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1.
The mining depth of main coal mines could reach around 600 m in eastern North China, and extends to the dept with speed of around 12 m/a. As the basement of eastern North China-type coal mine, the Ordovician karst aquifer is the main water source that influences the carboniferous coal seam mining. As the deep karst water has large buried depth and high water pressure (8–12 MPa), with10–30 m space between high pressure aquifer and coal seam, the geological area of deep coal occurrence is often forbidden for mining. Environmental damage, to a greater or lesser degree, is caused by coal mining. On the basis of analyzing the hydrogeological conditions of mining areas, this paper introduces the hydrogeological survey work of ultra-high confined karst water deep in the coal seam floor within researched region for preventing and controlling water disaster of the mine. After researching into the hydrogeological investigation data in the researched region, we explored the hydrodynamic and water chemical characteristics of deep karst water by using pumping test, dynamic observation, and dewatering test. Finally, this study suggests that the hydraulic pressure of deep mining could be mined, on the circumstances that reasonable and effective of water prevention measures are taken based on a detailed survey on water abundance of deep karst.  相似文献   

2.
大采深工作面煤层底板采动破坏深度测试   总被引:1,自引:0,他引:1  
针对邢东矿大采深的情况,利用现场底板注水试验对2121工作面底板采动破坏深度进行了测试研究,依据单位注水量的动态变化以及注水孔与采线之间的距离关系,确定了底板破坏深度。试验结果表明:该工作面底板破坏深度为32.5~35m,比300m采深以内的工作面实测深度(9.15~12.0m)增加2倍以上,说明随着开采深度的增加,煤层底板采动破坏深度呈明显增大的趋势,因此,在水压和破坏深度二者同时增加的条件下,2121工作面深部煤层开采的突水危险性远远大于浅部煤层。测试结果为邢东矿大采深工作面的防治水方案的制订提供了科学依据。   相似文献   

3.
注浆改造是华北型煤田下组煤开采的有效防治水技术之一。但是目前该项技术只能解决浅部上组煤问题,随着采深的增大,注浆改造煤层底板薄层灰岩含水层已不能满足安全开采条件。以东庞矿下组9号煤开采为例,分析了奥陶纪峰峰组岩溶含水层富水特征,研究了对奥陶系顶部进行注浆改造的可行性和相关技术问题,得出,对东庞矿奥灰上部进行注浆改造在技术上是可行的,合理的注浆改造厚度为40 m。试验性注浆结果表明,钻孔涌水平均堵水率达到74%,注浆效果良好,并提出了下一步防治水工作建议。   相似文献   

4.
Determining the failure depth of coal seam floor is necessary for safe mining operations, especially when the coal seam is located above confined aquifers with high water pressure. Geomechanical, geophysical, and hydrogeological data collected during the longwall mining of the first working face of coal seam no. 16 in the Nantun coal mine, Shandong Province, China, were used to calculate the failure depth of the coal seam floor above the Ordovician limestone confined aquifer. The multiple method approach employed by this study made use of the plastic sliding theory, empirical formulas, water injection test, and numerical simulation. Multiple methods can compensate for and validate each other and also overcome the intrinsic limitations of any single method. The results showed that the most appropriate value of the failure depth of the coal seam floor in the mine was 14.6 m and this value proved useful for knowing the effective thickness of water pressure-resistant layer below the coal seam. The failure depth also proved to be an important parameter when preventing groundwater flow into the mine from the coal seam floor.  相似文献   

5.
随着煤矿开采深度的不断增加,带压开采已经成为深部矿井普遍应用的一种采煤方法,而带压水上采煤的关键问题之一是确定采动引起的底板破坏深度。针对董家河煤矿5号煤层开采引起的底板采动破坏深度开展相关研究,以该矿的507综采工作面开采为工程背景,采用理论分析和数值模拟相结合的办法,动态再现了整个底板岩层渐进破坏过程,并得出底板岩层的最大破坏深度为10~11 m,该结果与现场实测结果一致;同时给出了该矿底板岩层破坏深度与工作面斜长和埋深关系的经验公式。该结论为董家河煤矿带压开采工作面煤层底板突水预测与防治提供了科学依据。   相似文献   

