共查询到20条相似文献，搜索用时 15 毫秒
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Different parameters obtained through geophysical borehole logging using self potential, resistivity, gamma–gamma, neutron, natural gamma, and acoustic tools, help in the identification of strata and estimation of the physical, electrical, and acoustical properties of the subsurface lithology. In the coal mining industry, currently, the main application for the logs is to determine coal seam depth, thickness together with coal seam quality, qualitatively. Gamma and resistivity logging in seven boreholes at the Phulbari Coal Basin show high resistivity value and low gamma count rate data in coal seams than the interbeds. An attempt has been made to identify and characterize Gondwana coal seams to a limited extent of seam depth, thickness, and quality in seven boreholes together with draw relationship between resistivity, gamma count rate, and ash content of coal at the Phulbari Coal Basin of Bangladesh. 相似文献
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贵州省金沙煤田龙潭组岩煤层测井对比方法 总被引：2，自引：0，他引：2
龙潭组是金沙井田的主要含煤地层，含煤达12~15层，其中7、8、9、11、12五层煤较稳定，为主要可采煤层。根据测井物性曲线与地质岩心的对比分析，总结出该组煤岩层的共有测井物性规律：低密度、中低电阻率、较高中子孔隙度和较低的纵波速度，以及其特有规律如：5、6、7、8、9煤层的低自然伽马，11、12煤层较高的自然伽马等特征。结合煤层测井曲线形态特征及其与顶、底板以及和煤层上、下标志层间组合关系，进行了全煤系地层的对比，揭示了该井田煤层的分岔、合并、冲刷、沉缺、煤层厚度等变化规律。 相似文献
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煤体结构类型与煤储层孔裂隙特征密切相关,对煤层气开采具有重要意义。以韩城矿区为例,通过对区内的参数井取心样品分析,把煤体结构分为块煤(I类)、块粉煤(II类)、粉煤(III类)。对区内3号、5号和11号煤层的深侧向电阻率测井、井径测井和自然伽玛测井曲线特征进行对比,归纳了各煤体结构的测井曲线组合特征:I和III类煤电阻率曲线和自然伽玛曲线为平滑的箱型或钟形,II类煤则为波动的箱形;II和III类煤扩径严重,且II类煤差异扩径明显。据此,提出了一种利用电阻率测井、井径测井和自然伽玛测井等测井曲线组合识别煤体结构的方法,并利用这种方法准确识别出同一煤层不同煤体结构的分层。 相似文献
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Joyjit Dey Souvik Sen Surjyendu Bhattacharjee 《Journal of the Geological Society of India》2018,92(1):36-44
North Karanpura coal field is the western most marginal coal bearing segment of east-west trending Damodar valley basin. It consists of middle Permian Barakar Formation with sandstone, siltstone, coal and shale being the dominant lithofacies, deposited in a fluvial meandering environment, giving rise to repetitive fining upwards cycles. Study of geophysical logs, the drilled core holes were used to identify lithofacies, correlate coal seams with splitmerge behavior; which has been used to understand lateral and vertical facies disposition. Geophysical logs have been employed to compute various coal assay parameters–ash, fixed carbon, moisture, volatile content, cleat porosity, vitrinite reflectance seam wise. Study of log based coal assay parameters, calibrated with lab based values depicts lateral coal quality variation, i.e. decreasing ash content, higher fixed carbon from east to west, which can be a great proxy for future development of field or mine planning. 相似文献
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SHAO Longyi WEN He GAO Xiangyu Baruch SPIRO WANG Xuetian YAN Zhiming David J. LARGE 《《地质学报》英文版》2022,96(6):1830-1841
