Production Characteristics and the Control Factors of Surface Wells for Relieved Methane Drainage in the Huainan Mining Area

Based on the production data of a large number of surface drainage wells in the Huainan mining area,the present study shows that four types of typical production characteristics for relieved methane wells are recognized,of which the stable type for production and gas concentration is the most dominate,as determined by a comprehensive study on the volume and concentration of drained gases, as well as the stress changes of rocks influenced by mining.Some influence factors for the productive differences of the drainage wells were also been discussed.The results indicate that protective coal-seam mining has a significant effect on overlying strata,which promotes the development of pores and fractures of coal reservoirs for methane desorption and migration;however,the production and the stability of drainage wells are affected by deformation and damage of the overlying strata.The second distribution of strata stress is caused by mining engineering,and if the stress load is larger than the carrying capacity of the extraction well,the gas production would be influenced by the drainage well that has been damaged by rock movement.Furthermore,the case damage occurs first in the weak, lithologic interface by its special mechanical properties.The stability of drainage wells and the production status are also influenced by the different drilling techniques,uneven distribution of gas concentration,and combination of gob gas and methane from the protected layer.

Exploitation technology of pressure relief coalbed methane in vertical surface wells in the Huainan coal mining area

Exploitation technology of pressure relief coalbed methane in vertical surface wells is a new method for exploration of gas and coalbed methane exploitation in mining areas with high concentrations of gas, where tectonic coal developed. Studies on vertical surface well technology in the Huainan Coal Mining area play a role in demonstration in the use of clean, new energy resources, preventing and reducing coal mine gas accidents and protecting the environment. Based on the practice of gas drainage engineering of pressure relief coalbed methane in vertical surface wells and combined with relative geological and exploration en- gineering theories, the design principles of design and structure of wells of pressure relief coalbed methane in vertical surface wells are studied. The effects of extraction and their causes are discussed and the impact of geological conditions on gas production of the vertical surface wells are analyzed. The results indicate that in mining areas with high concentrations of gas, where tectonic coal developed, a success rate of pressure relief coalbed methane in surface vertical well is high and single well production usually great. But deformation due to coal exploitation could damage boreholes and cause breaks in the connection between aquifers and bore-holes, which could induce a decrease, even a complete halt in gas production of a single well. The design of well site location and wellbore configuration are the key for technology. The development of the geological conditions for coalbed methane have a significant effect on gas production of coalbed methane wells.

Technology of gas drainage and utilization in Huaibei mining area

With the characteristics of coal seam geology and gas occurrence,a'ground-underground' integrated gas drainage method was formed,which can relieve gaspressure and increase permeability by mining the protection seams in conditional regions.After coal seam gas drainage,high gas outburst seam was converted to low gas safetyseam.In the coal face mining process,safety and high efficient coal mining were realizedby the measure of gas-suction over mining.In addition to the drainage gas for civil gasand gas power generation,the Huaibei Mining Group has actively carried out research onthe utilization technology of methane drainage by ventilation.On the one hand,it can saveprecious energy;on the other hand,it can protect the environment for people's survival.In2007,the amount of coal mine gas drainage was 120 hm3;the rate of coal mine gasdrainage was 44%.Compared with the year 2002,the amount of coal mine gas drainageincreased by two times.Meanwhile,the utilization rate of gas increased rapidly.

Failure characteristics of surface vertical wells for relieved coal gas and their influencing factors in Huainan mining area

从通过洞基于数据并且记载，我们在 Huainan 采矿区域和它的影响因素为减轻的煤气体学习了表面排水井的失败特征。结果证明排水井的损坏位置主要在西方采矿区域在基岩的上面的节在厚泥土层位于低冲积层和 lithological 接口。casing 的失败深度是 244 鈥 ? 70 m 并且在大约 270 鈥 ? 专注 60 m 深。这些损坏位置主要在划分的房顶上面在垂直的节根据岩石层的三个地区位于弯曲地区。通常， casing 以前开始使脸线变形或损坏大约 30 鈥 ? 50 m。特殊形成结构和岩石团性质是 casing 失败，高采矿高度和快进展速度的直接原因是为岩石质量的基本原因损坏。然而，到 casing 失败的地上凿穿配置和间距不是很清楚的。

Impact of Reclamation in Coal Mining Subsidence Area on Urban Spatial Expansion of Huaibei City

Based on the GIS data platform,and taking the spatial analysis as the main means,this paper explored the impact of reclamation in coal mining subsidence area on urban spatial expansion of Huaibei City. The analysis took the time evolution of urban space development as the basis,took the sectors,circle rings and sub-district offices as the basic spatial units. From the aspects of urban expansion rate,expansion direction,function and construction intensity,it analyzed the impact of reclamation on the urban spatial expansion. In addition,it analyzed the correlation between the reclamation utilization of the subsidence area and the changes in spatial expansion. Finally,it summarized the characteristics of the impact.

