力、优化临河节点运输组织、加强外排车流输送、组织均衡运输及优化机车机班运用等建议,以期达到提高临哈铁路货运能力的目的。