Application of horizon-constrained grid tomography-based velocity modeling method in Block AG, Niger
MENG Huijie1, XU Xingrong1, WANG Yanxiang1, PENG Feifei2, WANG Jianhua1, LI Dongsheng1
1. Northwest Branch, Research Institute of Petroleum Exploration & Development, PetroChina, Lanzhou, Gansu 730020, China; 2. Exploration & Development Research Institute, Dagang Oilfield Company, PetroChina, Tianjin 300280, China
Abstract：Accurate imaging has always been a difficult problem in geophysical exploration. Although prestack depth migration technology can accurately return underground geological structures to their actual depth and spatial location, it depends on the precision of velocity modeling. To obtain a precise velocity model, this paper employs the velocity modeling software GeoEast-Diva and applies the horizon-constrained grid tomography-based velocity modeling method. Grids of different scales are used for stepwise tomographic inversion and continuous iterations on the basis of structural model constraints. A relatively accurate velocity model is ultimately obtained to improve imaging quality. Then, this method is employed to build a velocity model for Block AG in the Niger region. The results show that the method can be used to build a high-precision depth-domain velocity model, and the imaging results accurately reflect the properties of the underground media. Moreover, the imaging quality of the deep diapiric structures is improved, and pseudo structures caused by lateral velocity variations are eliminated.
基金资助:本项研究受中国石油尼日尔公司项目“3D seismic data reprocessing services in block Agadem，Niger”(CNPCNP/10/2021-0091)和中国石油勘探与生产分公司科技项目“双复杂地区速度场研究与叠前偏移成像技术攻关试验”(2022KT1502)联合资助。
马彦彦,李国发,张星宇,等.叠前深度偏移速度建模方法分析[J].石油地球物理勘探,2014,49(4): 687-693.MA Yanyan,LI Guofa,ZHANG Xingyu,et al.Strategy of velocity model building in prestack depth migration[J].Oil Geophysical Prospecting,2014,49(4):687-693.
[2]
LI G F,CAO M Q,ZHOU H.Effects of near-surface absorption on reflection characteristics of continental interbedded strata:the Dagang Oilfield as an example[J].Acta Geologica Sinica,2010,84(5):1306-1314.
[3]
刘文卿,王西文,刘洪,等.盐下构造速度建模与逆时偏移成像研究及应用[J].地球物理学报,2013,56(2):616-625.LIU Wenqing,WANG Xiwen,LIU Hong,et al.Application of velocity modeling and reverse time migration to subsalt structure[J].Chinese Journal of Geophysics,2013,56(2):616-625.
[4]
杨哲,王小卫,胡自多,等.基于束偏移的地层倾角约束网格层析建模[J].石油地球物理勘探,2018,53(增刊1):75-82.YANG Zhe,WANG Xiaowei,HU Ziduo,et al.Formation-dip-constrained grid tomography velocity mode-ling based on Gaussian beam migration[J].Oil Geophysical Prospecting,2018,53(S1):75-82.
[5]
谷延斌,张旭东,姚征,等.网格层析和高斯束偏移在深度域速度建模中的应用[J].石油地球物理勘探,2018,53(增刊1):112-116.GU Yanbin,ZHANG Xudong,YAO Zheng,et al.Application of the grid tomography and Gauss beam migration in velocity modelling in the depth domain[J].Oil Geophysical Prospecting,2018,53(S1):112-116.
[6]
潘兴祥,秦宁,曲志鹏,等.叠前深度偏移层析速度建模及应用[J].地球物理学进展,2013,28(6):3080-3085.PAN Xingxiang,QIN Ning,QU Zhipeng,et al.Tomography velocity modeling and application of prestack depth migration[J].Progress in Geophysics,2013,28(6):3080-3085.
[7]
HEWITT DIX C.Seismic velocities from surface measurements[J].Geophysics,1955,20(1):68-86.
