煤系灰岩地震波有限差分模拟及响应特征分析.pdf

硕士学位论文 煤系灰岩地震波有限差分模拟 及响应特征分析 Seismic Wave Finite Difference Modeling of Coalfield Limestone and Analysis on Response Characteristics 作 者张 敏 导 师董守华 教授 中国矿业大学 二○一七年六月 学位论文使用授权声明 学位论文使用授权声明 本人完全了解中国矿业大学有关保留、使用学位论文的规定，同意本人所撰 写的学位论文的使用授权按照学校的管理规定处理 作为申请学位的条件之一， 学位论文著作权拥有者须授权所在学校拥有学位 论文的部分使用权，即①学校档案馆和图书馆有权保留学位论文的纸质版和电 子版，可以使用影印、缩印或扫描等复制手段保存和汇编学位论文；②为教学和 科研目的，学校档案馆和图书馆可以将公开的学位论文作为资料在档案馆、图书 馆等场所或在校园网上供校内师生阅读、浏览。另外，根据有关法规，同意中国 国家图书馆保存研究生学位论文。 （保密的学位论文在解密后适用本授权书） 。 作者签名 导师签名 年 月 日 年 月 日 中图分类号 P631 学校代码 10290 UDC 密 级 公开 中国矿业大学 硕士学位论文 煤系灰岩地震波有限差分模拟 及响应特征分析 Seismic Wave Finite Difference Modeling of Coalfield Limestone and Analysis on Response Characteristics 作 者 张敏 导 师 董守华 申请学位 工学硕士 培养单位 资源与地球科学学院 学科专业 地球探测与信息技术 研究方向 应用地球物理 答辩委员会主席 于景邨 评 阅 人 二○一七年六月 致谢 致谢 感谢我的导师董守华教授，本论文是在导师的关怀和指导下才得以完成。导 师在从论文选题到论文撰写过程中给予了细心的指导和修改， 严格把关从而保证 了本文的完成进度和质量。感谢导师在学习、生活以及工作中给予的不断关心支 持和理解，在论文遇到频颈和没有头绪时，导师给予了我支持和帮助，从而顺利 克服困难。在这短短的三年时间里，我从导师那里不仅学到了物探专业知识，还 学到了导师的严谨治学、谦逊以及对科学追求的实事求是态度。在此我表示对导 师的衷心感谢。 同时感谢中国矿业大学资源与地球科学学院应用地球物理研究所各位老师 的支持和帮助，物探知识博大精深，他们都以独特的角度积极向我解释和指导， 使我能更全面地理解和学习。 感谢 A502 课题组的祁雪梅副教授、 黄亚平博士、 吴海波博士、 陈贵武博士、 魏名地硕士以及杨文强硕士在平时学习和生活中给予的帮助与支持， 通过与大家 的不断交流使我不断进步。 衷心的感谢父母对我的支持，他们的支持是我前进的动力。感谢引文文献的 作者们，感谢在我成长过程中遇到的人。最后感谢在百忙之中评审论文的各位专 家。 I 摘 要 摘 要 煤矿生产伴随着矿井水害的威胁，严重地影响煤矿安全生产，而煤层底板含 水层主要是石炭系和奥陶系灰岩，其中奥陶系灰岩的富水性更强。本文基于岩石 物理基本理论建立煤系灰岩饱水以及变孔隙度饱水岩石物理模型， 进行弹性波有 限差分正演模拟，以此来分析煤系灰岩饱水与变孔隙度饱水的地震响应特征。 有限差分法已经被广泛应用到地震弹性波数值模拟中， 其中有限差分系数决 定着数值模拟精度，本文采用果蝇优化智能算法，将声波方程空间域频散关系绝 对误差最小化，获取其有限差分系数，经过与泰勒级数展开法作对比分析，结果 表明果蝇优化算法压制数值频散能力更强， 并将其拓展到基于递归积分完全匹配 层吸收（RIPML）法的一阶速度-应力方程中，进行煤系灰岩数值模拟。 采用超声 PS 波综合测试仪， 对灰岩岩样在常温条件进行单轴和三轴应力加 载测试实验，精确测量岩样纵横波速度，应用自相容近似模型进行饱水以及变孔 隙度灰岩饱水模量的计算， 建立煤系灰岩初始模型与饱水变孔隙度岩石物理模型。 进行地震有限差分方程正演模拟，经过水平叠加处理，分析对比了煤系灰岩 初始模型饱水与孔隙度为 5、8、10时饱含水模型的地震波特征，模拟结果 表明，韵律型煤系灰岩与砂泥岩薄互层形成的反射波为复合波，且煤系灰岩与围 岩砂泥岩波阻抗差越大，则在地震振幅响应上显示振幅变大，反之则是振幅逐渐 减小。由于实际地层构造复杂，所以还需要对复杂地质条件下灰岩岩石物理模型 响应特征进行进一步分析。 该论文有图 56 幅，表 8 个，参考文献 119 篇。 关键词关键词煤系灰岩；果蝇优化算法；自相容近似模型；正演模拟；地震响应 II Abstract Coal mine water disaster always existed side by side with coal production, causing severe effect on coal safety production. The aquifer of the coal seam floor mainly consists of Carboniferous and Ordovician limestone and etc., among which the water-abundance of Ordovician limestone is better. Based on the basic theory of rock physics, this thesis established the rock physics model of saturated limestone and variable porosity saturated rock to carry on elastic wave finite difference forward simulation. Thus we conducted an analysis on the seismic response characteristics of water-saturated and variable porosity saturated limestone. The finite differenceFD has been widely applied to the numerical seismic elastic wave simulations, among which FD coefficients determine the precision of numerical simulation. In this thesis, the FD coefficients were captured by fruit fly optimization algorithmFOA, which minimized the absolute error of the space-domain dispersion relation of acoustic equation. Compared with Taylor series expansion TEM, the results showed that FOA-based had better capability to suppress the numerical dispersion. Meanwhile, based on the recursive integral perfectly matched layer absorptionRIPML , this thesis extended the FOA to the first order velocity-stress equation for coalfield limestone numerical modeling. The single-axis and tri-axial stress loading tests on limestone were conducted through ultrasonic P˙S wave integrated tester for accurate P-wave and S-wave velocities measurement of rock sample at room temperature. The self-consistent approximation model was adopted to calculate the modulus of saturated and saturated variable porosity limestone. Then the initial model of coalfield limestone and the rock physics models of saturated and saturated variable porosity were built. By carrying out the seismic wave FD forward modeling and horizontal superposition, the seismic wave characteristics of the limestone initial saturated model and saturated models with porosity of 5, 8 and 10 were analyzed and made a comparison. The modeling results indicated that the reflected wave ed by the rhythm type of thin interbedding of coalfield limestone and sand shale was a composite wave, and the larger the impedance difference between the coalfield limestone and the sand shale surrounding rock, the greater the amplitude of the seismic amplitude response, on the contrary, the amplitude would be smaller. Due to III the complex geology structure of the ground stratum, it is necessary to have a further analysis on the response characteristics of the limestone rock physics model. The thesis includes 56 figures, 8 tables and 119 references. Keywords Coalfield limestone; Fruit fly optimization algorithm; Self-consistent approximation model; Forward modeling; Seismic wave response IV 目 录 目 录 