海洋三维VC观测系统优化设计

doi:10.13278/j.cnki.jjuese.20170011

摘要/Abstract

摘要： 观测系统设计在地震勘探中起着至关重要的作用，最佳观测系统不仅可以提高资料品质，还能够降低采集成本。通过对海洋垂直缆（vertical cable，VC）进行正演模拟我们发现，随着偏移距的增大，同相轴会出现交叉、合并现象，地层顺序也会发生变化。我们针对单VC和多VC的特点，分别设计了相应的观测系统。然后对所设计的观测系统进行评价与优化，并得出了一些有益的结论：采用增加激发点密度的方法对面元覆盖次数的改善效果要好于采用增加激发面积的方法对面元覆盖次数的改善效果；当目标层存在倾角时，通过在构造走向上增加激发线条数，同时在下倾方向上增加激发线长度可以补偿照明损失；当目标层为背斜或向斜时，通过增大最大环半径来增加背斜和向斜照明范围的方法奏效甚微；当激发面积和接收面积相等时，通过同时增大激发面积和接收面积来提高中心区域面元覆盖次数的方法行不通，而当激发面积大于接收面积时则该问题得以解决。

关键词: 垂直缆, 观测系统, 面元覆盖, 照明分析, 正演模拟, 天然气水合物, 海洋三维地震勘探

Abstract: Geometry design plays an important part in seismic exploration. Optimum geometry can not only improve the quality of datum but also reduce the cost of acquisition. Through the forward modeling, with the increase of offset we found the phenomenon that the events would cross or even merge, and the stratigraphic sequence would become confused. According to the characteristics of a single vertical cable and multiple vertical cables, we designed the corresponding geometries, and then evaluated and optimized the designed geometries. The conclusions are drawn as follows:First, to increase shot point density is better than to increase shot area to improve bin fold; when a shot line interval is equal to a shot point interval, the distribution uniformity of a bin fold in each bin is the best. Second, when the target layer is inclined, the illumination area shows the shape of trapezoid, and part of the area can't be illuminated. The illumination loss can be compensated through increasing the number of shot line along the structural trend, and increasing the length of shot line along the downdip direction at the same time. Third, when the target layer is anticline or syncline, to increase the scope of illumination by increasing the radius of the maximum ring is small, although the marine vertical cable is moved every where. The best way is to deploy multiple marine vertical cable in a ring. Fourth, when a shot area is equal to a receiver area, to improve bin fold of the center area by increasing both of them doesn't work. However, it works thoroughly when the shot area is bigger than the receiver area.

Key words: vertical cable, geometry, bin fold, illumination analysis, forward modeling, natural gas hydrate, three dimensional marine seismic exploration

中图分类号:

P631

安振芳, 张进, 张建中. 海洋三维VC观测系统优化设计[J]. 吉林大学学报(地球科学版), 2018, 48(1): 271-284.

An Zhenfang, Zhang Jin, Zhang Jianzhong. Geometry Optimization Design of Three Dimensional Marine Vertical Cable[J]. Journal of Jilin University(Earth Science Edition), 2018, 48(1): 271-284.

