Quality control method for secondary location of OBN data
WANG Zhongcheng1, TONG Siyou1,2, ZHOU Huawei1,3, FANG Yunfeng4, SUN Yunsong4, XU Xiugang1
1. Key Lab of Submarine Geosciences and Prospecting Techniques, MOE, Ocean University of China, Qingdao, Shandong 266100, China; 2. Laboratory for Marine Mineral Resources, Pilot National Laboratry for Marine Science and Tech-nologyc(Qingdao), Qingdao, Shandong 266061, China; 3. Department of Earth and Atmospheric Sciences, University of Houston, Houston 77204, America; 4. BGP R&D Center, CNPC, Zhouzhou, Hebei 072751, China
Abstract：During ocean bottom node (OBN) survey, geo-phones need to be placed on the seafloor. Howe-ver, due to the complex marine environment, the actual implantation position of OBN on the seafloor usually deviates from the design position and needs to be relocated. At present, a variety of secondary location methods have been developed, but their proposers focus on the principle and application effect of a secondary location method; there is little systematic description of effective quality control in field application. With this regard, based on the equivalent velocity method of secondary positioning, this paper studies the factors that affect the secondary positioning accuracy of OBN receiver points, including the accuracy of picked direct wave travel time, geometry, and time shift. The results show that the accuracy of picked direct wave travel time has a crucial impact on the secondary positioning accuracy;if the shot points and the receiver point are projected to the x-axis, y-axis, and z-axis respectively, the distribution of the shot points will be more uniform and more symmetrical relative to the receiver point, and the positioning accuracy will be higher in this direction;the systematic error of travel time is difficult to identify, but it has a great impact on the positioning accuracy in the z direction. Finally, this paper provides methods and suggestions for quality control of secondary positioning of OBN data. Firstly, the first-break travel time is sifted to ensure the accuracy of picked first-break travel time. Then the time shift is introduced as an additional variable to calculate the possible shift of first-break travel time, and the first-break travel time of shot points in a symmetrical distribution relative to the receiver point is selected for calculation. Finally, the processor can monitor the secondary positioning quality artificially according to the comparison between the shapes of the direct wave after NMO, the spatial distribution of travel time errors, mathematical statistics, and other aspects of the common detector gathers before and after secondary positioning.
韩立强,常稳. 海底电缆初至波二次定位技术的应用[J].石油物探,2003,42(4):501-504.HAN Liqiang,CHANG Wen. Application of first break second positioning technique in OBC[J].Geophysical Prospecting for Petroleum,2003,42(4):501-504.
[2]
李丽青,陈玺,伍宗良,等. 深水环境下OBS的二次定位技术[J].海洋地质前沿,2013,29(11):54-61.LI Liqing,CHEN Xi,WU Zongliang,et al. Technique for relocating OBS in deep water environment[J].Marine Geology Frontiers,2013,29(11):54-61.
[3]
敖威,赵明辉,丘学林,等. 西南印度洋中脊三维地震探测中炮点与海底地震仪的位置校正[J].地球物理学报,2010,53(12):2982-2991.AO Wei,ZHAO Minghui,QIU Xuelin,et al. The correction of shot and OBS position in the 3D seismic experiment of the SW Indian Ocean ridge[J].Chinese Journal of Geophysics,2010,53(12):2982-2991.
[4]
张莉,赵明辉,王建,等. 南海中央次海盆OBS位置校正及三维地震探测新进展[J].地球科学——中国地质大学学报,2013,38(1):33-42.ZHANG Li,ZHAO Minghui,WANG Jian,et al. Correction of OBS position and recent advanced of 3D seismic exploration in the Central Sub-Basin of South China Sea[J].Earth Science:Journal of China University of Geosciences,2013,38(1):33-42.
[5]
刘斌. 海底地震仪重新定位:以东沙群岛海域为例[J].热带海洋学报,2015,34(2):66-70.LIU Bin. Ocean bottom seismometer relocation:Using Dongsha sea area as an example[J].Journal of Tropical Oceanography,2015,34(2):66-70.
[6]
葛晓丹. 浅海地震勘探海底电缆初至波二次定位方法研究[D].山东青岛:中国海洋大学,2015.GE Xiaodan. A Study on the Second Positioning Technique for the First Break in OBC Seismic Exploration of Shallow Sea[D].Ocean University of China,Qingdao,Shandong,2015.