摘要摘要................................................................................................................................ I 目录目录............................................................................................................................. IV 图清单图清单...................................................................................................................... VIII 表清单表清单........................................................................................................................ XII 变量注释表变量注释表 ............................................................................................................. VIII 1 绪论绪论............................................................................................................................ 1 1.1 研究目的和意义 ..................................................................................................... 1 1.2 国内外研究现状 ..................................................................................................... 2 1.3 研究内容 ................................................................................................................. 6 1.4 技术路线 ................................................................................................................. 7 2 岩石物理基础岩石物理基础 ........................................................................................................... 8 2.1 等效弹性模量边界 ................................................................................................. 8 2.2 几种经典的等效介质理论模型 ........................................................................... 13 2.3 流体渗透率 ........................................................................................................... 15 2.4 小结 ....................................................................................................................... 16 3 煤系灰岩岩样弹性测试煤系灰岩岩样弹性测试 ......................................................................................... 17 3.1 研究区区域地质概况 ........................................................................................... 17 3.2 岩样采集与样品制备 ........................................................................................... 17 3.3 实验设计 ............................................................................................................... 18 3.4 测试原理及仪器设备 ........................................................................................... 18 3.5 灰岩应力作用下纵横波测试与成果分析 ........................................................... 20 3.6 小结 ....................................................................................................................... 28 4 有限差分数值模拟方法有限差分数值模拟方法 ......................................................................................... 30 4.1 有限差分波动方程 ............................................................................................... 30 4.2 果蝇优化算法 ....................................................................................................... 31 4.3 果蝇优化算法测试与差分系数提取 ................................................................... 34 4.4 小结 ....................................................................................................................... 42 5 灰岩岩石物理建模与波场分析灰岩岩石物理建模与波场分析 ............................................................................. 43 5.1 初始模型建立 ....................................................................................................... 43 V 5.2 模型岩石物理参数 ............................................................................................... 45 5.3 灰岩组模量计算 ................................................................................................... 46 5.4 子波频率选取 ....................................................................................................... 46 5.5 灰岩组正演模拟与波场分析 ............................................................................... 47 5.6 小结 ....................................................................................................................... 67 6 结论与建议结论与建议 ............................................................................................................. 69 6.1 结论 ....................................................................................................................... 69 6.2 问题与建议 ........................................................................................................... 70 参考文献参考文献 ..................................................................................................................... 71 作者简历作者简历 ..................................................................................................................... 78 学位论文原创性声明学位论文原创性声明 ................................................................................................. 79 学位论文数据集学位论文数据集 ......................................................................................................... 