沁水盆地山西组煤储层含气性及控制因素分析

依据实测资料,在统计分析研究区３号煤层含气性特征的基础之上,对控气地质机理进行了探讨,总体上来看,研究区甲烷含量较高高及甲烷浓度较大,而含气饱和度偏低。在埋深１０００ｍ以浅,向盆地内部方向以及随煤层埋深加大,甲烷含量,甲烷浓度和含气孢和度具有增大趋势,显示出埋探控气以及次级向斜相对富气的特点,这种特征可以起源于地质历史时期中煤层抬升卸压过程所导致的煤层气解吸扩散作用。因此,进一步查明次级构造的发育     

沁水盆地郑庄区块构造演化与煤层气成藏

基于沁水盆地郑庄区块的构造发育特征,研究了自二叠纪煤系形成以来该区域构造应力场演化,分析了其对煤层气藏的控制作用,包括构造-埋藏史、后期成藏演化及成藏控制因素.研究表明:郑庄地区主要经历了印支期、燕山期、喜马拉雅早期和喜马拉雅晚期—现代4个期次的构造应力场演化.在构造控制下,二叠纪煤层经历了印支期和燕山中—晚期两次成烃作用,特别是燕山中、晚期煤层生气量巨大,是煤层气的主要成藏期.此后,随着地壳持续抬升剥蚀,煤层埋藏不断变浅,并发育了多组封闭性较好的节理.受南东侧的寺头断层控制,煤层埋深处于600～1 200m,为煤层气成藏以来的最浅埋藏,虽然本区二叠系煤层气的成藏时间较早,但保留的煤层气含量大,煤储层厚度大,且煤层埋藏适中.     

Prediction of Coal Seam Methane Enriched Areas Using Seismic Data

All coal mine disasters are dynamic geological phenomenon and affected by many factors. However, locating the enriched areas of CSM （coal seam methane） may be the precondition for the successful prediction of such disasters. Traditional methods of investigating CSM enriched areas use limited data and only consider a few important factors. Their success rate is low and cannot meet practical needs. In this paper, an alternative method is proposed. The procedure is given as follows： 1） fracture attributes derived from azimuth variations of P-wave data in coal seams and wall rocks can be extracted; 2） AVO attributes, such as the intercept P and gradient G parameters can be extracted from different azimuths from 3D seismic data; 3） seismic cubes can be inverted and the relative attributes of impedance cubes can be extracted; 4） using a GIS platform, multi-source information can be obtained and analyzed; these include fracture attributes of coal seams and wall rocks, the thickness of coal seams, the distribution of faults and structures, the depth of coal seams, the inclination and exposure of coal seams and the coal rank. Through this processing procedure, methane enriched areas can be systematically detected.     

吐哈盆地沙尔湖地区煤层气钻完井适用技术探讨

在剖析美国圣胡安盆地煤层气空气钻井、裸眼洞穴完井技术及优势的基础上,确定了低煤阶煤层气钻井及裸眼洞穴完井的煤储层条件等,并以吐哈盆地沙尔湖地区低煤阶煤层气为主要研究对象,利用类比法及地质统计法,具体分析了吐哈盆地沙尔湖地区的煤储层厚度、含气量、渗透率、井壁稳定性及储层压力条件等．研究表明,沙尔湖地区煤层厚度大,储层物性好,井壁稳定性好,可采用低成本空气钻井及裸眼完井技术提高钻井效率,保护煤储层,提高煤层气采收率．     

Reservoir reconstruction technologies for coalbed methane recovery in deep and multiple seams

Multiple coal seams widely develop in the deep Chinese coal-bearing strata. Ground in situ stress and coal seam gas pressure increase continuously with the increase of the mining depth, and coal and gas outburst disasters become increasingly severe. When the coal is very deep, the gas content and pressure will elevate and thus coal seams tends to outburst-prone seams. The safety and economics of exploited firstmined coal seams are tremendously restricted. Meanwhile, the multiple seams occurrence conditions resulted in different methane pressure systems in the coal-bearing strata, which made the reservoir reconstruction of coal difficult. Given the characteristics of low saturation, low permeability, strong anisotropy and soft coal of Chinese coal seams, a single hydraulic fracturing surface well for reservoir reconstruction to pre-drain the coalbed methane(CBM) of multiple seams concurrently under the different gas pressure systems has not yet gained any breakthroughs. Based on analyses of the main features of deep CBM reservoirs in China, current gas control methods and the existing challenges in deep and multiple seams, we proposed a new technology for deep CBM reservoir reconstruction to realize simultaneous high-efficiency coal mining and gas extraction. In particular, we determined the first-mined seam according to the principles of effectiveness and economics, and used hydraulic fracturing surface well to reconstruct the first-mined seam which enlarges the selection range of the first-mined seam. During the process of mining first-mined seam, adjacent coal seams could be reconstructed under the mining effect which promoted high-efficiency pressure relief gas extraction by using spatial and comprehensive gas drainage methods(combination of underground and ground CBM extraction methods). A typical integrated reservoir reconstruction technology, ‘‘One well for triple use", was detailed introduced and successfully applied in the Luling coal mine. The application showed that the proposed technology could effectively promote coal mining safety and simultaneously high-efficiency gas extraction.     

