基于全波形反演与走时层析的分步高精度速度建模技术及其在涠洲油田复杂构造成像中的应用  

Step-by-step high-precision velocity modeling technique based on full waveform inversion and traveltime tomography and its application in complex structure imaging of Weizhou Oilfield

作　　者：刘苗[1] 陈琳枝 牛华伟[1] 赵秀莲[1] 李亚清 LIU Miao;CHEN Linzhi;NIU Huawei;ZHAO Xiulian;LI Yaqing(Institute of Exploration and Development,SINOPEC Shanghai Offshore Oil&Gas Company,Shanghai 200120,China)

机构地区：[1]中国石油化工股份有限公司上海海洋油气分公司勘探开发研究院,上海200120

出　　处：《热带海洋学报》2025年第2期178-186,共9页Journal of Tropical Oceanography

摘　　要：南海北部湾涠洲油田构造复杂,断层发育,地层破碎,因此速度结构非均匀性强。为了满足生产要求,该地区进行了多轮走时层析速度建模,包括双方位拖缆数据融合建模,但成像效果较差。全波形反演(full waveform inversion,FWI)利用地震波场的振幅和走时信息构建更准确的速度模型,但通常要求地震数据含有(超)长偏移距成分。针对涠西探区拖缆地震数据偏移距有限的实际情况,文章发展了一种FWI与走时层析的分步高精度速度建模技术流程,先采用从低频到高频的多尺度FWI,由高信噪比的回转波与折射波信号反演浅、中层的速度模型,然后利用反射波走时层析更新深层的速度模型。该项技术应用于涠洲油田复杂构造区域中,处理结果显示:与常规反射波走时层析建模相比,该项技术获得的速度模型精度得以提升,目标区域构造成像效果得到显著改善,断层结构更加清晰,为该油田增储扩产、实现效益开发奠定数据基础。The Weizhou Oilfield in Beibu Bay,South China Sea,has a complex structure,developed faults and fractured strata,resulting in a non-uniform velocity structure.To meet production requirements,this area has undergone multi-round traveltime tomography velocity modeling,including velocity modeling of dual-azimuth streamer seismic data.However,imaging quality remains poor.Full waveform inversion(FWI) builds a more accurate velocity model by making full use of the amplitude and traveltime information of the seismic wavefield.However,this process usually requires that the seismic data contain long offset components.Given the limited offset of streamer seismic data in the Weixi exploration area,this paper develops a high-precision velocity modeling technique process that combines FWI and traveltime tomography.Firstly,multi-scale FWI from low to high frequency is used to invert shallow and intermediate layer velocity models derived from high-SNR turning and refracted wave signals.Reflection traveltime tomography is then used to update the deep-layer velocity model.Compared to conventional reflection traveltime tomography modeling,the accuracy of the velocity model is improved,which in turn improves the structural imaging of the target area,making the fault structure more discernible.This work lays a solid data foundation for the oilfield to increase storage and expand production and realize benefit exploitation.

关 键 词：走时层析 全波形反演 偏移成像 涠洲油田 

分 类 号：P738.4[天文地球—海洋地质]