【作者】 陈强；

【导师】 张贵宾；

【作者基本信息】 中国地质大学（北京） ， 地球探测与信息技术， 2011， 博士

【摘要】 我国高瓦斯矿井众多,影响瓦斯富集和突出危险区分布的主控因素不一。开展基于特定主控因素,面向瓦斯富集性预测的地震技术研究是煤田地震勘探面临的新课题。鉴于目前高瓦斯矿井采区三维地震勘探中普遍存在的采集、处理和解释方法的盲目性和技术应用水平低等问题,本文依托山西阳煤集团“地震反演技术预测煤矿瓦斯富集区的研究与应用”项目,针对上述问题进行了系统性应用研究。从影响石港矿井瓦斯富集区分布的主控因素(挠曲构造)出发,采用三维正演模拟方法计算分析了适合研究区实际条件的三维地震观测类型;通过叠前和叠后偏移方法处理成果的对比讨论,明确了叠前处理的技术优势和必要性;应用叠前弹性阻抗反演技术和频谱分解等地震新技术预测了目标煤层瓦斯富集和突出危险区的分布范围。主要研究结论如下:1、分析和研究了石港矿井构造演化历史、煤系地层的沉积环境以及煤储层的厚度、煤级、煤体结构、含气性等影响瓦斯富集的众多地质因素,获得了挠曲构造带是影响本区瓦斯富集性的主控因素这一明确结论。2、建立了研究区复杂地表和挠曲实际赋存形态的三维模型,利用常速度梯度三维射线追踪法,模拟了与瓦斯富集性密切相关的煤层反射波高频能量在不同采集方向的宽窄方位观测系统下,多种CRP面元属性的变化特征,明确提出了宽方位观测的必要性。3、对比分析了叠前和叠后时间偏移两种方法的实际处理效果和解释成果,认为叠前时间偏移能够有效提高挠曲构造的定性、定量解释水平以及陷落柱等影响瓦斯局部富集区分布的小规模构造和地质异常体的识别率。4、首次提出并利用最大正、负曲率属性研究了挠曲构造带的展布和变形特点,并综合电阻率拟声波特征参数反演方法获得的构造软煤预测成果,确定挠曲构造基本控制了研究区构造煤的发育程度和范围。5、首次将三维叠前弹性阻抗(EI)反演技术应用于高瓦斯矿井区域性瓦斯富集范围预测。认为本区纵横波速度比与瓦斯含量呈显著负线性相关;预测结果整体上符合瓦斯实测值变化趋势,并与构造煤和挠曲构造的分布范围具有良好的对应关系。在煤田声波测井资料缺乏的情况下,本次研究采用的两个角度的弹性阻抗反演方法是一次有益的尝试。6、首次采用小波变换的谱分解技术,研究了突出危险煤体高频反射能量相对强衰减响应特征,半定量地分析和圈定了研究区煤与瓦斯突出危险区范围。预测成果基本符合瓦斯地质规律,具有一定的指导意义。更多还原

【Abstract】 China has a mass of high gas coal mines and there are various main control factors that determine the gas enrichment area and the distribution of highly coal and gas outburst zone. Therefore, it is important to study on the application of 3D seismic prospecting technology to the predication of gas enrichment degree based on specific main control factors.At present, there are many problems in applying 3D seismic prospecting technology to the exploration of high gas coal mines, such as lack of means in acquisition, processing and interpretation work, lack of a clear objective and poor skill level on the part of new technology application. Aiming at the above mentioned problems and based on a research project sponsored by Yang Quan Coal Industry( Group ) Co.,LTD, namely“the Study and Application of Seismic Inversion Technology to Gas Enrichment Area Prediction”, the paper made a systematic study on the topic. It analyzed the main control factors (flexural structure) affecting the distribution of high gas enrichment area in the coal mine in question and adopted a 3D forward modeling method to figure out the appropriate 3D seismic observation pattern for the specific condition of the area; Through a contrastive analysis on the results of time-domain pre-stack versus post-stack migratation, the necessity and advantage about pre-stack migratation is cleared; employing the new technology of pre-stack Elastic impendence inversion and Spectral Decomposition, the paper also predicted the gas enrichment degree of the target coal seam as well as the distribution of highly dangerous zone. The following are the main conclusions:1. Based on analysis of many geologic factors, such as structure evolution history and development characteristics, coal seam formation depositional environment, and the distribution features such as coal thickness, rank, coal body, gas bearing, it is concluded in the paper that the flexural structure is the main control factor affecting the distribution of gas enrichment area, coal and gas outburst region in Shigang Coal Mine.2. Establishing the 3D model of complex undulating surface and underground flexural structures by ray tracing of 3D constant velocity gradient, it conducted forward modeling to study variation characteristics of several CRP bin attributes about the high frequency energy resulting from the wide and thin observation azimuthal systems with different observation direction. The necessity of adopting the wide-azimuthral observation method is pointed out in the paper.3. Comparing the actual processing results and the interpretation results from pre-stack and post-stack migratation respectively, it is proved in the paper that pre-stack migratation is more effective in qualitative and quantitative interpretation of complex structure as well as improving the recognition rate of small structure of collapse column.4. Using post-stack multi-well constrained inversion method, the thickness variation tendency of the No.15 coal seam was predicted. It is proposed for the first time to use the maximum positive and negative curvature attributes to analyze the planar distribution and deformation features of flexural zone. Combined with the predicted result of the tectonized coal body achieved through the resistivity pseudo-acoustic characteristic parameters inversion method, it is concluded in the paper that the distribution range of tectonized coal body is determined by the flexural structure.5. For the first time the 3D seismic prestack elastic impendence inversion (EI) technology is applied to predicting the gas enrichment range in high gas mine. Vp/Vs ratio shows clear negative linear correlation with gas bearing. In general, the predicted results is consistent with the measured gas bearing values and fits in with the gas enrichment ranges in high gas emission zone. Considering the lack of acoustic logging data, it is a good attempt to base the EI inversion method in this study on two angle-stack data.6. It is the first attempt to apply spectral decomposition technology with wavelet transform algorithm to study the coal and gas outburst region. The study not only found the relative high attenuation response feature about high frequency reflection energy in gas outburst coal body, it also completed a semi-quantitative analysis and determined the distribution of coal and gas outburst region. Since the predicted results on the whole accord with the gas geologic law, it may offer some useful guidance to underground mining work.更多还原