新兴煤矿22号煤层瓦斯赋存影响因素分析

为了研究新兴煤矿地质构造对瓦斯赋存的控制作用,以瓦斯地质原理为基础,采用瓦斯赋存构造逐级控制理论方法,以煤层厚度、煤层埋藏深度、断层性质和凝灰岩厚度等影响因素为依托,建立了煤层瓦斯与地质影响因素相互关系的多元回归数学模型,并得出与实际值比较接近的预测值.研究结果表明:煤层埋藏深度是影响新兴煤矿22号煤层瓦斯含量的主控因素;上覆凝灰岩对煤层瓦斯保存起到了积极作用;NW-NWW向断层附近容易发生煤与瓦斯动力现象.     

新安煤田正村井田二叠系煤岩层对比

煤岩层对比工作对于煤田地质勘探、储量计算以及煤炭资源的开发利用都具有极其重要的意义,它是研究含煤地层层序、煤田地质构造、煤层厚度变化、煤层赋存规律的基础工作,是煤田地质勘探工作的主要任务之一.本文采用标志层法、层间距法、煤质特征分析法和测井响应,对本区的主要含煤层段二叠系山西组、上下石盒子组进行了系统的划分和对比,准确确定了主要可采煤层二1煤层和局部可采煤层二2煤层、七2煤层的层位,并对这些煤层的空间展布进行了对比,这一煤岩层对比方案已为煤田勘探和煤矿开采的揭露所证实.     

古汉山井田煤层气赋存特征

以焦作煤田古汉山井田为研究区,通过定性分析与定量研究,探讨了煤层埋深、顶底板岩性、煤层埋深以及地质构造等因素对煤层含气性的控制;通过数理统计的方法,得出了埋深、有效埋藏深度以及煤厚与煤层含气量的回归方程,并对回归方程进行了显著性检验.研究结果表明,煤厚、断裂构造以及埋深是影响古汉山井田煤层气赋存特征的主要因素,并表现为:①随着煤厚的增加,含气量线形增大.②随着埋深和有效埋藏深度的增加,含气量先是急剧增大,到了一定阶段后,增大趋势变慢,之间具有对数正相关关系.③在断层尖灭端,含气量大,断裂带内含气量小;正断层的下降盘的含气量大于上升盘,同一正断层的上升盘附近,距离断层面越远,含气量越大.煤层的顶板岩性对含气量有一定的影响,但不是引起井田内煤层含气量变化的主控因素.     

Prediction of geotemperatures in coal-bearing strata and implications for coal bed methane accumulation in the Bide-Santang basin,western Guizhou,China

The geothermal fields of coal-bearing strata have become a key topic in geological research into coal and coal bed methane(CBM). Based on temperature data from 135 boreholes that penetrate the Upper Permian coal-bearing strata in the Bide-Santang basin, western Guizhou, the precisions of geothermal predictions made using a geothermal gradient model and a gray sequence GM(1,1) model are analyzed and compared. The results indicate that the gray sequence GM(1,1) model is more appropriate for the prediction of geothermal fields. The GM(1,1) model is used to predict the geothermal field at three levels with depths of 500, 1000, and 1500 m, as well as within the No. 6, No. 16, and No. 27 coal seams. The results indicate that the geotemperatures of the 500 m depth level are between 21.0 and 30.0 °C, indicating no heat damage; the geotemperatures of the 1000 m depth level are between 29.4 and 44.7 °C,indicating the first level of heat damage; and the geotemperatures of the 1500 m depth level are between35.6 and 63.4 °C, indicating the second level of heat damage. The CBM contents are positively correlated with the geotemperatures of the coal seams. The target area for CBM development is identified.     