6.
鄂尔多斯盆地准格尔煤田某矿石炭-二叠系6煤层为特厚煤层,平均可采厚度17.0 m,其底板受到灰岩水的威胁。针对这种情况,现场采用分布式光纤传感及跨孔电阻率CT原位综合测试技术,先后获得了采动过程中多个工作面底板破坏应变场及地电场响应特征数据。结合岩样加载变形破坏的判别阈值参数及探测实践,对采区内4个工作面底板测试数据进行综合分析,获得了区内底板岩层破坏空间特征及其规律认识。分析认为底板破坏在垂向上具有明显的分带性,采区工作面底板破坏深度在7.2~16.5 m,主要破坏层位在细砂岩以上层段,扰动影响最大深度在33 m左右,主要扰动层位在砂质泥岩以上层段;底板破坏在横向上具有超前性,超前距离在25~60 m范围;区内工作面底板破坏特征具有一定的相似性,动压影响下的底板损伤程度在空间上呈东北区域浅、西南区域深的分布规律。原位测试所获得的数据对区内6煤层水害防治及安全开采具有指导作用。   相似文献   

7.
In the absence of a suitable coal seam to serve as the protective seam in deep mining, an innovative solution of using the soft rock seam as the protective seam mining has been put forward. Taking the Luling Coal Mine as the engineering background, theoretical analysis and similar simulation experiment were conducted to study the key technologies used in soft rock protective seam (SRPS) mining. This included the characteristics of the pressure-relief gas source and accumulation zone, and the pressure-relief gas extraction of the protected seam. The results show that after mining the SRPS, the pressure-relief gas rushing out of nearby coal seams has become the major gas source in SRPS mining. An omni-directional stereo pressure-relief gas extraction system was developed, which consisted of techniques such as buried pipes in the goaf, ground extraction wells, intercepting boreholes, and seam-crossing boreholes. During the investigation, the total pressure-relief gas extraction flow amounted to 29.5 m3/min, and the gas pre-extraction rate reached 66.6% for the overlying protected seams (seams 8 and 9). The investigation into the protective effects in the cut hole showed that the maximal gas pressure and content were 0.35 MPa and 4.87 m3/t, respectively. This indicated that drilling extraction boreholes in the gas accumulation zone played a key role in obtaining an improved pressure-relief gas extraction effect. Further, these findings suggested that SRPS mining (in combination with omni-directional stereo pressure-relief gas extraction technology) could turn dangerous coal seams into ones with much less gas content, and hence free from gas outburst.  相似文献   

8.
深部煤层渗透性普遍较差,直井压裂开发单井产量低效果不甚理想,而U型水平井分段压裂开发煤层气技术已取得很好的效果。该项技术试验前必须进行适合该井型的地质评价。以鄂尔多斯盆地东缘延川南区块为例,首先分析影响水平井压裂产能的地质因素,主要为单井控制资源量、储层渗透性和煤层气解吸难易程度,其中单井控制资源量受含气量和煤层厚度影响,渗透性与煤层埋深、构造及煤体结构等有关,碎裂煤发育区渗透性相对好。而后假定吸附性能不变的前提下,利用数值模拟方法分别模拟了不同渗透率、含气量和煤层厚度条件下水平井压裂的产气情况,模拟结果表明水平井压裂后累计产气量与渗透率、含气量、煤层厚度正相关。最后在经济效益评价的基础上,查明适合水平井压裂的地质条件:渗透率>0.25×10–3μm2,含气量>12.3m3/t,煤层厚度>2.9m。该地质适用性评价标准在现场得到广泛应用,并收到了良好的开发效益。   相似文献   