参考文献

[1] 王淑红, 宋海斌, 颜文. 全球与区域天然气水合物中天然气资源量估算[J]. 地球物理学进展, 2005, 20(4): 1145-1154. Wang Shuhong, Song Haibin, Yan Wen. The Global and Regional Estimation of Gas Resource Quantity in Gas Hydrates[J]. Progress in Geophysics, 2005, 20(4): 1145-1154.
[2] 谈顺佳, 于常青, 聂逢君, 等. 青海南部天然气水合物二维地震探测技术方法试验研究[J]. 地球物理学进展, 2015, 30(2): 817-828. Tan Shunjia, Yu Changqing, Nie Fengjun, et al. The Experimental Study of 2D Seismic Exploration Technology for Gas Hydrate in the Southern of Qinghai[J]. Progress in Geophysics, 2015, 30(2): 817-828.
[3] 孙嘉鑫, 宁伏龙, 郑明明, 等. 室内沉积物中天然气水合物形成数值模拟研究[J]. 天然气地球科学, 2015, 26(11): 2172-2184. Sun Jiaxin, Ning Fulong, Zheng Mingming, et al. Numerical Simulation on Natural Gas Hydrate Formation Within Porous Media Using Constant Volume Method[J]. Natural Gas Geoscience, 2015, 26(11): 2172-2184.
[4] 唐志远, 胡云亭, 郭清正, 等. 天然气水合物勘探开发新技术进展[J]. 地球物理学进展, 2015, 30(2): 805-816. Tang Zhiyuan, Hu Yunting, Guo Qingzheng, et al. Advances in Natural Gas Hydrate Exploration and Development Technology[J]. Progress in Geophysics, 2015, 30(2): 805-816.
[5] 李鹏. 海上全方位观测系统的采集设计方法技术研究[D]. 武汉: 中国地质大学(武汉), 2014. Li Peng. Study on the Geometries Design of Marine Full-Zimuth Acquisition[D]. Wuhan: China University of Geosciences, 2014.
[6] 吕晓春. 面向目标照明与成像的海上多方位及宽方位观测系统的评价与优化[D]. 武汉: 中国地质大学(武汉), 2014. Lü Xiaochun. Evaluation and Optimization of Marine Wide-Azimuth and Multi-Azimuth Geometry Acquisition for Target-Oriented Illumination and Imaging[D]. Wuhan: China University of Geosciences, 2014.
[7] Krail P M. Vertical Cable as a Subsalt Imaging Tool[J]. The Leading Edge, 1994, 13(8): 885-887.
[8] Krail P M. Measurements of Cable Shape in a Cross Current[J]. Geophysics, 1994, 59(7): 1156.
[9] Rodriguez-Suarez C, Stewart R R. Survey Design for Vertical Cable Seismic Acquisition[C]//61st EAGE Conference and Exhibition International. Houten: EAGE, 1999.
[10] Moldoveanu N, Henman R, Vlasin J, et al. Bottom Referenced Vertical Hydrophone Arrays-Towed Streamers-a Comparison Study[C]//59th EAGE Conference & Exhibition. Houten: EAGE, 1997: B019.
[11] Ikelle L T. Attenuating Primaries and Free-Surface Multiples of Vertical Cable(VC) Data While Preserving Receiver Ghosts of Primaries[J]. Geophysics, 2001, 66(3): 953-963.
[12] Ikelle L T, Amundsen L, Yoo S. An Optimization of the Inverse Scattering Multiple Attenuation Method for OBS and VC Data[J]. Geophysics, 2002, 67(4): 1293-1303.
[13] Wilson R J. Potential Impacts of Vertical Cable Seismic: Modeling, Resolution and Multiple Attenuation[D]. Texas: Texas A & M University, 2002.
[14] Sun C W, Stratton J, Anderson J, et al. Separation of Up-Going and Down-Going Wave Fields of Vertical Cable Data[J]. Chinese Journal of Oceanology and Limnology, 2005, 23(3): 259-268.
[15] Leach P E. Strathspey Vertical-Cable Seismic Survey: A North-Sea First[C]//Petroleum Geology of Northwest Europe: Proceedings of the 5th Conference. London: Geological Society, 1999: 1235-1242.
[16] Zhang J Z, Huang Y Q, Song L P, et al. Fast and Accurate 3-D Ray Tracing Using Bilinear Traveltime Interpolation and the Wave Front Group Marching[J]. Geophysical Journal International, 2011, 184(3): 1327-1340.
[17] Muerdter D, Ratcliff D. Understanding Subsalt Illumination Through Ray-Trace Modeling, Part 1: Simple 2-D Salt Models[J]. The Leading Edge, 2001, 20(6): 578-594.
[18] Muerdter D, Kelly M, Ratcliff D. Understanding Subsalt Illumination Through Ray-Trace Modeling, Part 2: Dipping Salt Bodies, Salt Peaks, and Nonreciprocity of Subsalt Amplitude Response[J]. The Leading Edge, 2001, 20(7): 688-697.
[19] Muerdter D, Ratcliff D. Understanding Subsalt Illumination Through Ray-Trace Modeling, Part 3: Salt Ridges and Furrows, and the Impact of Acquisition Orientation[J]. The Leading Edge, 2001, 20(8): 803-816.
[20] 杨木壮, 王明君, 吕万军. 南海西北陆坡天然气水合物成矿条件研究[M]. 北京: 气象出版社, 2008. Yang Muzhuang, Wang Mingjun, Lü Wanjun.The Research of Metallogenic Conditions of Natural Gas Hydrate in the Northwest Slope of the South China Sea[M]. Beijing: Meteorological Press, 2008.
[21] 肖钢, 白玉湖, 董锦. 天然气水合物综论[M]. 北京: 高等教育出版社, 2012. Xiao Gang, Bai Yuhu, Dong Jin.Review of Natural Gas Hydrate[M]. Beijing: Higher Education Press, 2012.
[22] Kvenvolden K A. Gas Hydrate-Geological Perspective and Global Change[J]. Reviews of Geophysics, 1993, 31(2): 173-187.
[23] Max M D, Lowrie A. Oceanic Methane Hydrates: A "Frontier" Gas Resource[J]. Journal of Petroleum Geology, 1996, 19(1): 41-56.
[24] 邓飞, 刘超颖. 三维射线快速追踪及高斯射线束正演[J]. 石油地球物理勘探, 2009, 44(2): 158-165. Deng Fei, Liu Chaoying. 3-D Rapid Ray-Tracing and Gaussian Ray-Beam Forward Simulation[J]. Oil Geophysical Prospecting, 2009, 44(2): 158-165.
[25] 宋维琪, 杨晓东. 基于射线追踪的微地震多波场正演模拟[J]. 地球物理学进展, 2012, 27(4): 1501-1508. Song Weiqi, Yang Xiaodong. The Multi-Wave Field Forward Simulation of Micro-Seismic Based on Ray Tracing[J]. Progress in Geophysics, 2012, 27(4): 1501-1508.
[26] 郭宏伟, 王尚旭, 孙文博. 基于非均质体的波动方程有限元正演模拟[J]. 石油物探, 2012, 51(4): 319-326. Guo Hongwei, Wang Shangxu, Sun Wenbo.Wave Equation Modeling by Finite-Element Method for Heterogeneous Body[J]. Geophysical Prospecting for Petroleum, 2012, 51(4): 319-326.
[27] 李庆洋, 李振春, 黄建平, 等. 基于贴体全交错网格的起伏地表正演模拟影响因素[J]. 吉林大学学报(地球科学版), 2016, 46(3): 920-929. Li Qingyang, Li Zhenchun, Huang Jianping, et al.Factor Analysis of Seismic Modeling with Topography Based on a Fully Staggered Body-Fitted Grids[J]. Journal of Jilin University(Earth Science Edition), 2016, 46(3): 920-929.

Metrics

Viewed

Full text

Abstract

Cited

Shared

Discussed