防爆无缆遥测地震仪在煤矿槽波勘探中的应用

透射槽波勘探是煤矿井下工作面内构造探测的首选技术,具有探测范围大、准确率高等优点。针对井下槽波勘探仪器笨重等原因,研制了矿用无缆遥测地震仪,具有无缆、无需主机和通讯电话线等独特优点,使得仪器便携,施工简单,并已取得防爆证和MA认证,具备了240道的施工能力。通过在煤矿井下多个槽波探测项目的工程实践,验证了仪器的优越性能,且取得了很好的地质效果。     

采用槽波地震仪探测井下工作防水煤柱

本文介绍了峰峰矿务局三矿应用匈牙利产槽波地震仪，在８００ｍ巷道中，应用反射测量方法对不煤柱进行了测量逐年增加地数据进行处理后，认为在测量的第三段防水煤柱宽度应采取措施，该结果最后由钻孔所验证。     

微型检波一体化三分量地震仪及其应用

讨论了一种微型便携式地震仪的设计思路,该仪器具有本安防爆,重量轻、低功耗、高精度、高采样率等特点,内置三分量检波器,采集数据原位数字化且原位存储,能极大限度地抵抗外界干扰,提高采集信号的信噪比,实现了地震勘探检波一体化的理想采集条件。该仪器适用于恶劣环境条件下的高精度浅层多波勘探,如岩土体强度的原位测试、残余煤厚探测与工程检测等。通过实际应用证明该仪器应用范围广阔。     

井下无缆通信中谐变电偶极子的场

无线通信是地下工程如煤矿开采中重要的通信方式之一.特别是在灾害发生,其他通讯方式失效时,无线通信往往成为应急情况下唯一的联系方式.井下通信机采用偶极式发射与接收,但在有耗大地媒质中,使得井下通信的偶极场与通常经由空中发-收的无线电通信不同.本文利用全空间有耗媒质中谐变场的推迟位,在准静态条件下导出了电偶板子场的闭合解析公式,分析了谐变偶板子天线的方向性和场区以及无线通讯中场区与大地电阻率、通讯频率、通信距离等之间的关系.井下实验结果表明,有耗媒质中的电偶极源无缆通信是可行的,在适当的条件下,通信距离可达到880 m.     

新型矿用无缆钻孔测斜仪研究及应用

介绍新型矿用无缆钻孔测斜仪组成、工作方式、技术指标及关键部件设计等.通过煤矿井下钻孔使用,表明该无缆钻孔测斜仪设计合理,使用方便,精度达到测量要求.     

槽波地震仪的发展和DYSD─Ⅲ型矿井数字地震仪

回顾了矿井槽波地震仪的发展历史及最新成果。介绍了DYSD—Ⅲ型矿井数字地震仪的技术特点、指标及功能。     

煤矿反射槽波探测技术研究评述

反射槽波可用于单条巷道内探测巷道两侧和掘进前方一定区域内的断层等异常地质构造。目前该项技术已在我国多数矿井开展过探测试验和工程应用,对采掘危险区治理、工作面布置和采掘方案设计等生产环节起到了重要的指导作用。阐述了反射槽波的处理方法和原理,比较了面对巷道的侧帮和掘进前方2种不同探测区域时,反射槽波数据和处理方法的异同之处,着重对反射槽波的叠加成像、偏移成像以及掘进工作面超前成像3类成像方法的技术原理、适用条件和研究进展进行了梳理和分析,总结了反射槽波在巷道侧帮与掘进前方断层、采空区以及陷落柱探测方面的典型案例。在此基础上提出进一步提高探测能力的改进方向：研究适用于槽波频散性的反褶积方法,有效压缩反射槽波并依据频散速度准确偏移归位,提高成像分辨率;通过极化处理求出槽波的偏振方向,从而减少“画弧”现象;借鉴束偏移技术,选取特定方向的槽波参与成像,提高成像信噪比;研究影响反射槽波信号强弱的地质条件和采集条件,在不增加震源能量的条件下有效增强反射槽波;研制新型震源,提高反射槽波探测应用的安全性和适用性。对反射槽波未来的应用方向进行展望,以期促进反射槽波探测技术发展,为煤矿安全高效开采提供保障。     

