山前带地震勘探技术进展与对策研究

Progress and strategy of the seismic exploration in foothill area

地震勘探技术是制约复杂山前构造带油气勘探的瓶颈技术。山前带复杂的表层及地下地质条件,给地震勘探带来了极大挑战,主要表现在地震资料信噪比低;横向速度变化大,地震成像方法不适用;山前带地下复杂构造的准确解释困难。建议采取的技术对策包括:深化对山前带复杂波场的认识;以模型为基础设计宽线大组合二维、宽方位高覆盖三维等观测系统;进一步改善激发、接收效果;探索散射干扰、非纵方向的非线性相干噪声等山前带特殊噪声的压制方法;多方法联合提高静校正效果;研究应用高效的逆时偏移技术,重点研究低信噪比资料速度建模技术;前瞻性地研究起伏地表各向异性逆时偏移、全波形反演等新技术。同时,建议严格采集、处理、解释全过程的质量控制,不断改进单项方法技术的应用效果,持续优化整个地震技术的应用流程,做好地震技术一体化和技术集成,在地质指导下通过综合物探手段提高山前带勘探效果。

Seismic exploration techniques are the bottleneck of hydrocarbon exploration in the complex foothill structural belt.The complex surface and underground geologic conditions bring great challenge for seismic exploration,which mainly displays low S/N of seismic data,large variation in lateral velocity is not suitable to utilize seismic imaging methods,and the complicated underground structures in piedmont zone are difficult to interpret.In order to solve the problems for the seismic exploration in foothill area,we proposed some strategies:①deepening the understanding of complicated wavefield from piedmont zone;②model based designing geometry such as wideline large array 2D,wide-azimuth high-fold 3D;③to further improve shooting and receiving effects;④probing de-noising methods for the particular noise(scattering wave and non-longitude non-linear coherent noise,et al) existing in foothill area;⑤jointly applying multi-methods to improve static correction effect;⑥studying and applying reverse time migration,and focusing on velocity model building technique for low S/N seismic data;⑦prospectively studying new techniques including undulating surface anisotropy reverse time migration and full waveform inversion and so on.Meanwhile,we suggest carrying out strict QC during the whole seismic acquisition,processing and interpretation,constantly improving the application result of single technique,continuously optimize the application workflow of the seismic techniques,emphasis on the integration of seismic technology,and improve the seismic exploration effect by integrated geophysical prospecting means with the guidance of geology.