全波形反演在超深海盐下碳酸岩油气藏中的应用研究

Studies on FWI in pre-salt carbonate reservoir of ultra-deep water

超深海油气藏是近期全球勘探热点和新发现重点领域,同期巴西盐下碳酸岩油气藏勘探取得重要突破.为提高超深海盐下碳酸岩油气藏地震资料品质,本文引入全波形反演(FWI)技术,该技术利用叠前地震波场的运动学和动力学信息重建复杂地质背景下构造的细节和岩性信息,提升速度建模精度.同时为建立高精度速度模型和提高计算效率,引入三维广义SRME和高精度层析成像技术,利用VTI和TTI全波形反演技术逐步建立高精度速度模型.对比分析,基于FWI速度模型的偏移结果信噪比高,波阻连续性好,地层反射特征清晰,与实钻结果吻合度高,勘探成功率高,助推十亿吨级石油地质储量的落实,降低勘探风险,推动超深海盐下碳酸岩油气藏的勘探开发.

Recently the ultra-deep water reservoir has been the paramount exploration region that many new oil and gas discoveries arose. Meanwhile,the most important breakthrough occurred in presalt carbonate reservoir in Brazil. Full-waveform inversion（ FWI） is applied to enhance seismic quality in this study,where the dynamic and kinematic information of pre-seismic wave fieldis applied to improve the precision of velocity model with complex geological structure. In order to achieve this target,VTI and TTI FWI methods mixed with 3D General SRME and high-precision tomography imaging have been fully applied. Comparing the advantages,the migration based on FWI coincides with the actual drilling results has high S / N,good impedance continuity,clear seismic reflection. The results applied widely has improved the rate of exploration success,proved one billion geological reservoir and will prompt the exploration and development of pre-salt carbonate reservoir in ultradeep water.