等温吸附曲线方法在煤层气可采资源量估算中的应用

在缺乏煤层气井生产资料的情况下，为了合理利用我国煤田地质勘探中煤层气解吸法所测的煤层气含量，使其计算的煤层气资源量与可采资源量更为接近，根据煤层气解吸特征，煤储层等温吸附特征，通过计算解吸系数，求取煤层气的解吸率．利用等温吸附曲线与煤层气临界解吸压力的关系，估算出煤层气临界解吸压力，并结合煤层气井的枯竭压力，估算出煤层气采收率，进而获得煤层气可采资源量．结果表明，残余气在煤层气开采时基本上是不可能获得的，另外由于生产技术的原因，参考国外煤层气实际生产情况，井深结构所能达到的最低储层压力之下的煤层气也基本上不能被采出．因此通过解吸系数法校正、等温吸附曲线法校正后，计算的煤层气资源量更能反映煤层气的可采潜力．     

Dynamic development characteristics of amounts of gas and levels of pressure in the Pan-1 coal mine of Huainan

The Pan-1 coal mine located in Huainan municipality, Anhui province, is abundant in coal resources. In order to discover the natural conditions of gas in its coal seams, we inverted the burial history of these coal seams using the software of Easy%Ro method and simulated the development process of gas volumes and pressure of the major coal seams using CBMHistory Simulation Software. Our analysis shows that the devolution of gas volumes and levels of pressure can be divided into four stages: I.e., a biogas stage (P1-P3), a pyrolysis gas stage (T1-T2), an active gas enrichment stage (T3-K1) and a gas dissipating stage (K2-present). Cur-rently, the average amounts of gas and gas pressure in coal seams Nos. 13-1,11-2 and 8 of the Pan-1 coal mine are 8.18 m3/t and 2.20 Mpa; 3.89 m3/t and 2.47 Mpa and 6.35 m3/t and 2.89 Mpa, respectively. This agrees very well with current mining data.     

Fracture evolution and pressure relief gas drainage from distant protected coal seams under an extremely thick key stratum

When an extremely thick rock bed exists above a protected coal seam in the bending zone given the condition of a mining protective seam, this extremely thick rock bed controls the movement of the entire overlying stratum. This extremely thick rock bed, called a "main key stratum", will not subside nor break for a long time, causing lower fractures and bed separations not to close and gas can migrate to the bed separation areas along the fractures. These bed separations become gas enrichment areas. By analyzing the rule of fracture evolution and gas migration under the main key stratum after the deep protective coal seam has been mined, we propose a new gas drainage method which uses bore holes, drilled through rock and coal seams at great depths for draining pressure relief gas. In this method, the bores are located at a high level suction roadway (we can also drill them in the drilling field located high in an air gateway). Given the practice in the Halzi mine, the gas drainage rate can reach 73% in the middie coal group, with a gas drainage radius over 100 m.     

石门沟煤矿3号煤层瓦斯赋存规律探究

煤层瓦斯质量体积（含量）是煤层瓦斯主要参数之一,是矿井进行瓦斯涌出量预测、煤与瓦斯突出预测和瓦斯抽放设计的重要依据.只有摸清矿井瓦斯赋存规律,才能对采掘面瓦斯抽放制定合理的技术措施.为避免石门沟煤矿瓦斯治理的盲目性,笔者通过分析煤层瓦斯质量体积与埋藏深度的关系,并结合矿井地质构造,研究了煤层瓦斯赋存规律,总结得出石门沟煤矿3号煤层瓦斯质量体积受地质构造控制,在远离地质构造区域,瓦斯质量体积与埋藏深度呈正相关,并推出其关系式,为矿井瓦斯治理提供可靠数据.     

石门沟煤矿3号煤层瓦斯赋存规律探究

煤层瓦斯质量体积(含量)是煤层瓦斯主要参数之一,是矿井进行瓦斯涌出量预测、煤与瓦斯突出预测和瓦斯抽放设计的重要依据.只有摸清矿井瓦斯赋存规律,才能对采掘面瓦斯抽放制定合理的技术措施.为避免石门沟煤矿瓦斯治理的盲目性,笔者通过分析煤层瓦斯质量体积与埋藏深度的关系,并结合矿井地质构造,研究了煤层瓦斯赋存规律,总结得出石门沟煤矿3号煤层瓦斯质量体积受地质构造控制,在远离地质构造区域,瓦斯质量体积与埋藏深度呈正相关,并推出其关系式,为矿井瓦斯治理提供可靠数据.     