单片机技术在矿井无缆组合测井仪中的应用

介绍了利用单片机技术进行矿井无缆测井仪的设计、系统功能的控制及单片机在探管和同步机中的扩展技术、主要技术参数的实现、智能控制的硬件和软件设计等。      

无缆有缆两用数字测井系统简介

全面介绍了无缆测井关键技术的解决思路和部分实施办法。重点介绍了野外无缆测井深度传输实验结果。该系统在煤田测井、石油测井及钻孔丈量中有广泛的应用前景     

中心通缆钻杆及其在煤矿井下定向钻进中的应用

针对煤矿井下定向钻技术对钻杆的随钻测量通讯和强度要求,钻杆采用中心通缆方式,可实时传输钻孔随钻测量信号。采用高强度管材、特种螺纹丝扣结构、摩擦焊技术,可提高钻杆抗拉、压、弯、扭强度。并根据现场使用中存在的问题给出了解决方法。大佛寺煤矿随钻测量应用实例说明中心通缆钻杆满足最大孔深1200 m的随钻测量通讯和钻杆强度要求,朱仙庄梳状孔应用实例说明中心通缆钻杆满足最小弯曲半径54 m定向孔施工,哈沙图煤矿定向钻孔应用实例说明中心通缆钻杆满足急倾斜58?煤层定向孔施工。     

煤矿井下随采地震探测技术发展综述

煤矿井下地震勘探的炸药震源受火工品管控影响大,且无法实现煤矿开采动力地质灾害的监测预警;随采地震是以采煤机为震源的地震探测新技术。本文回顾了国内外随采地震技术的研究现状,介绍了随采地震的方法原理和独特优势,并开展了一些先导性的试验研究利用。结果表明：采煤机震源具有激发能量强、频带宽、安全绿色经济、可重复等特点,可以作为随采地震探测的被动震源;采煤机震源与炸药震源的地震炮集记录接近,后者单炮信噪比相对较高;随采地震数值模拟、大数据动态处理等关键技术急需协同攻关。尽管随采地震尚处于试验研究阶段,但是它将成为未来透明工作面三维动态地质建模、开采动力地质灾害监测预警等重要手段,代表了今后煤矿智能探测技术的发展方向。     

Floor design in underground coal mines

Summary Floor failure and excessive heave in underground coal mines can jeopardize the stability of the whole structure, including the roof and pillars, due to differential settlements and redistribution of stress concentrations. Besides, floor failure is detrimental to haulageway operation and can lead to unacceptable conditions of high deformation. Thus, the design of any underground opening must consider roof/pillar and floor as one structural system.This paper presents guidelines for the design of mine floors, including the necessary field and laboratory investigations and the determination of the bearing capacity of floor strata. The design methodology is based essentially on a modified Hoek-Brown rock mass strength criterion. The main modifications are the introduction of the concept of the point of critical energy release to account for the long term strength, the inclusion of tensile strength and the adoption of a lithostatic state of stress in the rock mass. The determination of the dimensionless parametersm ands result from correlations with the RMR (rock mass rating) of the Geomechanics Clasification. Nine case histories, both in longwall and room and pillar coal mining, were analyzed with the proposed methodology.     