9.
Coal and gas outburst disasters in coal seams are becoming more serious as coal mines extend deeper underground in China. To aid gas control in high-gas outburst coal seam group, this study performed research based on the geological conditions of the Xinzhuangzi coal mine in the Huainan coalfield. The laws of gas occurrence, the strength of the coal outburst, and the regional partition were studied. Simultaneously, we introduced the key protective seam mining technology and confirmed the mining sequence of coal seam groups. The results indicate that (1) each seam absorbs gas well, and the currently measured gas content is up to 15.0 m3/t. (2) Although some differences about coal seams outburst intensity remain, the differences in the same group are very small. (3) The coal seam B10 was chosen as the key protective seam and was mined first; then adjacent seams were mined from bottom to top by layer within the roof of B10 and from top-to-bottom within the floor of B10 to guarantee each adjacent coal seam received the good effects of pressure-relief and increasing permeability. (4) The main methods of gas extraction in each protected seam are surface boreholes and net-like penetrating boreholes in the floor roadway, and related technical parameters were determined according to the degree of pressure-relief in coal seam. This in situ experiment indicates a method aiding the gas control problem and guaranteeing safe and highly efficient exploitation of high-gas outburst seams.  相似文献   

10.
为了提高深部煤层瓦斯含量的预测精度,提出了采用灰熵分析法对瓦斯含量影响因素进行研究,以潘三矿深部11-2煤层为例,根据灰熵关联度的大小选取不同的影响因素分别建立了GM(1,3)、GM(1,4)和GM(1,5)预测模型,依据精度检验结果选择精度更高的瓦斯预测模型。研究结果表明,影响潘三矿深部11-2煤层瓦斯含量的因素重要程度从大到小依次为:主断层距离、煤层埋深、煤厚、顶板砂泥比、煤层倾角。由此建立的3个模型的预测精度都在合格以上,其中GM(1,4)模型预测精度达到了1级,平均相对误差为5.063 6%,可采用该模型对11-2煤层瓦斯含量进行预测,为深部煤与瓦斯安全高效开采提供可靠依据。   相似文献   

11.
确定煤层顶板导水裂缝带高度可为顶板防治水、采掘工程布置、防水煤柱留设以及瓦斯抽采设计提供依据。采用井下仰孔注水测渗漏法,实测山西西山煤田镇城底矿8煤导水裂缝带高度为57.98 m,其中冒落带高度16.72 m,裂隙带高度41.26 m。依据实测结果并收集了8个矿综采一次采全高中硬覆岩下导水裂缝带高度数据,利用数理统计回归分析的方法,得出了适用于综采一次采全高中硬覆岩下导水裂缝带高度计算的经验公式,并与《煤矿安全规程》中相应经验公式进行对比分析,结果表明,该公式适用性好,而《煤矿安全规程》中有关公式应用于中厚煤层综采一次采全高开采条件预测,其误差较大。   相似文献   

12.
针对孤岛工作面煤层开采底板损伤问题,以河北葛泉煤矿11913孤岛工作面为研究对象,采用微震方法分析其底板破坏深度;并通过数值模拟对首采、跳采及孤岛3种工作面回采过程中围岩采动应力与底板破坏的规律进行了对比分析。微震测试结果显示11913工作面回采过程中微震事件主要发生在下巷,识别出工作面最大破坏深度20~25 m;基于COMSOL的11912首采、11914跳采及11913孤岛3个工作面数值模拟结果显示,11912首采与11914跳采条件下煤柱地应力集中状态变化不大,最大破坏深度小于11.56 m,仅发育至工作面底板的注浆改造层内部;而11913孤岛回采条件下,受到重复采动影响,工作面两侧煤柱应力集中状态骤增,最大破坏深度剧增至23 m,已发育至煤层底板的本溪组灰岩含水层。研究结果对于华北型煤田下组煤层开采底板破坏规律分析与不同类型工作面回采条件下底板水害防治有一定的参考价值。   相似文献   

