淮北煤田煤中汞的赋存状态

系统采集淮北煤田10、7、5、4和3煤层的29个煤样品, 采用逐级化学提取方法研究了煤中汞的赋存状态, 根据提取步骤和汞的特性, 将煤中的汞分为水溶态、离子交换态、有机态、碳酸盐结合态、硅酸盐结合态和硫化物结合态, 利用Flow Injection Mercury System(FIMS)分析了样品中总汞和不同形态中汞的含量.测试结果表明, 与华北石炭-二叠纪煤、中国煤以及美国煤含量相比较, 淮北煤田煤中汞的含量明显富集.逐级化学提取实验结果和煤中汞与硫、灰分的相关分析结果表明, 岩浆的侵入对煤中汞的赋存状态有较大的影响, 不受岩浆侵入影响的10、4和3煤层煤中的汞主要以有机态和硫化物结合态存在, 受岩浆侵入影响的5和7煤层中的汞主要以硅酸盐结合态存在.      

柴北缘含煤区地层测井物性特征分析

以柴达木盆地北缘的鱼卡煤田为例,对含煤地层中的各种岩性的测井响应特征进行分析,认为该区的地球物理特征属＂简单易区别＂型,即煤岩层的物性差异较大,物性条件较好,不同岩性在伽马-伽马、自然伽马、电阻率等测井曲线上的特征明显,根据曲线的变化幅度、峰值高低等曲线特征,可有效进行煤岩层划分与对比。根据实际测井解释成果,对侏罗系上统红水沟组、采石岭组、侏罗系中-下统大煤沟组的页岩段、上含煤段及下含煤段等标志层段的测井曲线组合特征进行了描述。     

陕西黄陇煤田侏罗系煤层气开发关键技术

黄陵煤田侏罗纪煤层裂隙发育,渗透率高,煤层气开发的地质条件优越,即将成为我国煤层气开发一个重要的潜在接替领域,根据焦坪矿区和彬长矿区煤层气开发取得的成果,详细探讨了煤层气开发方式、井位部署、钻完井工艺、压裂工艺和排采工艺等关键技术,指出欠平衡钻进、基于储层保护的洞穴完井和分层控压联合排采将是该区煤层气开发技术发展的方向。     

利用地震属性预测煤层厚度及古河流冲刷带的方法

根据山西宁武煤田某煤矿2#煤层采掘及钻孔揭露情况,发现该井田中部和南部存在古河流冲刷带。通过对比基于优选的4个地震属性的四元一次、四元二次多项式回归模型与BP神经网络预测模型,决定将BP人工神经网络模型预测煤层厚度数据应用于整个测区古河流冲刷带的预判工作。首先利用GeoFrame系统和Landmark公司Poststack模块,提取2#煤层反射波的各类沿层切片,分析并圈定出2#煤层古河流冲刷带的大致范围,在此基础上,利用垂直时间剖面中2#煤层反射波的各种波形特征,进一步判别2#煤层古河流冲刷带解释的可靠性,然后结合BP神经网络预测模型获得的2#煤层厚度变化趋势图,最终解释出2#煤层古河流冲刷带范围:勘探区内2#煤层厚度变化范围0～5.3m,根据其煤层厚度变化趋势,将全区划分出一大二小3个古河流冲刷带。     

安徽巢湖煤田控矿构造雏论

采用现代构造几何分析方法,研究了巢湖煤田的控煤构造,发现巢湖煤田主要受大型平卧式褶皱逆冲推覆构造控制。按构造变形特点从南到北可以划分为和县-含山平卧式褶皱推覆构造、巢湖银屏山平卧式褶皱推覆构造和无为平卧式褶皱推覆构造 3个构造带,卷入了震旦系灯影组-三叠系的整个扬子海相沉积盖层。这种大规模的褶皱逆冲推覆是扬子板块沿着郯庐断裂向华北板块A型俯冲的产物。      

叠前时间偏移方法在煤田勘探中的应用

根据克希霍夫积分法的原理,介绍了叠前时间偏移的方法特点,实现过程,以及对地震资料的要求,依托国家重大产业技术专项“西部煤炭资源高精度三维地震勘探”工程,对“青海省鱼卡煤田四井田高精度三维地震勘探”资料进行叠前时间偏移,结果表明其能较好地解决成像质量差、能量聚焦不明显、绕射波收敛不理想等方面的难题。通过与叠后时间偏移对比,对于大倾角地层、断块小且多的破碎带、陡倾角不对称向斜等地质问题,其叠前时间偏移剖面成像质量都有明显的提高,反映的构造关系更加清晰,同相轴连续性增强。总结该方法在多个矿区的推广经验．认为合理的观测系统、较高的资料信噪比,准确的测量资料及较高的中表层速度调查精度是做好叠前时间偏移的前提。     

Geochemistry of environmentally sensitive trace elements in Permian coals from the Huainan coalfield, Anhui, China