Individual coal seams formed in paleo-peatlands represent sustained periods of terrestrial carbon accumulation and a key environmental indicator attributed to this record is the rate of carbon accumulation. Determining the rate of carbon accumulation requires a measure of time contained within the coal. This study aimed to determine this rate via the identification of Milankovitch orbital cycles in the coals. The geophysical log is an ideal paleoclimate proxy and has been widely used in the study of sedimentary records using spectral analysis. Spectral analyses of geophysical log from thick coal seams can be used to identify the Milankovitch cycles and to calculate the period of the coal deposition. By considering the carbon loss during coalification, the long-term average carbon accumulation rate and net primary productivity (NPP) of paleo-peatlands in coal seams can be obtained. This review paper presents the procedures of analysis, assessment of results and interpretation of geophysical logs in determining the NPP of paleo-peatlands. 相似文献
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本文应用沉积学与测井学理论,对山东聊城煤矿区太原组的沉积环境进行了研究,认为太原组是以陆源碎屑潮坪及泻湖为主体的海退沉积与潮下带海进沉积所组成的多施回沉积体系,主采煤层M9,M10形成于泻湖泥遄沼泽化环境。在分析M9、M10煤聚煤特点的基础上,运用灰色系统理论,建立了M9、M10煤GM（1,1）灰色数学横型,并对煤厚进行了灰色预测。 相似文献
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青海省北大滩地区煤炭勘查工作的关键是沉积期的聚煤环境和沉积前后构造作用对煤层赋存的控制作用。为明确柴北缘东部北大滩地区石门沟组的控煤因素,有效指导该含煤区的煤炭勘查工作,基于野外露头、钻孔、地球物理勘探等地质资料,在分析北大滩地区石门沟组聚煤环境和构造作用的基础上,从聚煤环境、古隆起和断裂、向斜等方面深入探讨了石门沟组的控煤因素。其中,扇三角洲平原分流河道间的泥炭沼泽和滨湖环境的滨湖沼泽是有利的成煤环境,控制着煤层横向发育、分布特征;古隆起控制着有利聚煤区和煤层分布区;北大滩向斜内部次级背斜和逆断层的上盘控制着煤层埋藏深度,煤层埋藏浅降低了后期煤炭勘查的难度。 相似文献
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为指导豫东地区煤矿合理部署、高效生产,基于大量钻井和测试资料的综合分析和对比研究,探讨了豫东地区岩浆活动的基本特征及其对煤层结构和煤质的影响。研究结果表明:燕山中晚期的岩浆活动对豫东地区的煤层结构和煤层连续性造成影响,导致煤层变薄、分叉、尖灭和吞噬;同时,岩浆活动导致本区煤层变质程度普遍增高,煤质参数发生变化。煤层的原始赋存状态、岩浆侵入的初始温度、侵入岩体的厚度、岩浆侵入煤层的方式、岩体离煤层的距离、围岩和岩体上覆地层的岩性等是影响煤层结构和煤变质程度的主要控制因素。 相似文献
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青藏高原构造复杂,岩层、煤层倾角较陡,过去物探方法找煤效果不够理想。近几年在鱼卡煤田云雾山地区、小红山地区、羊水河地区、天峻苏里地区及海北门源盆地等地利用可控源音频大地电磁测深（CSAMT）进行勘探,有效解决了高原冻土带高阻屏蔽层下第四系厚度、含煤岩系侏罗系基底深度、构造及基底起伏形态等地质问题。为钻探的布设提供了物探依据。 相似文献
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新疆沙尔湖煤田煤层特征及对比 总被引：1，自引：0，他引：1
沙尔湖煤田含煤地层为中侏罗统西山窑组,根据岩性特征、含煤性以及其组合特征,将西山窑组分为上、中、下三段,可采煤层均分布在中段,煤层层数多,厚度变化较大,可采煤层6～27层,可采煤层总厚114.35～139.90m,根据各煤层之间的沉积间距及其与上、下岩层的旋回韵律,又将其划分为Ⅰ、Ⅱ、Ⅲ煤组。以大量地质资料为基础,总结了主要含煤层段的岩相组合特点,揭示了各煤层间的差异及组合特征,利用有效的对比方法,特别是数字测井在煤层对比中的应用,对可采煤层进行系统对比分析,对煤层对比的可靠性进行评价,保证了层位对比的正确可靠,并解决了勘查工作中终孔层位难以确定的问题,为正确划分煤系地层、准确估算煤炭资源量提供了可靠依据。 相似文献
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煤层流变及其与煤矿瓦斯突出的关系—以淮北海孜煤矿为例 总被引：16，自引：0，他引：16
复杂地质条件下煤层受层间滑动作用容易发生流变。本文以淮北海孜煤矿为例，详细分析了煤层流变所引起的煤层形变宏观、微观及构造煤特征，总结了煤层流变构造发育的规律。煤层流变引起煤层形态、煤厚及煤体结构的变化，并形成各种构造煤。利用煤镜质组光率体各向异性进行了应力、有限应变分析，探讨了煤层流变机制是以剪切为主，伴有挤压的后期构造作用。海孜煤矿构造活动具有多期性，但煤层受力的主要方向始终为NW－SE向，这与煤层发生流变形成总体NE－SW向增厚变薄带的展布方向是一致的。已采区的煤层流变有：韧性流变、脆性流变及韧脆性流变。煤层流变引起的厚度变化和煤体结构的破坏是造成煤矿瓦斯突出的主要因素。 相似文献