[7]
刘慧敏,王振杰,吴绍玉,等. 顾及声线弯曲的浅海多目标水声定位算法[J].石油地球物理勘探,2019,54(1):9-15.LIU Huimin,WANG Zhenjie,WU Shaoyu,et al. A positioning determination of multi-transponders with sound ray bending in shallow waters[J].Oil Geophy-sical Prospecting,2019,54(1):9-15.
[8]
刘慧敏,王振杰,赵爽. 深度约束的浅海多目标声学定位方法[J].石油地球物理勘探,2019,54(6):1181-1187.LIU Huimin,WANG Zhenjie,ZHAO Shuang. A depth-constraint multi-target positioning acoustic approach in shallow waters[J].Oil Geophysical Prospecting,2019,54(6):1181-1187.
[9]
徐维秀. 浅水域检波点自动重定位技术[J].石油地球物理勘探,2011,46(1):6-11.XU Weixiu. Automatic repositioning technique for shallow water receiver points[J].Oil Geophysical Prospecting,2011,46(1):6-11.
[10]
杨正华,张慧静. 海底电缆地震勘探中近正四面体法二次定位技术[J].石油地球物理勘探,2013,48(2):163-170.YANG Zhenghua,ZHANG Huijing. An approximate tetrahedron method for the secondary positioning in OBC seismic survey[J].Oil Geophysical Prospecting,2013,48(2):163-170.
[11]
倪成洲,全海燕,陈刚,等. 一种高精度初至波二次定位新方法——搜索法[J].石油地球物理勘探,2008,43(2):131-133.NI Chengzhou,QUAN Haiyan,CHEN Gang,et al. A new method for high-precision first break secondary positioning:Search method[J].Oil Geophysical Prospecting,2008,43(2):131-133.
[12]
肖永新,杨海申,蒋先艺,等. OBC勘探中扫描拟合二次定位方法[J].石油地球物理勘探,2012,47(3):366-370.XIAO Yongxin,YANG Haishen,JIANG Xianyi,et al. A secondary positioning method by grid scanning and curved-surface fitting in OBC survey[J].Oil Geophysical Prospecting,2012,47(3):366-370.
[13]
马德堂,赵会兵,伍忠良. 基于直达波旅行时的OBS混合定位方法[J].石油地球物理勘探,2013,48(5):677-681.MA Detang,ZHAO Huibing,WU Zhongliang. An OBS positioning mixed method based on travel-time of direct wave[J].Oil Geophysical Prospecting,2013,48(5):677-681.
[14]
杨海申,徐丽军,马杰,等. 矢量叠加初至波定位方法及精度评价[J].石油地球物理勘探,2021,56(1):49-56.YANG Haishen,XU Lijun,MA Jie,et al. First-break positioning and accuracy evaluation based on vector superposition[J].Oil Geophysical Prospecting,2021,56(1):49-56.
[15]
王忠成,周华伟,童思友,等. 深水海底节点二次定位方法[J].石油地球物理勘探,2020,55(2):242-247.WANG Zhongcheng,ZHOU Huawei,Tong Siyou,et al. Secondary positioning of deep ocean bottom nodes[J].Oil Geophysical Prospecting,2020,55(2):242-247.
[16]
韩复兴,孙建国,王坤. 深海声道对波场传播的影响[J].石油地球物理勘探,2014,49(3):444-450.HAN Fuxing,SUN Jianguo,WANG Kun. Deep sea channel influence on wave field energy propagation[J].Oil Geophysical Prospecting,2014,49(3):444-450.
[17]
徐维秀,段卫星,刘治红,等. 提高初至波二次定位精度技术的探讨[J].石油物探,2009,48(3):239-243.XU Weixiu,DUAN Weixing,LIU Zhihong,et al. Discussion on the technology for improving the accuracy of secondary positioning with first break[J].Geophysical Prospecting for Petroleum,2009,48(3):239-243.
[18]
易昌华,任文静,王钗. 二次水声定位系统误差分析[J].石油地球物理勘探,2009,44(2):136-139.YI Changhua,REN Wenjing, WANG Chai. Analysis on error of secondary acoustic positioning system[J].Oil Geophysical Prospecting,2009,44(2):136-139.
