Physical modeling of seismic response for the coal seams of Yan'an Formation in loess tableland of North China
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摘要: 针对黄土塬区延安组煤层地震响应复杂问题进行地震物理模拟研究。首先,研发适用于黄土塬地表干黄土层和煤层的模型材料,经过多次试验,最终选用在硅橡胶中添加硅气凝胶粉末的混合材料模拟疏松黄土塬地表层,选用在硅橡胶中添加超细碳粉的混合材料模拟低速低密度煤层;通过模具控制层位、逐层浇筑、三维雕刻起伏地层等方法,制作黄土塬区典型地质结构的三维地震物理模型,并开展地震物理模拟及地震成像分析。结果表明,延安组煤层与围岩较大的波阻抗差异形成较强的反射振幅,对下部地层的成像有较强的屏蔽作用;较厚的多组煤层之间会形成层间多次波,影响下伏地层的成像。用地震振幅属性对煤层进行刻画时,计算时窗大于40 ms更有利于煤层识别,但由于煤层存在调谐效应,用地震属性预测煤层厚度存在一定陷阱。Abstract: A seismic physical simulation is carried out for the complex seismic response of the coal seam of Yan'an Formation in the loess tableland. First, the physical model materials for the dry layer near the surface of the loess tableland and the coal seam are developed. After several tests, a mixture of silicone rubber with silicon aerogel powder is selected to simulate the surface of the loess tableland, and the mixture with ultra-fine carbon powder added to silicone rubber is used to simulate the low-speed and low-density coal seam. Through the methods of molds control layer, layer by layer pouring, three-dimensional carving of undulating strata, a three-dimensional seismic physical model of the typical geological structure in the loess tableland is constructed, and seismic physical simulation and seismic imaging analysis are carried out. The results show that there is a strong reflection amplitude because of the great difference in impedance between the coal seam and surrounding rock of Yan'an Formation. Therefore, it has a strong shielding effect on the imaging of the lower strata. There are internal multiple waves in the multiple sets of coal seams, affecting the imaging of the underlying layer. The calculation time window greater than 40 ms is more favorable to coal seam identification when the coal seam is described by the seismic amplitude attribute. But there are some traps in predicting coal seam thickness by seismic attributes because of the coal seams tuning effect.
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表 1 三维地质模型设计参数与测量参数
Table 1 Design parameters and test parameters of the model
地层名称 模型设计vP/(m·s–1) 模型实测vP/(m·s–1) 模型密度/(g·cm–3) 实际地层vP/(m·s–1) 近地表 900 939 1.022 1 800 KT_Q 1 200 1 212 1.056 2 400 KT_K1hd 2 100 2 104 1.122 4 200 KT_K1hh 2 150 2 117 1.130 4 300 KT_K1hc 2 000 2 000 1.100 4 000 KT_K1yj 2 200 2 202 1.142 4 400 KT_J2a 2 125 2 148 1.133 4 250 KT_y2z 2 150 2 178 1.134 4 300 KT_y8 2 125 2 145 1.135 4 250 KT_y9 2 250 2 296 1.137 4 500 KT_y10 2 300 2 308 1.182 4 600 KT_c6 1 600 1 621 1.061 3 200 KT_c7 2 200 2 208 1.100 4 400 KT_c81 2 275 2 303 1.129 4 550 KT_c91 2 600 2 663 1.284 5 200 表 2 物理模型实验的观测系统参数
Table 2 Observation system parameters of the physical model experiment
参数 物理模型采集 野外采集 震源主频 170 kHz 17 Hz 炮线距 28 mm 560 m 测线距 16 mm 320 m 束线距 16 mm 320 m 采样点数 4 500 4 500 炮点距 4 mm 80 m 道间距 2 mm 40 m 采样间隔 0.08 μs 0.8 ms 覆盖次数 110 110 面元 2 mm×1 mm 40 m×20 m -
[1] 刘占勇, 江涛, 宋洪柱, 等. 中国煤炭资源勘查开发程度分析[J]. 煤田地质与勘探, 2013, 41(5): 1–5.. doi: 10.3969/j.issn.1001-1986.2013.05.001LIU Zhanyong, JIANG Tao, SONG Hongzhu, et al. Analysis of explorative and exploitative degree of China coal resources[J]. Coal Geology & Exploration, 2013, 41(5): 1–5.. doi: 10.3969/j.issn.1001-1986.2013.05.001 [2] 程建远, 聂爱兰, 张鹏. 煤炭物探技术的主要进展及发展趋势[J]. 煤田地质与勘探, 2016, 44(6): 136–141.. doi: 10.3969/j.issn.1001-1986.2016.06.025CHENG Jianyuan, NIE Ailan, ZHANG Peng. Outstanding progress and development trend of coal geophysics[J]. Coal Geology & Exploration, 2016, 44(6): 136–141.. doi: 10.3969/j.issn.1001-1986.2016.06.025 [3] 滕吉文, 司芗, 王玉辰. 