煤储层孔、裂隙系统分形研究

对煤层、煤样进行了宏观裂隙及显微裂隙的连续系统观测、统计,计算了煤中各级别裂隙的面密度维数;根据压汞法测出的煤中不同孔径段的连续比孔容数据,计算了煤中孔隙体积的分形维数。分析了分形九与煤层的孔、裂隙发育程度和煤变质程度的关系。为评革层气的吸附与解吸、扩散与渗流、煤与瓦斯突出预测及煤层有效渗透率估算提供了一种更加精确的方法。     

基于底板构造曲率的煤层高渗区预测

为预测古交区块8号煤层渗透率,基于最大构造曲率预测煤层裂缝渗透率原理,采用差分法计算煤层底板最大构造曲率,通过分析最大构造曲率、煤层厚度和裂缝间距之间的关系,构建预测煤层渗透率的数值模型。预测结果表明:古交区块煤层渗透率介于0.002～0.650 mD,北部煤层渗透率最高,东部最低;采用该模型预测的煤层渗透率明显高于试验测试的孔隙渗透率,而与试井、试验测试裂缝渗透的结果较为吻合,表明采用此模型预测煤层裂缝渗透率是可行的。     

三维地震多属性融合技术在O2裂隙发育带定量预测中的应用

随着煤矿开采深度不断增加,煤层底板灰岩含水层富水特征及突水危险性预测是煤矿深部智能安全绿色开采亟待解决的问题。本文利用灰色关联性分析与多元回归分析方法,结合三维多种属性融合关键技术,对煤层底板灰岩溶裂隙带进行精准定量预测。由于奥陶系(O)灰岩溶裂隙发育抽象系统包含众多因素,笔者特引入岩石RQD指标用来模拟构建数学模型,并将该数学模型用于定量预测奥陶系灰岩溶裂隙发育带。由淮北矿业集团孙疃煤矿83采区奥陶系灰岩裂溶隙发育带定量预测结果表明,此模型经过数学运算将多种地震属性融合后,构建出奥陶系中统O₂溶裂隙发育带定量表征参量,其拟合度达88.97%,提高了灰岩溶裂隙发育带预测精度,为煤层底板灰岩发育裂隙带的定量预测提供了一种新途径。     

煤田地质特征与煤层气地质因素关系的研究

本文探讨，论述了影响煤层气富集高产的煤层生气量，储气能力，煤层孔隙，割理，裂隙发育，煤层渗透率，煤层气解吸压力等地质因素，分析研究了煤田形成演化历史和构造地质特征对上述煤层气地质因素的影响控制关系，为煤层气资源地质评价和开发选区提供了理论依据。     

沁水南部柿庄南区块3号煤层现今地应力特征及其与渗透率的关系研究

为了研究沁水盆地柿庄南区块3号煤层地应力特征,揭示地应力对渗透率的影响规律,根据研究区3号煤层形成后的古构造应力场特征,划分出煤层褶皱不同部位叠加区,采用水压致裂法和声波测井互相印证法计算出煤储层地应力,应用实测和地质强度指标(geological strength index,GSI)相结合的方法得出煤储层渗透率,对煤层现今地应力与埋深的关系进行回归分析,查明了地应力随埋深的变化特征,在此基础上总结了地应力对煤储层渗透率的影响规律。结果表明:研究区煤层地应力随埋深增加呈线性增大;在700 m以浅地区,σVσHσh,现今地应力状态为大地静力场; 700～900 m,σH≈σV≈σh,为准静水压力场; 900 m以深,σHσVσh,最大水平主应力起主导作用,具有大地动力场特征。对于同一构造部位,煤储层地应力与埋深相关性较好,呈负指数关系;不考虑多期构造叠加时,应力差与渗透率关系不明显,考虑构造分期后,同一叠加区其应力差与渗透率符合指数关系。     

煤层气储层渗透性研究进展

煤储层渗透性是制约煤层气勘探选区的重要参数,影响渗透率差异分布的因素有很多,从裂隙系统的发育、煤储层有效应力、煤层构造演化、煤岩变质程度几个方面阐述了它们与高渗区空间分布的关系及其研究进展.对其研究技术、手段、主要认识及存在的问题等进行了系统的总结.对有效预测煤储层渗透性、发展渗透性描述理论、寻找有利勘探区带具有重要意义.     