Optimum location of surface wells for remote pressure relief coalbed methane drainage in mining areas

Based on engineering tests in the Huainan coal mining area,we studied alternative well location to improve the performance of surface wells for remote pressure relief of coalbed methane in mining areas.The key factors,affecting location and well gas production were analyzed by simulation tests for similar material.The exploitation results indicate that wells located in various positions on panels could achieve relatively better gas production in regions with thin Cenozoic layers,low mining heights and slow rate of longwall advancement,but their periods of gas production lasted less than 230 days,as opposed to wells in regions with thick Cenozoic layers,greater mining heights and fast rates of longwall advancement.Wells near panel margins achieved relatively better gas production and lasted longer than centerline wells.The rules of development of mining fractures in strata over panels control gas production of surface wells.Mining fractures located in areas determined by lines of compaction and the effect of mining are well developed and can be maintained for long periods of time.Placing the well at the end of panels and on the updip return airway side of panels,determined by lines of compaction and the effect of mining,would result in surface wells for remote pressure relief CBM obtaining their longest gas production periods and highest cumulative gas production.

安徽省两淮煤田废弃煤炭矿井剩余资源综合调查、开发利用现状及展望

随着去产能政策和能源供给侧改革的深入推进,安徽省两淮煤田先后关闭了大量资源枯竭、经济亏损、产能落后的煤炭矿井。本文在综合调查两淮煤田废弃煤炭矿井剩余资源潜力的基础上,梳理了两淮煤田废弃煤炭矿井资源开发利用现状,分析了当前面临的主要问题。研究结果表明:截至2023年底,两淮煤田63处废弃煤炭矿井剩余煤炭资源约24.33亿t、煤层气约102.83亿m^(3)、可利用地下空间约7383.80万m^(3)、天然焦约3.45亿t,此外还有丰富的矿井水、地热和土地等其他可利用资源,具有良好的资源开发利用潜力。虽然目前两淮煤田在废弃煤炭矿井煤层气、矿井水、土地和共伴生矿产等资源开发利用方面已取得了一定的经济效益与社会价值,但仍然面临基础资料缺失、管理体系不完善、资源开发利用模式单一和利用率低等一系列问题。针对上述主要问题,本文从信息化建设、基础理论研究和探索资源开发利用模式三个方面提出了建议与展望,以期加快开发利用两淮煤田废弃煤炭矿井资源,提高资源利用率。

淮南矿区1/3焦煤二次氧化煤样孔隙特性实验研究

采空区二次氧化煤样自然发火为煤矿安全生产带来了巨大隐患。以淮南矿业集团顾桥煤矿1/3焦煤为研究对象,利用实验研究的方法,系统研究了不同预氧化温度和预氧化时间对煤孔隙特性的影响,研究发现:新鲜煤样和不同预氧化处理煤样的等温吸附曲线均呈典型的第Ⅱ类等温吸附曲线;预氧化处理对煤中孔隙的影响主要集中在0.45~20 nm,其中,2~4 nm内微孔的数量和总孔容在减少,在4~20 nm内的孔隙的数量和总孔容则显著增大;煤样的比表面积随着预氧化温度的提升呈现出先增大后变小的趋势,并在70℃时达到最大值;预氧化处理后,孔径处于0.45~5.9 nm时,孔隙的数量和总孔容有较大的变化。研究成果可为采空区自然发火防控提供必要的科学理论支撑。