我国化石能源勘探、开发潜能与未来[J]. 石油物探, 2021, 60(1): 1–12.. doi: 10.3969/j.issn.1000-1441.2021.01.001TENG Jiwen, SI Xiang, WANG Yuchen. Potential and future of fossil fuel exploration and development in China[J]. Geophysical Prospecting for Petroleum, 2021, 60(1): 1–12.. doi: 10.3969/j.issn.1000-1441.2021.01.001 [4] 程建远, 王寿全, 宋国龙. 地震勘探技术的新进展与前景展望[J]. 煤田地质与勘探, 2009, 37(2): 55–58.. doi: 10.3969/j.issn.1001-1986.2009.02.015CHENG Jianyuan, WANG Shouquan, SONG Guolong. The new development and foreground expectation of seismic exploration[J]. Coal Geology & Exploration, 2009, 37(2): 55–58.. doi: 10.3969/j.issn.1001-1986.2009.02.015 [5] 滕吉文, 乔勇虎, 宋鹏汉. 我国煤炭需求、探查潜力与高效利用分析[J]. 地球物理学报, 2016, 59(12): 4633–4653.. doi: 10.6038/cjg20161224TENG Jiwen, QIAO Yonghu, SONG Penghan. Analysis of exploration, potential reserves and high efficient utilization of coal in China[J]. Chinese Journal of Geophysics(in Chinese), 2016, 59(12): 4633–4653.. doi: 10.6038/cjg20161224 [6] 程建远, 李宁, 侯世宁, 等. 黄土塬区地震勘探技术发展现状综述[J]. 中国煤炭地质, 2009, 21(12): 72–76.. doi: 10.3969/j.issn.1674-1803.2009.12.020CHENG Jianyuan, LI Ning, HOU Shining, et al. Development status overview of seismic prospecting technology in loess tableland[J]. Coal Geology of China, 2009, 21(12): 72–76.. doi: 10.3969/j.issn.1674-1803.2009.12.020 [7] 陈超群, 高秦, 何争光, 等. 鄂尔多斯盆地西南部巨厚黄土塬区非纵地震资料处理技术[J]. 煤田地质与勘探, 2017, 45(1): 143–151.. doi: 10.3969/j.issn.1001-1986.2017.01.028CEHN Chaoqun, GAO Qin, HE Zhengguang, et al. The off-line seismic exploration and its application in huge-thick loess area in Ordos Basin[J]. Coal Geology & Exploration, 2017, 45(1): 143–151.. doi: 10.3969/j.issn.1001-1986.2017.01.028 [8] 白万山, 刘田田, 李红桃. 黄土塬地区煤田地震勘探资料处理技术[J]. 煤田地质与勘探, 2014, 42(4): 82–85.. doi: 10.3969/j.issn.1001-1986.2014.04.018BAI Wanshan, LIU Tiantian, LI Hongtao. Processing technologies of seismic data from the coalfield in loess plateau area[J]. Coal Geology & Exploration, 2014, 42(4): 82–85.. doi: 10.3969/j.issn.1001-1986.2014.04.018 [9] 周俊杰, 王雨, 侯玮. 黄土塬地区煤田三维地震综合处理技术[J]. 地球物理学进展, 2016, 31(5): 2299–2305. https://d.wanfangdata.com.cn/periodical/dqwlxjz201605057ZHOU Junjie, WANG Yu, HOU Wei. 3D seismic comprehensive processing technology of coalfield in loess tableland[J]. Progress in Geophysics(in Chinese), 2016, 31(5): 2299–2305. https://d.wanfangdata.com.cn/periodical/dqwlxjz201605057 [10] 陈超群, 田媛媛, 高秦, 等. 基于随机函数数据重构的分频异常振幅衰减技术在巨厚黄土塬区的应用[J]. 石油物探, 2019, 58(5): 741–749.. doi: 10.3969/j.issn.1000-1441.2019.05.013CHEN Chaoqun, TIAN Yuanyuan, GAO Qin, et al. Frequency-division abnormal amplitude attenuation after data reconstruction based on random function and its application in the very thick loess tableland area, Ordos Basin[J]. Geophysical Prospecting for Petroleum, 2019, 58(5): 741–749.. doi: 10.3969/j.issn.1000-1441.2019.05.013 [11] 熊晓军, 贺振华, 黄德济. 三维波动方程正演及模型应用研究[J]. 石油物探, 2005, 44(6): 554–556.. doi: 10.3969/j.issn.1000-1441.2005.06.004XIONG Xiaojun, HE Zhenhua, HUANG Deji. The application of 3D wave equation forward and modeling[J]. Geophysical Prospecting for Petroleum, 2005, 44(6): 554–556.. doi: 10.3969/j.issn.1000-1441.2005.06.004 [12] 魏建新, 牟永光, 狄帮让. 三维地震物理模型的研究[J]. 石油地球物理勘探, 2002, 37(6): 556–561.. doi: 10.3321/j.issn:1000-7210.2002.06.002WEI Jianxin, MOU Yongguang, DI Bangrang. Study of 3D seismic physical model[J]. Oil Geophysical Prospecting, 2002, 37(6): 556–561.. doi: 10.3321/j.issn:1000-7210.2002.06.002 [13] 戴世鑫. 