利用构造—地层分析法预测阳泉—矿扩区构造

煤系中小型地质构造的发育与煤层的厚度以及砂体，泥岩分布特征有密切的关系。利用构造－地层法分析了阳泉一矿3＃煤层小构造的发育规律，预测了其扩区的小构造发育程度。     

浅埋煤层重复采动覆岩裂隙及漏风通道演化模拟研究

为了研究浅埋藏近距离煤层群重复采动下地表漏风对采空区煤自燃的影响,利用FLAC~(3D)数值模拟软件,对神东矿区补连塔矿回采不同阶段覆岩孔隙率的发育规律、塑性区分布以及覆岩垮落高度进行模拟分析。结果表明:(1)上煤层回采完毕后,覆岩裂隙发育呈"U"形分布,最大裂隙高度达130 m,尚未通达地表;下煤层回采完毕后,覆岩最大裂隙高度达162 m,贯通地表。(2)上煤层回采完毕后,覆岩在上煤层上方62 m处发生明显离层,离层区下方覆岩下沉高度1.75~4 m,离层区至上覆岩层下沉高度0.25~1 m;下煤层回采完毕后,离层区进一步发育,离层区下煤层采空区顶板垮落,上煤层采空区岩体进一步沉陷,最大下沉高度达7 m,离层区至上覆岩层下沉高度1~2 m。(3)在回采同一阶段,同一高度覆岩孔隙率变化率两侧大于中部;下煤层的回采使上煤层覆岩孔隙进一步发育,孔隙率变化率明显增大。     

吴寨矿井底板灰岩含水层富水规律分析

针对平顶山矿区吴寨矿一5煤层开采受底板灰岩水威胁的现状,分析了一5煤层底板灰岩含水层的基本特征,研究了岩溶裂隙的发育特征和分布规律,查明了富水分区.研究表明,灰岩含水层浅部岩溶裂隙较发育,随着深度增加,岩溶裂隙发育程度逐渐减弱.标高在-150 m以上为灰岩地下水强富水区;-150～-350 m为中等富水区;-350 m以下为弱富水区.根据物探结果,在矿井西翼-250～-340 m水平,煤层底板灰岩存在多个相互独立的异常区.     

利用构造-地层分析法预测阳泉一矿扩区构造

煤系中小型地质构造的发育与煤层的厚度以及砂体、泥岩分布特征有密切的关系。利用构造—地层法分析了阳泉一矿 3 #煤层小构造的发育规律 ,预测了其扩区的小构造发育程度     

Application of structural curvature of coalbed floor on CBM development in the Zaoyuan block of the southern Qinshui Basin

Based on controls of structural style and the position in coalbed methane(CBM)development,we used a method of curvatures to study its relations with CBM development parameters.We calculated structural curvatures of contours of the No.3coal seam floor of the Shanxi Formation in the Zaoyuan block of the Qinshui Basin and analyzed its relations with development parameters of coalbed methane wells.The results show that structural curvature is negatively related to coal reservoir pressure,while positively related to permeability.With an increase in structural curvature,the average production of coalbed methane wells increases at first and then decreases,reaching the highest production at 0.02 m-1 of structural curvature.Therefore,structural curvature can be an important index for potential evaluation of coalbed methane development and provide a basis for siting coalbed methane wells.     

A method of determining the permeability coefficient of coal seam based on the permeability of loaded coal

This study developed the equipment for thermo-fluid–solid coupling of methane-containing coal, and investigated the seepage character of loaded coal under different working conditions. Regarding the effective pressure as a variable, the variation characteristics of the gas permeability of loaded methane-containing coal has been studied under the conditions of different confining pressures and pore pressures. The qualitative and quantitative relationship between effective stress and permeability of loaded methane-containing coal has been established, considering the adsorption of deformation, amount of pore gas compression and temperature variation. The results show that the permeability of coal samples decreases along with the increasing effective stress. Based on the Darcy law, the correlation equation between the effective stress and permeability coefficient of coal seam has been established by combining the permeability coefficient of loaded coal and effective stress. On the basis of experimental data, this equation is used for calculation, and the results are in accordance with the measured gas permeability coefficient of coal seam. In conclusion, this method can be accurate and convenient to determine the gas permeability coefficient of coal seam, and provide evidence for forecasting that of the deep coal seam.     

低透气煤层预裂瓦斯运移数值模拟及抽采试验

针对高瓦斯低透气性煤层瓦斯抽采难问题,利用数值模拟软件RFPA^2D—Flow再现了采取煤层深孔爆破预裂后,瓦斯在煤层及爆生裂隙中的流动规律。研究结果表明,预裂圈内煤和岩石的孔隙率大大提高,煤层透气性显著增加,但当裂隙圈之间不相交时,瓦斯同样很难在完整的低透气性煤体中运移,因此只有当抽采瓦斯钻孔处在裂隙圈中才能高效抽采瓦斯。现场试验证实,低透气性煤层预裂后,有效导通裂隙增加,布置在裂隙圈内抽采瓦斯钻孔可以获得高效抽采瓦斯效果,从而降低煤与瓦斯突出危险性。     