80 VI Contents Abstract ........................................................................................................................ II Contents ..................................................................................................................... VI List of Figures ......................................................................................................... VIII List of Tables ............................................................................................................. XII List of Variables ...................................................................................................... VIII 1 Introduction ............................................................................................................... 1 1.1 Aims and Significance of the Research ................................................................... 1 1.2 Research Status at Home and Abroad ...................................................................... 2 1.3 Main Studies ............................................................................................................ 6 1.4 Technical Route ....................................................................................................... 7 2 Basic Theory of Rock Physics .................................................................................. 8 2.1 Bound of Effective Elastic modulus ........................................................................ 8 2.2 Theory of Several Classical Effective Media Models ........................................... 13 2.3 Fluid Permeability .................................................................................................. 15 2.4 Summary ................................................................................................................ 16 3 Elastic Parameter Test of Coalfield Limestone .................................................... 17 3.1 Regional Geology Survey of Study Area ............................................................... 17 3.2 Rock Sampling and Preparation ............................................................................. 17 3.3 Experiment Design ................................................................................................. 18 3.4 Test Principle and Equipment ................................................................................ 18 3.5 Test and Result Analysis of P-wave and S-wave under Stress .............................. 20 3.6 Summary ................................................................................................................ 28 4 Finite Difference Scheme for Numerical Modeling.............................................. 30 4.1 Finite Difference for Seismic Wave Equation ....................................................... 30 4.2 Fruit Fly Optimization Algorithm .......................................................................... 31 4.3 The Capture of FD Coefficients for FOA and s Test ................................ 34 4.4 Summary ................................................................................................................ 42 5 Limestone Rock Physics Modeling and Analysis on Seismic wave Characteristics ............................................................................................................ 43 VII 5.1 The Foundation of Initial Model ............................................................................ 43 5.2 Parameters of Rock Physics Model ....................................................................... 45 5.3 Calculation of Limestone Modulus ........................................................................ 46 5.4 Wavelet Frequency Selection ................................................................................ 46 5.5 Forward Modeling of Limestone and Analysis on Seismic Wave Characteristics 47 5.6 Summary ................................................................................................................ 67 6 Conclusions and Suggestions ................................................................................. 69 6.1 Conclusions ............................................................................................................ 69 6.2 Questions and Suggestions .................................................................................... 70 References ................................................................................................................... 71 Author’s Resume ........................................................................................................ 78 Declaration of Thesis ................................................................................................. 79 Thesis Data Collection ..............................................................