基于物理模型的煤田地震属性响应特征的关键技术研究[D]. 北京: 中国矿业大学(北京), 2012. http://cdmd.cnki.com.cn/article/cdmd-11413-1013132163.htmDAI Shixin. Research on key technology of response characteristics of seismic attributes based on the physical model[D]. Beijing: China University of Mining and Technology, 2012. http://cdmd.cnki.com.cn/article/cdmd-11413-1013132163.htm [14] 韩堂惠, 戴世鑫, 李小华, 等. 淮南煤系地层地震物理模型研究[J]. 煤炭学报, 2011, 36(4): 588–592. http://www.cnki.com.cn/Article/CJFDTotal-MTXB201104013.htmHAN Tanghui, DAI Shixin, LI Xiaohua, et al. Seismic physical modeling research on coal measure strata in Huainan[J]. Journal of China Coal Society, 2011, 36(4): 588–592. http://www.cnki.com.cn/Article/CJFDTotal-MTXB201104013.htm [15] 胡朝元. 薄煤层三维地震勘探技术: 以淮南张集矿区11-2煤为例[D]. 北京: 中国矿业大学(北京), 2011.HAN Chaoyuan. Three-Dimensional seismic exploration technology for thin coal seam: Taking the 11-2 coal seam in Zhangji coalming for example[D]. Beijing: China University of Mining & Technology(Beijing), 2011. [16] 陈晓智, 汤达祯, 许浩, 等. 彬长矿区延安组煤层发育特征及其控制因素分析[J]. 中国矿业, 2011, 20(2): 110–113.CHEN Xiaozhi, TANG Dazhen, XU Hao, et al. Development characteristics of coal seam and their controlling factors in Yan'an Formation in Binchang area[J]. China Mining Magazine, 2011, 20(2): 110–113. [17] 王雪秋. 复杂近地表地震波响应特征研究: 以中国西部地区为例[D]. 长春: 吉林大学, 2009.WANG Xueqiu. Study on seismic wave field under complex surface conditions of special physiognomy in West China[D]. Changchun: Jilin University, 2009. [18] 李智宏, 朱海龙, 赵群, 等. 地震物理模型材料研制与应用研究[J]. 地球物理学进展, 2009, 24(2): 408–417.. doi: 10.3969/j.issn.1004-2903.2009.02.006LI Zhihong, ZHU Hailong, ZHAO Qun, et al. Study and materialization of new seismic physical model building materials[J]. Progress in Geophysics, 2009, 24(2): 408–417.. doi: 10.3969/j.issn.1004-2903.2009.02.006 [19] 魏建新, 狄帮让. 地震物理模型中三维地质模型材料特性研究[J]. 石油物探, 2006, 45(6): 586–590.. doi: 10.3969/j.issn.1000-1441.2006.06.006WEI Jianxin, DI Bangrang. Properties of materials forming the 3D geological model in seismic physical model[J]. Geophysical Prospecting for Petroleum, 2006, 45(6): 586–590.. doi: 10.3969/j.issn.1000-1441.2006.06.006 [20] 赵群, 马国庆, 宗遐龄. 超声地震物理模型连续数据采集系统[J]. 地球物理学进展, 2004, 19(4): 786–788.. doi: 10.3969/j.issn.1004-2903.2004.04.014ZHAO Qun, MA Guoqing, ZONG Xialing. Continuance data acquisition system of ultrasonic seismic physical modeling[J]. Progress in Geophysics, 2004, 19(4): 786–788.. doi: 10.3969/j.issn.1004-2903.2004.04.014 [21] 狄帮让, 魏建新, 夏永革. 三维地震物理模型技术的效果与精度研究[J]. 石油地球物理勘探, 2002, 37(6): 562–568.. doi: 10.3321/j.issn:1000-7210.2002.06.003DI Bangrang, WEI Jianxin, XIA Yongge. Study on effects and precision of 3D seismic physical model technique[J]. Oil Geophysical Prospecting, 2002, 37(6): 562–568.. doi: 10.3321/j.issn:1000-7210.2002.06.003 [22] 赵鸿儒, 王铁男, 唐文榜. 中国地球物理模型试验的发展[J]. 地球物理学报, 1994, 37(增刊1): 269–276. https://www.cnki.com.cn/Article/CJFDTOTAL-DQWX4S1.023.htmZHAO Hongru, WANG Tienan, TANG Wenbang. The developments of geophysical modeling[J]. Acta Geophysica Sinica, 1994, 37(Sup. 1): 269–276. https://www.cnki.com.cn/Article/CJFDTOTAL-DQWX4S1.023.htm [23] 王开燕, 徐清彦, 张桂芳, 等. 地震属性分析技术综述[J]. 地球物理学进展, 2013, 28(2): 815–823. http://www.cnki.com.cn/Article/CJFDTotal-DQWJ201302033.htmWANG Kaiyan, XU Qingyan, ZHANG Guifang, et al. Summary of seismic attribute analysis[J]. Progress in Geophysics, 2013, 28(2): 815–823. http://www.cnki.com.cn/Article/CJFDTotal-DQWJ201302033.htm