淮南矿区煤层顶板分段压裂水平井抽采技术及效果研究

淮南矿区为典型高瓦斯矿区,煤层碎软、渗透率低、瓦斯含量偏高、抽采难度大,为探讨地面煤层气顶板分段压裂水平井在矿区的技术可行性与瓦斯治理效果,在分析矿区主要煤层13-1煤储层特征基础上,采用应力解除法进行了煤层三向地应力测试,结果显示三向应力场类型主要为σ_(h,max)>σ_(v)>σ_(h,min),具有实施顶板分段压裂水平井技术的充分条件;利用MFrac Suite软件分别模拟了水平段距离煤层1、3、5 m时的压裂缝参数,压裂缝半长最大107.33 m、最小89.47 m,具有理想的压裂效果,说明顶板分段压裂水平井在淮南矿区具有比较好的地质适应性与可行性。以潘一煤矿13-1煤层“L”型顶板分段压裂水平井CBM01井为研究对象,采用井下钻孔检测与数值模拟等手段综合分析了瓦斯治理效果,结果显示CBM01井抽采415 d即显著降低了煤层瓦斯压力与瓦斯含量,距离水平井50、65 m处瓦斯压力由6.4 MPa分别降至2.6、2.7 MPa,降低幅度均超过55%,水平段两侧各15~20 m范围内瓦斯含量由13.5 m^(3)/t降至最大9.11 m^(3)/t、最小6.92 m^(3)/t,平均7.92 m^(3)/t,约10 m范围均降至8 m^(3)/t以下。最后,采用数值模拟方法预测了CBM01井抽采10 a的产气效果及瓦斯治理效果,气井抽采10 a累计产气约272.08×10^(4)m^(3),水平段倾向单侧约150 m范围内气含量均降至8 m^(3)/t以下、压力均降至3 MPa以下。综合研究结果表明,煤层顶板分段压裂水平井技术在淮南矿区瓦斯治理方面均具有较大的优势和应用效果。

分段多簇密切割压裂技术在淮南矿区煤层气抽采中的应用

针对淮南矿区碎软低渗煤层瓦斯抽采技术难题,以13-1煤层为例,在分析煤层及其顶底板概况的基础上,采用煤层顶板分段压裂水平井技术,充分利用水平井水平段,单段分3簇射孔,簇间距25 m,实现分段多簇密切割体积压裂改造。微地震监测结果表明,单段裂缝长度102.5~211.4 m,缝高17.3~27 m,裂缝主体向下延伸,实现了井筒与煤层的沟通。排水采气效果表明,最高产气量1519 m^(3)/d,取得了良好的产气效果。研究成果为淮南矿区煤层气地面预抽和瓦斯区域治理提供了工程借鉴。

淮南矿区地应力场分布特征及其演化过程

本文提出一种水压致裂和应力解除地应力测试之间数据转换和有效性验证的方法,统计得到了淮南矿区500~1050 m埋深范围内84组有效地应力测试数据,绘制地应力分布矢量图,结合淮南矿区地质构造特征和历次构造运动,回归分析了淮南矿区地应力场分布特征及其演化过程,得出如下结论:淮南矿区地应力场类型整体为构造应力场,应力场量级以高应力场为主,局部属于超高应力场;随着埋深的增加,最大水平主应力、最小水平主应力和垂直主应力量值逐渐增大,水平应力增加幅度小于垂直应力,应力场类型表现出由构造应力场向自重应力转变的趋势;淮南矿区多数测点最大水平主应力方向为NEE-WE向,局部为NW-SE向,区域构造主应力场方向大部分继承了喜马拉雅运动期的NEE-EW向,局部保留了燕山运动中期的NWW-SEE向;新生代松散层在煤系地层堆积,决定了垂直应力的大小。

淮北矿区地表拉张裂隙区耕地土壤主要养分特征

[目的]分析采煤沉陷导致的地表拉张裂隙对耕地土壤质量的影响,评估采煤沉陷前后土壤养分变化,为沉陷区土地采前—采中治理提供理论基础。[方法]以淮北矿区孙疃矿地表拉张裂隙区为研究区域,分别在沉陷前(2019年6月)、沉陷后(2019年12月、2020年7月)采集样品,沉陷前布设5个采样点(T_(1)—T_(5)),沉陷后选择两条典型纵向拉张裂隙,由沉陷斜坡坡顶到坡底将沉陷区划分为A,B,C 3个分区,在裂隙两侧设置13个采样点,每个采样点沿深度方向每隔20 cm采集一个土壤样品,分别测试含水率、有机质、速效钾、速效磷、全氮和全磷含量6个指标。[结果]拉张裂隙区两次采样土壤含水率、有机质、速效钾、全磷含量存在显著差异(p<0.01),速效磷和全氮差异性不显著(p>0.05);通过主成分分析得到研究区第一、二主成分分别为有机质、全氮、全磷(受负面影响)和含水率、速效钾(受到正面影响);根据综合养分评价—主成分分析法发现裂隙区综合养分与对照点相比总体下降,但拉张裂隙区内养分从沉陷斜坡坡顶至坡底逐渐上升。[结论]地表拉张裂隙在采煤沉陷区分布广泛,是造成沉陷区耕地质量下降的主要原因。