Control of gas emissions in underground coal mines

A high level of knowledge is now available in the extremely relevant field of underground gas emissions from coal mines. However, there are still tasks seeking improved solutions, such as prediction of gas emissions, choice of the most suitable panel design, extension of predrainage systems, further optimization of postdrainage systems, options for the control of gas emissions during retreat mining operations, and prevention of gas outbursts. Research results on these most important topics are presented and critically evaluated. Methods to predict gas emissions for disturbed and undisturbed longwall faces are presented. Prediction of the worked seam gas emission and the gas emission from headings are also mentioned but not examined in detail. The ventilation requirements are derived from the prediction results and in combination with gas drainage the best distribution of available air currents is planned. The drainage of the gas from the worked coal seam, also referred to as predrainage, can be performed without application of suction only by over or underworking the seam. But in cases where this simple method is not applicable or not effective enough, inseam-boreholes are needed to which suction is applied for a relatively long time. The reason for this is the low permeability of deep coal seams in Europe. The main influences on the efficiency of the different degasing methods are explained. Conventional gas drainage employing cross measure boreholes is still capable of improvement, in terms of drilling and equipment as well as the geometrical borehole parameters and the operation of the overall system. Improved control of gas emissions at the return end of retreating faces can be achieved by installation of gas drainage systems based on drainage roadways or with long and large diameter boreholes. The back-return method can be operated safely only with great difficulty, if at all. Another method is lean-gas drainage from the goaf. The gas outburst situation in Germany is characterized by events predominantly in the form of ‘nonclassical' outbursts categorized as ‘sudden liberation of significant quantities of gas'. Recent research results in this field led to a classification of these phenomena into five categories, for which suitable early detection and prevention measures are mentioned.     

Gas emission prediction and recovery in underground coal mines

Strata gas can be released and captured from non-active and active gas resources either from virgin or relaxed strata, both prior to and when mining activities take place. The high and irregular gas emissions associated with high production longwall mining have provided a need to optimise the methods used to predict these gas levels and the ventilation requirements for gas dilution. A forecast of gas emissions during development drivage and longwall mining indicated possible gas and ventilation problems requiring the introduction of various gas drainage techniques and in maintaining the necessary air quantities in ventilation systems to satisfy the statutory gas limitations for various coal production rates. Although there are sound principles used in world-recognised methods of gas emission prediction, a new approach developed from long-term practical experience in underground gassy coal mine practices and gas-rock mechanics studies appear most suitable for local conditions and mining systems in use. The Lunagas ‘Floorgas' and ‘Roofgas' geomechanical and gas emission models offer an effective solution to these problems. Both programs are the most advanced engineering, numerical tools available to calculate gas source contributions to total gassiness and improve the accuracy and quality of gas control, gas capture technologies and ventilation system design.     

煤矿井下可退式卡瓦打捞筒的研制及应用

煤矿井下卡钻、埋钻导致的孔内断钻杆事故时常发生,目前常用的公母丝锥造扣的打捞方法成功率较低,不仅耗费大量的人力物力,还会影响煤矿开采生产进度。基于此,设计了井下可退式卡瓦打捞筒,通过外筒的螺旋锥面驱动卡瓦径向卡紧断裂的钻杆,实现起拔打捞井内钻杆。卡瓦抱紧钻杆的结构设计,提高了打捞筒对断裂钻具的把持力。控制环的键槽结构设计,实现了复杂工况下可退式操作。分析了打捞作业时钻机回转扭矩产生的切应力与打捞筒强度的关系、钻机起拔力产生的正应力与打捞筒强度的关系,为打捞筒壁厚参数设计提供理论支持;分析了钻机起拔力转换为卡瓦对钻杆抱紧力的公式,验证了卡瓦打捞筒打捞孔内钻具的可行性;试制的打捞筒在山西新源煤矿井下现场进行了打捞试验,试验表明其结构设计合理,打捞性能可靠。本研究为煤矿井下处理复杂钻孔断钻事故提供新型工具,为打捞工具结构设计提供了理论依据。      

煤矿井下水平定向钻进技术的发展

国内外煤矿井下水平定向钻进技术(HDD)的发展具有不同的技术路线,这涉及钻进设备和钻具、钻孔监测仪器的研发,钻孔轨迹控制理论的研究等。本文阐述了煤矿井下HDD技术在国内外的发展特点及我国在该领域未来几年的发展方向。     