13.
In China’s western coal mining area, the traditional room mining technology is facing coal pillar instability, mine earthquake, large-area roof subsidence in the goaf, surface subsidence, water and soil loss, vegetation deterioration, and other environmental problems. To solve the aforementioned problems and to improve coal recovery, the roadway backfill coal mining (RBCM) method was proposed as a solution and its technical principle and key equipment were presented in this paper. In addition, the microstructure and mechanical behavior (strain-stress relation in confined compressive test) of aeolian sand and loess backfill materials were studied for a rational backfill design for underground mines. Further, coal pillar stress, plastic zone change, and surface deformation of the RBCM schemes were studied using the FLAC3D numerical simulation software, and a reasonable mining scheme of “mining 7 m and leaving 3 m” was determined. The engineering application in Changxing Coal Mine shows that the RBCM method with loess and aeolian sand as backfill materials allows a stable recovery of coal pillars with a recovery ratio of more than 70 %. The maximum accumulated surface subsidence and the maximum horizontal deformation were measured to be 15 mm and 0.8 mm/m respectively, indicating that the targeted backfilling effect can help protect the environment and also control surface subsidence.  相似文献   

14.
以韩城矿区桑树坪煤矿下组煤3105工作面开采实际情况为背景,采用现场声波测试和数值模拟方法,对沿空留巷开采条件下煤层底板扰动破坏规律进行了研究。声波测试成果表明工作面底板扰动破坏深度为13.2~14.6 m,数值模拟成果显示工作面底板破坏深度为13.0~14.5 m,两种方法结果较为一致。通过与正常开采条件下底板破坏深度进行对比,结果表明,采用无煤柱式的沿空留巷开采技术不会对底板破坏深度造成较大影响。研究成果为国内底板带压工作面采用沿空留巷技术开采过程中底板扰动破坏规律的确定提供依据。   相似文献   

15.
Gas outburst disasters are becoming more serious as the underground coal mines become deeper in China, and a thick zone of deformed coal provides conditions favorable to coal and gas outbursts. The Daning coal mine’s main mining seam is the No. 3 coal seam with coal and gas outburst hazard, which often contains two normal coal sub-layers and one deformed sub-layer. Considering both the geological conditions of the coal seam and applications of the in-seam directional longhole drilling technology, a new schematic diagram of in-seam directional longholes for gas drainage is developed. The two borehole layout models of longwall panel and main entries for gas outburst disasters control have been successfully applied. The gas drainage rates of both models are >70 %, and the residual gas contents are both <8 m3/t, which can be considered that the gas outburst disasters were effectively controlled. To better guide gas drainage, gas drainage normal and failure modes have been obtained. Although in-seam directional longhole technology has been successfully applied for regional gas drainage with benefits to gas outburst control, there are also some problems that are detrimental to greenhouse gas reductions in gas drainage and gas utilization. The three main problems are air leakage failure in gas drainage, decreasing gas concentration and a low gas utilization ratio. To address the problems mentioned above, five improvements are suggested.  相似文献   

16.
回顾了我国煤炭企业组织实施和合作开展的煤矿区煤层气勘探开发进程。经过三十多年攻坚克难、不懈努力,我国煤矿区煤层气地面开发技术研究、工程试验和产业发展均取得了可喜的成绩,不仅在山西晋城矿区首次取得国内外无烟煤的煤层气开发成功,实现了煤层气规模化商业化生产,而且在安徽淮北矿区取得了碎软低渗煤层顶板水平井开发煤层气技术的重大突破,实现了碎软低渗煤层的煤层气水平井单井的高产稳产;煤矿区采动区煤层气井开发在安徽淮北、淮南,山西晋城等矿区实现了规模化工程应用。同时,梳理总结了依托“十一五”—“十三五”国家科技重大专项项目,在煤矿区煤层气地面开发理论及技术研究方面取得的主要成果及其应用效果,包括:煤层气井密闭取心技术与设备、碎软低渗煤层地面煤层气垂直井强化增产技术、碎软低渗煤层顶板和煤层水平井分段压裂开发技术、多煤层分层控压合层排采技术、低煤阶低气含量煤层地面煤层气开发技术、煤层气井极小半径多孔旋转射流侧钻水平井技术,以及煤矿采动区煤层气产量预测技术等。在此基础上,根据全国煤矿区煤炭开采发展趋势和需求,提出今后煤矿区煤层气研究应重点关注3个方向:穿浅部采空区/采动区的深部煤层气与煤炭资源协调开发、低...  相似文献   