[8]
CLAPP R,SAVA P,CLEARBOUT J F.Interval velocities estimation with a null space[R].Stanford Exploration Project Report,1998,147-156.
[9]
胡英,张研,陈立康,等.速度建模的影响因素与技术对策[J].石油物探,2006,45(5):503-507.HU Ying,ZHANG Yan,CHEN Likang,et al.Influencing factors and technical strategies for velocity modeling[J].Geophysical Prospecting for Petroleum,2006,45(5):503-507.
[10]
LAFOND C F,LEVANDER A R.Migration moveout analysis and depth focusing[J].Geophysics,1993,58(1):91-100.
[11]
李慧,成德安,金婧.网格层析成像速度建模方法与应用[J].石油地球物理勘探,2013,48(增刊1):12-16.LI Hui,CHENG Dean,JIN Jing.Velocity model building based on grid tomography[J].Oil Geophysical Prospecting,2013,48(S1):12-16.
[12]
辛可锋,王华忠,马在田.基于共聚焦点技术的成像速度建模方法研究[J].石油地球物理勘探,2004,39(5):519-525.XIN Kefeng,WANG Huazhong,MA Zaitian.Imaging velocity model-building method based on common focus point technique[J].Oil Geophysical Prospecting,2004,39(5):519-525.
[13]
王非翊,张凯,李振春,等.VTI介质各向异性参数角道集层析反演[J].石油地球物理勘探,2019,54(5):1057-1066.WANG Feiyi,ZHANG Kai,LI Zhenchun,et al.VTI medium anisotropic parameter tomography inversion based on angle domain common imaging gathers[J].Oil Geophysical Prospecting,2019,54(5):1057-1066.
[14]
张子良,李振春,张凯,等.地质模型约束的全波形速度建模反演及在复杂断块区的应用[J].石油地球物理勘探,2020,55(3):599-606.ZHANG Ziliang,LI Zhenchun,ZHANG Kai,et al.Research of geological model-constrained FWI and application in complex fault-block zones[J].Oil Geophysical Prospecting,2020,55(3):599-606.
[15]
王小卫,姚姚,刘文卿,等.波动方程叠前偏移在碳酸盐岩成像中的应用研究[J].天然气地球科学,2011,22(5):874-877.WANG Xiaowei,YAO Yao,LIU Wenqing,et al.Application of wave equation prestack migration in carbonate imaging[J].Natural Gas Geoscience,2011,22(5):874-877.
[16]
袁刚,冯心远,蒋波,等.约束层析反演及其在地震速度计算中的应用[J].石油物探,2013,52(1):55-59.YUAN Gang,FENG Xinyuan,JIANG Bo,et al.Constrained tomography inversion and its application in seismic velocity computation[J].Geophysical Prospecting for Petroleum,2013,52(1):55-59.
[17]
杨午阳,张厚柱,撒利明,等.逆时偏移关键问题探讨[J].石油地球物理勘探,2016,51(6):1251-1262.YANG Wuyang,ZHANG Houzhu,SA Liming,et al.Some issues about reverse time migration[J].Oil Geophysical Prospecting,2016,51(6):1251-1262.
[18]
肖艳玲,范旭,王晓涛,等.网格层析速度反演技术在齐古背斜叠前深度偏移中的应用[J].石油地球物理勘探,2017,52(增刊2):98-103.XIAO Yanling,FAN Xu,WANG Xiaotao,et al.Mesh tomographic velocity inversion for the prestack depth migration of the Qigu anticline[J].Oil Geophysical Prospecting,2017,52(S2):98-103.
[19]
王兆旗,叶月明,庄锡进,等.层控网格层析速度建模技术在陆上盐丘区的应用[J].天然气地球科学,2016,27(11):2070-2076.WANG Zhaoqi,YE Yueming,ZHUANG Xijin,et al.Application of layer-constrained grid tomographic velocity modeling in onshore salt domes area[J].Natural Gas Geoscience,2016,27(11):2070-2076.