淮南阜东矿区二叠系砂岩高盐地下水低硫酸盐特征及成因机制

矿区地下水水文地球化学研究对矿井水防治和水资源综合利用具有重要意义。针对安徽淮南煤田阜东矿区二叠系砂岩水低硫酸盐问题,通过水样采集测试,采用多元统计方法,结合水文地质条件分析和硫氧同位素技术,研究砂岩水水化学特征、水-岩作用以及低硫酸盐成因。结果表明:研究区二叠系砂岩水呈弱碱性,TDS平均值为1842.35 mg/L,属于微咸水,水化学类型主要为Cl-Na型、HCO_(3)-Na型和Cl·HCO_(3)-Na型。SO_(4)^(2-)平均质量浓度为37.48 mg/L,明显低于淮南煤田东部潘谢矿区和淮北煤田二叠系砂岩水。主要水-岩作用为蒸发岩(氯盐岩和硫酸盐岩)和硅酸盐岩矿物溶解,存在阳离子交替吸附作用。由于边界阻水断层切割,二叠系砂岩含水层四周均为相对隔水边界,且埋藏较深,富水性弱,水动力条件较差,形成了一个封闭–半封闭的水文地质单元,具有较强的硫酸盐还原环境,有利于硫酸盐细菌还原,脱硫酸作用明显,导致δ^(34)S升高,砂岩水硫酸盐含量偏低。研究成果可为类似条件矿区涌突水水源识别提供依据。

高潜水位资源型城市水域转化及其碳排放分析

从土地利用转型角度研究高潜水位资源型城市的水域转化及其碳排放,为低碳背景下的水资源治理提供科学支持和有效依据。以淮南市为例,通过Google Earth Engine平台调用随机森林和Landsat系列数据,对1987~2019年进行水域时空演变分析,并对2007~2019年进行土地利用分类,构建水域转化矩阵,运用碳排放系数法,估算淮南市和矿区水域与其他地类相互转化产生的碳排放。结果表明,1987~2019年,淮南市和矿区的水域面积总体上呈增长趋势,增量分别为87.98km 2和68.20km 2;在空间上,淮南市水域变化主要分布于矿区;2007~2019年,水域与耕地相互转化最为频繁,主要是耕地转化为水域,该过程主要发生在矿区;淮南市和矿区水域转化产生的碳排放在2007~2013年分别呈碳源和碳汇,2013~2019年均呈碳汇。淮南市和矿区水域转化呈碳源/碳汇主要取决于水域与建设用地相互转化产生的碳排放量。

集成DInSAR与SBAS InSAR的淮南丁集煤矿地面沉降监测

矿区地面沉降具有“快速”位移和高度非线性的特点,常用的DInSAR和SBAS InSAR均无法获得连续高精度的地面沉降监测结果。本文基于覆盖淮南丁集煤矿的17景Sentinel-1 SAR影像分别进行累积DInSAR和SBAS InSAR处理,利用Kriging插值对两种差分干涉技术得到的结果进行集成,获取2020年10月17日~2021年4月17日期间的矿区地面沉降信息,并对监测结果进行评估和分析。研究结果表明:丁集煤矿开采沉降现象严重,监测时段内丁集煤矿共有4个沉降漏斗,DInSAR和SBAS InSAR监测到的沉降位置、范围和变化趋势基本吻合,但两者所得的沉降量差异较大。而基于Kriging插值的DInSAR和SBAS InSAR集成结果,在沉降漏斗边缘区域很好地保持了SBAS InSAR的监测精度,并且有效地解决了SBAS InSAR在沉降漏斗区无法获取高相干像元产生空洞的问题,得到了连续高精度的矿区地面沉降结果,为矿区沉降监测提供了有效途径。