保护层开采上覆煤岩变形移动及瓦斯抽采效果

根据潘三矿东四采区实际开采条件和回采工艺,运用数值模拟和现场试验相结合的方法,分析了近水平煤层保护层开采过程中被保护层应力、变形量、透气性系数在保护层开采过程中的演化机制。结果表明：保护层开采过程中,被保护层存在未受影响区（原始应力区）、增压区、过渡卸压区、稳定卸压区和重新压实区,被保护层边界区域附近过渡卸压区内的透气性系数为原始透气性系数的30倍左右,煤体应力下降,产生了一定的膨胀变形,大大提高了瓦斯抽采效果。     

平顶山矿区煤层气赋存特征及开发潜力

平顶山矿区二1煤层富含煤层甲烷气体,其资源量估算达302亿m3以上．本文通过对控制煤层气赋存的二1煤层的传层几何形态、地质特征、煤质变化、特别是物性特征的研究,指出本区二1煤层渗透性较好,渗透率随着围限压力增加而降低,且与判及发育程度、构造应力变化有密切关系．而二1煤层中的煤层气含量与煤层理深有着密切关系,随着深度增加而增加．通过综合分析指出了开发潜力较好的区块．     

红菱煤矿开采保护层对 煤岩体透气性的数值模拟

以红菱煤矿保护层开采为工程实例,通过开采11#煤层,对存在煤与瓦斯突出的7#煤层和12#煤层进行 卸压,利用FLAC3D数值模拟中小同步开挖的渗透率变化情况,对保护层开采过程中煤岩体的渗透性进行了分 析,得出了煤岩体透气性变化规律。结果表明:煤岩体的透气性随着工作面推进不断增强;开采保护层上覆岩体 的渗透率明显比底板岩体的渗透率大;卸压效果越好,渗透率越大。     

Strength criterion effect of the translator and destabilization model of gas-bearing coal seam

Coal seam destabilization inflicts damage to equipment, causes property loss and personnel casualties,and severely threatens mining safety and efficient production. To further understand this destabilization based on the basic theory of Lippmann seam destabilization, a mathematical model was introduced for gas pressure distribution by considering intermediate principal stress and support resistance.Subsequently, we established a translation model suitable for the entire roadway coal seam with rocky roof and floor by applying the unified form of yield criterion in the state of plane strain. We also obtained the analytic expressions of coal seam stress distribution on both sides of the roadway and the widths of plastic and disturbance zones. Afterward, we analyzed several typical cases with different material yield criteria, obtained the plastic zone widths of the coal seam under different gas pressures, and assessed the effects of support resistance, roadway size, and coal strength on coal seam destabilization. Results showed that: the results obtained on the basis of Wilson and Mohr–Coulomb criteria are considerably conservative, and the use of Druker–Prager criteria to evaluate the rockburst-induced coal seam destabilization is safer than the use of the two other criteria; coal seam stability is correlated with gas pressure;and high-pressure gas accelerates the coal seam destabilization.     

吉克煤矿首采区上行开采可行性分析

通过理论计算和数值模拟方法,对吉克煤矿首采区M11煤层上行开采的可行性进行了研究。结果表明,计算得出M11煤层开采后覆岩最大垮落带高度为8．47m,导水裂隙带高度为21．1m-32．4m,M9煤层位于导水裂隙带之内。数值模拟结果表明,M9煤层内部的垂直应力显著下降,垮落带和导水裂隙带高度分别为10m和36m,M11煤层开采对M9煤层的卸压效果明显。首采区利用M11煤层作为M9煤层的解放层是可行的。     

Application of pressure relief and permeability increased by slotting a coal seam with a rotary type cutter working across rock layers

Pressure relief to increase permeability significantly improves gas extraction efficiency from coal seams. In this paper we report results from simulations using FLAC^3D code to analyze changes in coal displacement and stress after special drill slots were formed. We investigated the mechanism of pressure relief and permeability increase in a high-gas and low-permeability coal seam through the modeling of gas flow. This allows the development of the technology. Slotting across rock layers in the coal seam with a rotary type cutter was then applied in the field. The results show that pressure relief and permeability increases from slotting the coal seam can increase the transport and the fracture of the coal. This expands the range of pressure relief from the drilling and increases the exposed area of the seam. The total quantity of gas extracted from slotted bore holes was three times that seen with ordinary drilling. The concentration of gas extracted from the slotted drills was from two to three times that seen using ordinary drills. The gas flow was stable at 80%. Improved permeability and more efficient gas extraction are the result of the slotting. The roadway development rate is increased by 30–50% after gas drainage. This technology diminishes the lag between longwall production and roadway development and effectively prevents coal and gas outburst, which offers the prospect of broad application.     

在断层发育的煤矿预测适合综采地段的一种新方法

鹤壁大矿二＿１煤层附近的小断层多集中分布于焕层顶底板砂岩厚度的低值区，其主要原因是砂岩薄处比厚处更容易发生断裂，这种规律已在生产中得到了证实。笔者利用此规律为鹤壁六矿后期生产选择了４个适合综采的地段。