超深水区基准面延拓驱动的反射波形反演成像  

Reflection waveform inversion imaging driven by redatuming in ultra⁃deepwater area

作　　者：王璇 王腾飞[1,2] 程玖兵[1,2] 武泗海 朱峰 刘玉柱[1,2] WANG Xuan;WANG Tengfei;CHENG Jiubing;WU Sihai;ZHU Feng;LIU Yuzhu(School of Ocean and Earth Science,Tongji University,Shanghai 200092,China;State Key Laboratory of Marine Geology,Shanghai 200092,China)

机构地区：[1]同济大学海洋与地球科学学院,上海200092 [2]海洋地质国家重点实验室,上海200092

出　　处：《石油地球物理勘探》2024年第4期790-799,共10页Oil Geophysical Prospecting

基　　金：国家自然科学基金项目“基于P/S模式解耦与海森算子的弹性反射波形反演方法及其应用”(42074157);“OBS主动源深反射地震方法及其在荔湾凹陷构造研究中的应用”(41930105);“二阶随机优化弹性反射波形反演方法研究”(42204110);上海市自然科学基金项目“东海海底多分量数据智能P/S分离及二阶优化波形反演”(22ZR1465200)联合资助。

摘　　要：远离大陆架的海洋油气勘探与开发具有高风险、高投入的特征,对构造成像和储层预测精度要求很高,传统的基于射线理论的速度建模方法难以满足精细成像的需求。超深水探区地震观测受巨厚水层的影响,导致记录时间较长、数据规模和模型空间巨大,因此难以大规模应用基于波动理论的速度建模方法。为此,提出基准面延拓驱动的反射波形反演成像技术。该技术利用基准面延拓剥离水层影响,消除地震波在水中的传播效应,降低数据规模、压缩模型空间、缓解速度—深度多解性,使全波形反演在深海区的实际应用成为可能。考虑到超深水探区有限炮检距难以记录到穿透较深的初至波,无法利用初至波进行波形反演更新速度,因此选用反射波形反演对延拓后数据进行速度建模,以便得到高精度速度模型和成像结果。理论模型合成数据和南海A区块实际数据处理结果表明,该技术能够大规模缩减数据量,并提高高精度速度建模的效率,可在超深水油气勘探中发挥积极作用。Offshore petroleum exploration beyond the continental shelf is characterized by high risk and substan⁃tial investment,necessitating high precision in structural imaging and reservoir prediction.Traditional velocity modeling method based on ray theory often fails to meet the demands for fine imaging.In ultra⁃deepwater explo⁃ration,seismic observations are challenged by the thick seawater layer,resulting in extended recording times and immense data and model spaces,making large⁃scale application of wave theory⁃based velocity modeling dif⁃ficult.To address this,this paper proposes a reflection waveform inversion imaging technology driven by reda⁃tuming.This technology mitigates the seismic wave propagation effects in the seawater layer,reducing data vol⁃ume,compressing model space,and alleviating velocity⁃depth ambiguity,thereby enabling the practical applica⁃tion of full waveform inversion in deep⁃sea environments.Due to the limited detection distance in ultra⁃deepwa⁃ter area,recording the first arrival wave with sufficient depth penetration is challenging,preventing its use in waveform inversion for velocity updates.Consequently,this paper employ reflection waveform inversion for the redatumed data to achieve a high⁃precision velocity model and imaging results.Synthetic data from theoretical models and actual data processing results from Block A in the South China Sea demonstrate that this technology significantly reduces data volume and enhances the efficiency of high⁃precision velocity modeling.It holds promising potential for improving ultra⁃deepwater oil and gas exploration.

关 键 词：超深水 拖缆 基准面延拓 反射波形反演 逆时偏移 速度建模 

分 类 号：P631[天文地球—地质矿产勘探]