To study the geochemical characteristics of 11 environmentally sensitive trace elements in the coals of the Permian Period from the Huainan coalfield, Anhui province, China, borehole samples of 336 coals, two partings, and four roof and floor mudstones were collected from mineable coal seams. Major elements and selected trace elements were determined by inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), and hydride generation atomic absorption spectrometry (HAAS). The depositional environment, abundances, distribution, and modes of occurrence of trace elements were investigated. Results show that clay and carbonate minerals are the principal inorganic constituents in the coals. A lower deltaic plain, where fluvial channel systems developed successively, was the likely depositional environment of the Permian coals in the Huainan coalfield. All major elements have wider variation ranges than those of Chinese coals except for Mg and Fe. The contents of Cr, Co, Ni, and Se are higher than their averages for Chinese coals and world coals. Vertical variations of trace elements in different formations are not significant except for B and Ba. Certain roof and partings are distinctly higher in trace elements than underlying coal bench samples. The modes of occurrence of trace elements vary in different coal seams as a result of different coal-forming environments. Vanadium, Cr, and Th are associated with aluminosilicate minerals, Ba with carbonate minerals, and Cu, Zn, As, Se, and Pb mainly with sulfide minerals.     

Key Groundwater Control Factors of Deep Buried Coalfield by Landform and Sedimentation in the Northern Ordos Basin

There were three landforms (i.e. desert, bedrock platform and loess gully) in deep-buried coalfield of northern Ordos Basin. Water inflow of working face in desert area was 1~2 orders of magnitude larger than that in other landform areas. In order to find out the key controlling factors of the directly water filled aquifers on the roof of the coal seam, we carried out research from the aspects of topography, landform and geological sedimentation. The results showed that desert landform provides abundant recharge water for underlying aquifers because of gentle topography, large precipitation infiltration coefficient, thick and water-rich quaternary system. While bedrock platform and loess gully landform were the water sources with weak recharge capacity of underlying aquifers. The sandstone-mudstone interbedding structure formed by continental deposits resulted in the absence of regional stable aquifers in Jurassic and Cretaceous strata on the roof of coal seams. Pumping tests of boreholes showed that all strata belong to weak to medium water-rich aquifers. The groundwater level of Cretaceous aquifer decreased by 20~130 m in three mines. There was a close hydraulic relationship between shallow and deep aquifers. The Mesozoic strata belonged to fluvial deposits. Qilizhen sandstone and Zhenwudong sandstone aquifers were mainly developed on the roof of the coal seam, which were characterized by thick medium-coarse sandstone sections. The geological and sedimentary conditions of direct water-filled aquifer were similar, but the amount of borehole water, cumulative pre-drainage water and water inflow from goaf in desert geomorphic area were much larger than those in bedrock platform and loess gully geomorphic area. The water-rich of the aquifer was mainly controlled by geomorphology, and the water sources of the deep aquifers were meteoric precipitation and Quaternary aquifer. In different mines with similar Quaternary conditions in Mu Us Desert, there were also great differences in the amount of borehole water, cumulative pre-drainage water and water inflow from goafs. The difference was related to the thickness and lithology of the aquifers. It reflected that the geological sedimentary conditions of the coal seam roof were also important factors to control the water-rich of the aquifers. Topography, landform and geological sedimentation were the key factors to control the water-rich of the aquifer directly and the water inflow from the working face.     

利用XRD法探讨邢台隆东井田煤变质规律

邢台隆东井田煤变质情况复杂,直接影响煤的工业利用。利用X-射线衍射(XRD)法探讨了区内不同变质程度煤的基本结构单元特征及煤变质规律。结果显示:垂向上,随着煤层埋藏深度的增加,层片间距d₀₀₂值逐渐减小,层片堆积高度L_c和层片直径L_a值逐渐增大;平面上,离岩浆侵入体越近,煤层的层间距d₀₀₂值越小,反之d₀₀₂值越大。在煤种分布上,因受岩浆热源的影响,井田内煤种以旧城为中心向外呈带状分布,旧城附近为无烟煤,向外逐渐过渡为贫煤、瘦煤、焦煤、肥煤和气煤。区内煤变质作用主要受区域变质作用影响,并叠加了岩浆热变质作用。      

合山煤田矿井水害防治措施探讨

合山煤田是典型的岩溶充水矿床．矿井开采水害严重。煤层的直接顶、底板为碳酸盐岩类,岩溶极为发育,为矿井的直接充水含水层;煤层底部的茅口组为强岩溶含水层,与煤系地层的联系密切,为间接充水含水层;位于煤田两侧的红河水是矿井充水最主要的补给水源。断裂、节理和破碎带等通道是矿井充水的主要通道。通过分析井下突水点的发育特征,认为强岩溶导水带是矿井突水的关键部位,防治矿井水害的重点是切断岩溶导水带,对强导水带进行封堵,防止红水河的侧向补给,对四煤底板灰岩进行加固。总结出地面防治的主要方法为帷幕式、截堵式、堵水点式和地面铺盖式。对井下防治水,提出了有疑必探,先探后掘,设置防水闸门、防水墙,实行分层、分区开采,加强井下排水等防治措施。