17.
石浩  张杰  何乐 《探矿工程》2018,45(7):37-40
针对工作面回采后采空区瓦斯易超限问题,采用螺杆马达结合随钻测量技术的定向钻进工艺,在桃园矿1029工作面施工了3个长距离煤层顶板大直径定向钻孔,最大孔深531 m,累计进尺1701 m(含分支孔),通过精准控制钻孔轨迹,使钻孔沿煤层顶板裂隙带延伸,有效抽采煤层回采后采空区内瓦斯,总结了一套适用于采空区瓦斯治理的高位顶板长钻孔施工方法,保障了煤矿安全高效生产。  相似文献   

18.
根据实测平煤五矿己15煤层瓦斯含量和压力结果,从力能角度分析了地应力、瓦斯和煤强度对煤与瓦斯突出的影响,发现己四采区己15煤层受地应力作用,煤体弹性潜能远大于瓦斯膨胀能,即以构造应力为主的地应力为其突出最主要的影响因素;结合己四采区地质因素和己15煤层瓦斯可解吸量,确定该采区煤与瓦斯突出危险区的下限指标为原煤瓦斯含量达到5.4 m3/t,绝对瓦斯压力为0.79 MPa,该下限指标对应的煤层底板标高为–600 m。因此预测–600 m标高以浅为无突出危险区,–600 m以深为突出危险区。   相似文献   

19.
煤炭开采活动导致的煤层顶板覆岩地质条件变化及采动裂隙发育是损害地下关键含水层的直接原因,也是造成矿区生态环境退化的根源。煤层顶板覆岩结构中发育的厚砂岩作为一种典型的地质条件,其对覆岩采动裂隙的发育规律具有重要的影响。为此,在分析研究区主采煤层赋存地质条件及其分布规律的基础上,选择陕北煤炭开采区曹家滩煤矿主采2?2煤层顶板覆岩为地质原型,采用FLAC3D数值模拟平台模拟分析了厚砂岩不同厚度和位置对覆岩采动裂隙发育形态和发育高度的影响,并以此提出了相应的“采煤保水”建议。结果表明:研究区2?2煤层顶板覆岩中厚砂岩平均厚度25 m,距2?2煤层平均间距76 m;厚砂岩距煤层30 m时,覆岩采动裂隙表现为“矩形—L形—马鞍形”的动态变化特征,距煤层70 m时表现为“L形—倒梯形—马鞍形”变化特征,距煤层大于95 m时全程表现为“马鞍形”特征;覆岩采动裂隙最大发育高度随厚砂岩层位的升高而先减小后增大;厚砂岩厚度H≥30 m、距煤层间距L>95 m,或H≥60 m、L>60 m时,可有效阻挡采动裂隙向上发育贯穿厚砂岩;在充分考虑厚砂岩对覆岩采动裂隙发育规律的影响,选择合适的空间位置和开采阶段进行合理的覆岩减损和保水防治,实现“边采边治、边采边护”的绿色开采模式。该研究成果可为黄河流域中游陕北煤矿区煤炭开采与生态环境保护协调发展提供理论指导。   相似文献   

20.
安阳矿区多为高瓦斯和煤与突出瓦斯矿井。通过钻孔和矿井瓦斯资料分析,认为区内二1煤层瓦斯含量高,最高可达41.72m3/t。区内瓦斯赋存规律明显,具有南北分带、北低南高的分布特征,其展布规律主要受地质构造、煤层埋深、围岩、煤厚、变质程度、水文地质条件等因素的影响,而地质构造中的地垒、地堑造成的断块抬升、下降,断层的多期构造应力作用及其对煤层的剪切作用,褶曲等构造因素是造成矿区瓦斯分布不均衡的主要原因。  相似文献   

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