淮南矿区煤自燃指标气体及特征参数

为研究淮南矿区煤自然发火过程中的燃烧特性,采用程序升温实验装置,测试了淮南矿区6个不同煤矿中煤样的自燃特性,分析各煤样的CO、CO_(2)、CH_(4)、C_(2)H_(6)、C_(2)H_(4)气体的变化规律,计算并探讨耗氧速率、放热强度及极限参数在不同氧化阶段的变化。结果表明:CO、CO_(2)、CH_(4)、C_(2)H_(6)、C_(2)H_(4)气体均随温度升高呈现增大趋势,并在干裂温度后均表现出近指数增长。CO与C_(2)H_(4)气体可选作为预测淮南矿区煤自燃发展进程的预测指标性气体。耗氧速率与放热强度的变化趋势类似,临界温度前增长较为缓慢,后均呈抛物线式增长,而丁集与潘三两煤样耗氧速率与放热强度的变化较为突出。上限漏风强度随温度升高先减小后增大;下限氧体积分数与最小遗煤厚度则随温度升高,先增大后逐渐减小,且变化趋势相似。淮南矿区新庄孜煤矿的煤样氧化性能最为稳定。

钱营孜矿F_(22)高角度正断层防水煤柱留设宽度研究

高地应力作用下煤层采动诱发断层活化引起的承压水突涌,是深部开采矿井水害的主要形式之一,而预留断层防水煤柱依然是防止断层活化导水最主要的方法。以钱营孜煤矿F_(22)高角度正断层为典型实例,依据已有的钻探、物探和巷探资料,基于煤矿具体的水文地质和工程地质条件,以现场及室内试验数据为基础,采用有限差分数值分析方法对钱营孜矿F_(22)断层下盘靠近断层带的W3221工作面开采后防水煤柱的留设宽度进行了研究;同时根据理论公式对F_(22)断层防水煤柱的宽度进行了计算验证。结果表明:当煤柱宽度小于40 m时,断层带顶、底界面应力变化幅度及位移差会显著增加,煤层顶、底板的位移变化幅度也明显增大,断层带顶部出现塑性破坏区并且范围逐渐扩大;综合得出宽度为40 m的防水煤柱可有效防止断层活化突水。

2000—2020年淮南矿区土地利用变化对碳源/碳汇时空格局的影响

[目的]分析淮南矿区2000—2020年土地利用碳源/碳汇时空格局分布特征,为淮南市国土空间规划及未来低碳调控政策制定提供依据。[方法]以淮南矿区为研究对象,选取2000,2010,2020年3期土地利用数据,以格网尺度量化不同土地利用变化发展阶段下碳源/碳汇/碳排放的时空格局,基于冷热点分析碳源/碳汇/碳排放的空间格局。[结果]①2000—2020年,土地利用类型由单一用地为主转换多种土地利用类型同时发生,其中,建设用地面积增大,导致碳源效应增强,碳汇效应相对减弱,碳排放量持续增加,碳源年增加量为2.76×10^(6) t,碳汇年增加量仅为130 t,碳排放年增加量为2.76×10^(6) t;②碳源和碳排放空间分布特征基本一致,中部建成区和西北矿区是碳源和碳排放的主要集中区,碳汇主要聚集在东部、西部边缘区和西部部分矿区;③中部建成区是碳源和碳排放的显著热点、热点区域,以显著热点变化特征为主;显著冷点和冷点主要分布在研究区东部、西部边缘区域和西北部分矿区。[结论]淮南矿区的碳减排和低碳效应需要着重关注北部大面积的平原耕地区域,控制该区域矿区煤炭资源开采和建设用地开发,应加快塌陷水域修复工作;南部城市化进程快速增加的同时需适度增加林地和草地等生产性碳吸收能力区域面积,避免建设用地无限制扩张。

淮北古近系“红层”工程地质特性及不良地质分区研究

我国“红层”分布广泛,“红层”成分复杂和结构特殊,极易诱发地质灾害。以淮北矿区信湖煤矿82采区为研究区,通过室内试验,从矿物成分、微观结构、物理力学特性和水理特性4个方面研究了淮北古近系“红层”工程地质特性,基于古近系“红层”工程地质特性,结合层次分析法,建立了“红层”潜在诱发灾害工程地质模型,提出了9个指标作为“红层”潜在诱发灾害的主要地质因素,对信湖煤矿82采区“红层”诱发矿井地质灾害进行了不良工程地质分区评价。研究结果表明:古近系“红层”以泥岩为主,抗压强度低,微观结构较差,稳定性差,含大量的亲水矿物,具有较强的亲水膨胀和崩解性。整体上,82采区范围内古近系“红层”覆岩结构相对稳定,“红层”诱发矿井地质灾害隐患易发生程度从西北至东南逐渐增加,其中:南部及东南部和采区范围内断层附近灾害隐患最强,西部局部地区较安全,中部及北部大部区域内较危险。