| 基于背景噪声成像方法的新疆呼图壁储气库地区近地表速度结构研究 |
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| 引用本文： | 王娟娟,姚华建,王伟涛,王宝善,李成,魏斌,冯磊.基于背景噪声成像方法的新疆呼图壁储气库地区近地表速度结构研究[J].地球物理学报,2018,61(11):4436-4447. |
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| 作者姓名： | 王娟娟 姚华建 王伟涛 王宝善 李成 魏斌 冯磊 |
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| 作者单位： | 1. 中国科学技术大学地球和空间科学学院, 合肥 230026;2. 蒙城地球物理国家野外科学观测研究站, 安徽蒙城;3. 中国地震局地球物理研究所, 北京 100081;4. 新疆维吾尔自治区地震局, 乌鲁木齐 830011 |
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| 基金项目： | 中国地震局公益性行业科研专项（201508008），中国自然科学基金面上项目（41474051），云南省陈颙院士工作站专项经费（2014IC007）联合资助. |
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| 摘 要： | 近年来，背景噪声成像方法在恢复高频面波信号及获取近地表速度结构方面得到了广泛的应用，本文将该方法应用于准噶尔盆地南缘的呼图壁背斜地区的呼图壁储气库.采用储气库及其周边区域22个台站记录的连续背景噪声数据的垂直分量，通过噪声互相关方法获得了台站对之间的瑞利面波经验格林函数，并进一步提取了0.5~1.5 s的基阶瑞利面波群速度频散曲线.首先根据区域平均频散曲线得到了该地区地下数百米的平均一维横波速度结构，然后利用基于面波射线路径追踪的面波频散直接成像方法得到该地区深度为500 m以上的三维横波速度结构.反演结果显示该地区沉积层较厚，整体横波速度值较小（0.4~0.9 km·s-1）.储气库在地表投影区域的横波速度值较小，这可能是由于抽注水、气引起的沉积岩石裂隙所导致.储气库东北和东南方向均有明显的相对高速区，推测是区域地下水位和地形起伏综合作用的结果.本研究获得的近地表三维速度结构为呼图壁储气库地区的上覆地层物性研究、区域微震精定位、场地效应的评估和去除浅层影响的深部介质成像等研究提供了重要基础.
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| 关 键 词： | 背景噪声 群速度 面波层析成像 近地表横波速度结构 储气库 |
| 收稿时间： | 2018-01-16 |
Study of the near-surface velocity structure of the Hutubi gas storage area in Xinjiang from ambient noise tomography |
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| WANG JuanJuan,YAO HuaJian,WANG WeiTao,WANG BaoShan,LI Cheng,WEI Bin,FENG Lei.Study of the near-surface velocity structure of the Hutubi gas storage area in Xinjiang from ambient noise tomography[J].Chinese Journal of Geophysics,2018,61(11):4436-4447. |
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| Authors: | WANG JuanJuan YAO HuaJian WANG WeiTao WANG BaoShan LI Cheng WEI Bin FENG Lei |
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| Institution: | 1. School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China;2. Mengcheng National Geophysical Observatory, University of Science and Technology of China, Mengcheng Anhui, China;3. Institute of Geophysics, China Earthquake Administration, Beijing 100081, China;4. Earthquake Administration of Xinjiang Uygur Autonomous Region, Urumqi 830011, China |
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| Abstract: | Recently, ambient noise tomography has been widely used in retrieving high frequency surface waves and getting near-surface velocity models. Here we applied this method to the Hutubi gas storage area, which is located at the Hutubi anticline in the southern margin of Junggar basin in Xinjiang. We calculated the cross-correlation functions of the vertical component of continuous ambient noise data of 22 stations in the Hutubi gas storage and its neighboring regions, and measured the fundamental-mode Rayleigh wave group velocity dispersion curves in the period band 0.5~1.5 s. Firstly, using the average dispersion curve in this area, we obtained the one-dimensional average shear-velocity model, and then we used a direct three-dimensional surface-wave tomographic method based on period-dependent raytracing to invert for the 3-D near-surface shear-velocity structure to the maximum depth about 500 meters underground. The results show that the sedimentary layers in this area are thick and have low shear-wave velocity (about 0.4~0.9 km·s-1) in general. The low velocity structure in the gas storage region is probably caused by the fractured sedimentary rocks due to gas and water extraction and injection. In the southeast and northeast of the gas storage, there are two zones with relatively high velocities, which are probably due to the integrated effects of the local groundwater level and topographic relief. The near-surface velocity model can provide an important basis for understanding the overlying formation characteristics, precise location of local microearthquakes, assessing near-surface site effect, and removing the shallow structural effect in imaging the deep structures. |
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| Keywords: | Ambient noise Group velocity Surface-wave tomography Near-surface shear-wave velocity structure Gas storage |
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