Prediction of coal structure using particle size characteristics of coalbed methane well cuttings

Severely deformed coal seams barely deliver satisfactory gas production. This research was undertaken to develop a new method to predict the positions of deformed coals for a horizontal CBM well. Firstly, the drilling cuttings of different structure coals were collected from a coal mine and compared. In light of the varying cuttings characteristics for different structure coals, the coal structure of the horizontally drilled coal seam was predicted. And the feasibility of this prediction method was discussed. The result shows that exogenetic fractures have an important influence on the deformation of coal seams. The hardness coefficient of coal decreases with the deformation degree in the order of primary structural, cataclastic and fragmented coal. And the expanding-ratio of gas drainage holes and the average particle size of cuttings increase with the increase of the deformation degree. The particle size distribution of coal cuttings for the three types of coals is distinctive from each other. Based on the particle size distribution of cuttings from X-2 well in a coal seam, six sections of fragmented coal which are unsuitable for perforating are predicted. This method may benefit the optimization of perforation and fracturing of a horizontal CBM well in the study area.     

地空时间域电磁系统在陕西神木地区煤矿采空区勘查中的应用

为实现陕西神木地区哈拉沟煤矿周边小煤矿采空区的精确定位,采用地空时间域电磁系统在哈拉沟煤矿三盘区附近原小煤矿可能开采范围开展勘查工作。利用电源车集成的大功率地面发射系统,搭配基于旋翼无人机的单分量地空电磁信号接收系统,共采集23条测线的电磁数据。经数据处理后,得到勘查区内地下视电阻率与视深度的高分辨率成像剖面,结合已知钻孔资料综合分析,推测勘查区对应地下煤层位置的低阻带是由煤层积水采空区造成,据此共圈定了8处疑似积水采空区,其中5处为相对低阻异常区域,分布于勘查区中南部、中部以及东北部区域。本次探测工作验证了地空时间域电磁系统在煤矿采空区勘查中的有效性,能够为工作面合理布置和采空区治理等提供可靠的地质信息。     

焦作矿区山西组二1煤层含气量的控制因素探讨

分析了焦作矿区煤层气含量的分布规律 ;探讨了断块构造、煤层埋深、上覆岩层厚度等对煤层气的控制作用 .结果表明 :焦作矿区山西组二1煤煤层气含量较高 ,最高达 3 2 .7m3 /t(daf) ,平均为 1 6 .7m3 /t(daf) ;由于煤变质及其演化、煤层的有效埋藏深度、抬升剥蚀作用和地质构造等因素对煤储层特性产生显著的影响 ,使本区煤层气含量分布具有明显的规律性 ,从西部断块至东部断块煤层气含量由高到低变化 ,且各断块内由浅部向深部逐渐增高 .     

重庆松藻矿区打通一矿M_8煤层瓦斯赋存地质规律

以重庆松藻矿区打通一矿为研究区,基于瓦斯地质理论,探讨了地质构造、煤厚、埋深、有效埋深以及顶底板岩性等地质因素对主采煤层M8煤层中瓦斯赋存的影响规律.通过数理统计的方法构建了各因素与瓦斯含量的回归方程,并对其进行了显著性检验.研究结果表明,煤厚、埋深等是影响打通一矿M8煤层瓦斯含量分布的主控因素,褶皱构造对瓦斯局部富集具有重要影响,而顶底板区域内岩性比较稳定,有利于瓦斯的保存,但不是引起含气性变化的主要因素.     

乡宁矿区煤储层地质特征研究

煤层气富集成藏受煤储层地质特征的制约。通过对大量实验测试数据的分析与对比,研究了乡宁矿区煤层气成藏基础地质特征,主要包括煤储层发育特征、煤岩学特征、煤化学与工艺特征及煤级与煤相特征等。结果表明,本区主要煤层煤空间展布稳定、累计厚度大、煤质好、热演化程度高,具备煤层气成藏的基础条件。     

应用XPS研究镜煤中有机硫的存在形态

应用 XPS方法研究了鄂尔多斯盆地西北缘乌达矿区 9煤层、1 2煤层和 1 5煤层手选镜煤的有机硫赋存状态 .结果表明 ,煤中有机硫的存在形式是多样的 ,这主要取决于成煤母质、沉积环境和泥炭堆积后的成岩变化 .在泥炭堆积过程中 ,由于菌类和藻类低等生源的大量输入 ,是导致9煤层有机硫以噻吩型 ( 5 0 .67% )为主的主要原因 ;从 9煤层 ( Ro,ran=0 .96% )到 1 5煤层 ( Ro,ran=1 .0 9% )随着煤级增高 ,有机硫表现出以噻吩型为主的趋势 ;1 5煤层含有较高的硫砜型硫( 8.42 % ) ,这可能与该煤层中壳质组含量稍高 (φ(壳质组 ) =1 .6% )有关