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为研究榆神矿区最上可采煤层赋存及开采对萨拉乌苏组含水层危害程度,依次分析了榆神矿区最上可采煤层赋存特征、最上可采煤层与上覆主要含（隔）水层空间分布规律及组合类型,基于基载比和采高的最上可采煤层覆岩导水裂隙带发育规律、煤层开采对萨拉乌苏组含水层危害程度,将榆神矿区开采受危害程度分为4类:自然保水区、保水采煤区（影响大区和影响小区）、采煤失水区及采煤无水区。结果表明:受构造及剥蚀作用影响,榆神矿区最上可采煤层及上覆基岩呈差异剥蚀,煤露头线从SE向NW呈阶梯状分布,最上可采煤层上覆基岩由NW到SE方向逐渐变薄。榆神矿区西部（三、四期）最上可采煤层开采后对萨拉乌苏组含水层危害程度小或没影响;榆神矿区东部（一、二期）最上可采煤层开采后对萨拉乌苏组含水层危害程度大。 相似文献
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通过对平山湖地区11口井的测井资料进行分析,初步掌握了该区含煤岩层的地球物理特性及其在视电阻率、密度、自然伽马、声波时差、自然电位等测井曲线上的响应特征。总结出一套适合该地区的测井方法,如各种测井参数的数据计算方法与曲线处理技巧,为该类地区使用TYSC-3Q测井仪器进行测井提供了参考依据。针对该地区煤层具有中高阻、低密度、低放射性、高时差、弱自然电位的物性特征,以多个实例介绍了煤层在不同测井参数曲线上的识别方法及定量解释原则。 相似文献
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N. Vinayachandran A. C. Narayana K. Md. Najeeb P. Narendra 《Journal of the Geological Society of India》2013,81(2):183-191
Kuttanad near the western coast of Kerala is a low lying area below mean sea level. The hydrogeological scenario in this wet land dominated tract, known as kole lands, was investigated by using the lithological and geophysical data generated under the R&D exploration programme of Central Ground Water Board (CGWB) during the year 2000, as also other related data generated till the year 2009. The hydrogeology of the tract is complex, and the presence of carbonaceous and organic matter in the soil and sub-soil influences the geochemical and geo-electric characteristics of the sub-surface geological formations as reflected by SP and resistivity logs. The lithologs and geophysical logs of bore wells were used to define the aquifer geometry. While the lateral and vertical variations of the aquifer systems identified were high, the bottom aquifer was relatively brackish over a large area. The gamma log behavior in these granular zones is anomalous and misguiding in nature. The radioactivities recorded against clay horizons were in the range of 130 to 200cps and in the granular zones 150 to 350 cps. The presence of monazite bearing sands at certain depths was responsible for anomalously high gamma counts against granular zones. The water quality in the granular zones was inferred from the electrical logs. The depth of occurrence of high radiation sand beds was also demarcated. 相似文献
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大同侏罗纪煤田无线电波坑道透视特征 总被引：4，自引：2，他引：2
介绍了大同侏罗纪煤田煤系地球物理特征和煤层中地质小构造的电磁波透视特征,说明在大同侏罗纪煤田采用无线电波坑道透视技术,能够有效地探测出煤层中的各种地质小构造,较好地指导综采生产。 相似文献
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杭东普查区煤层产状平缓,构造简单,但由于含煤地层为陆相沉积,煤层层数多、厚度、间距变化大,沉积岩相变化快、大范围内缺乏稳定的对比标志层,因此煤岩层对比是本区勘查需要重点解决的难题。通过对比杭东普查区与邻区200余孔的测井资料,分析煤岩层在各种测井曲线的异常特征与异常组合规律,确定了对煤岩层对比有重大意义的标志层,如延长组与上覆延安组的典型视电阻率异常分界;延安组在高视电阻率曲线上的“树杆”状凸起特征;安定组视电阻率曲线近直线的低值形态;4-1煤在视电阻率曲线上呈现出的“斜坡”状或“刀”状高异常,以及在自然伽玛曲线上的“凹坑”特征;侏罗系中统直罗组的高伽马异常,等等。这些典型特征保证了该区煤岩层对比可靠性,为提交优质地质勘查报告发挥了重要作用。 相似文献