煤矿井下钻孔内瓦斯浓度监测传感器研制

当前,煤矿井下钻孔作业时,瓦斯监测系统只能反映钻孔孔口处瓦斯抽采量,无法获得钻孔内某个区段的瓦斯抽采效果, 随着煤矿井下瓦斯抽采钻孔孔深增加,沿钻孔长度方向瓦斯抽采效果出现明显分区,不同孔深处有效抽采半径出现较大差异,导致煤矿井下瓦斯抽采钻孔布置难度较大,不确定性增加。针对此问题,设计一种煤矿井下钻孔内瓦斯浓度监测传感器,该传感器基于可调谐半导体激光吸收光谱(Tunable Diode Laser Absorption Spectroscopy,TDLAS)原理,可实现钻孔内多点同时在线监测,保证了孔内无源,实现了本质安全。首先,分析TDLAS瓦斯测量基本原理,从气体分子吸收光谱原理出发,介绍了激光光源的选择,并根据比尔?朗伯定律推算瓦斯气体浓度解算公式。然后,在此基础上进行瓦斯浓度监测传感器设计,包括光程设计、结构设计、保护工艺设计和孔中操作流程4方面。最后,从性能和可靠性2方面出发,进行相对误差测试、稳定性测试、响应时间测试、与非色散红外传感器性能对比和防水防尘测试。设计的瓦斯浓度监测传感器直径40 mm,长度80 mm,传感器本质安全,结构上能够很好地适用于煤矿井下钻孔内应用。性能测试中,传感器全量程最大相对误差2.8%,小于孔内瓦斯浓度±6%的监测标准;稳定性测试中,传感器数据的波动范围在0.015%,稳定性为0.28%,满足稳定性小于1%的要求;传感器的响应时间约为8 s,满足响应时间小于10 s的要求;与非色散红外传感器对比测试中,设计的TDLAS瓦斯浓度监测传感器的相对误差和响应时间都明显优于非色散红外传感器。可靠性测试中,传感器长时间处于高湿度环境中,其测量精度并未受到影响,保护工艺可有效防水。性能测试和可靠性测试结果表明,瓦斯浓度监测传感器能够很好地满足孔内瓦斯浓度监测需求,在煤矿井下孔中监测方面具有很好的应用前景。      

煤矿井下定向钻孔超长套管下放技术

针对煤矿井下定向钻孔超长套管下放成功率低、速度慢的问题,提出开孔段保直钻进、造斜段曲率控制、钻机驱动主动钻杆下放及套管导正等改进技术措施。在阳泉新景矿进行了现场试验,完成了3个满足煤矿井下水力压裂要求的定向钻孔超长套管下放,最大下深达到168 m,套管下放成功率达到100%,下套管平均工效由5.5 m/h最大提高至13.1 m/h,有效地解决了定向钻孔超长套管下放受限的难题。     

煤矿井下套铣打捞技术研究与应用

基于煤矿开采深度的增加,在复杂地层中进行定向钻孔施工发生卡钻事故的风险也在急剧增加。采用套铣打捞技术进行卡钻事故处理,能够提高事故处理的成功率,并起到保护原钻杆的作用,降低经济损失。文章分析研究了套铣打捞钻具的选择、冲洗液选择、工艺参数以及工艺方法,结合在玉溪矿和临涣矿打捞实例,优化了套铣打捞工艺及相关参数。     

Numerical investigation of groundwater outbursts near faults in underground coal mines

Permeable geologic faults in the coal seam can cause intermittent production problems or unexpected amounts of groundwater outburst from the underlying aquifers. With the acknowledgment of the basic mechanism for groundwater outbursts, the groundwater outburst along the fault zones in coal mines are numerically investigated using RFPA, a numerical code based on FEM. The fracture initiation, propagation, and coalescence in the stressed strata and the seepage field evolution in the stress field are represented visually during the whole process of groundwater outburst. The numerically obtained damage evolution shows that the floor strata could be classified as three zones, i.e. mining induced fracture zone, intact zone and fault reactivation zone, in which the intact zone is the key part for resisting groundwater outburst and directly determines the effective thickness of water-resisting rock layer. With understanding of the evolution of stress field and seepage flow in floor strata, the groundwater outburst pathway is calibrated and the transformation of floor rock mass from water-resisting strata to outburst pathway is clearly illuminated. Moreover, it is shown that geometrical configuration, including inclination angle of faults and seam drop along faults, have an important influence on groundwater outburst. Finally, based on geological, hydrogeology survey and numerical results, the mechanism analysis of groundwater outburst in an engineering case is studied, which can provide significantly meaningful guides for the investigation on mechanism and prevention of groundwater outburst induced by faults in practice.