城市三维地震资料处理浅层成像关键技术

The key technology of shallow imaging in urban 3D seismic data processing

浅层三维地震勘探数据量大、偏移归位准确、横向分辨率高,能够克服二维地震勘探在城市中受障碍物限制致使测线布设与构造走向斜交,浅层小构造控制程度较差和断层归位不够准确等问题。因此浅层三维地震探测可以为城市地下空间探查、活动断裂探测和地质灾害勘查等方面提供更高质量的数据。然而城市三维地震勘探面临表层速度分布不均匀、环境干扰大和障碍物多导致炮点分布不均匀等影响浅层成像的问题。本文以实际三维地震资料为例,针对城市三维地震资料的特点,采用了层析静校正、叠前多方法组合去噪、叠前数据规则化插值和精细动校拉伸切除等技术手段对城市三维地震资料进行处理,提高了浅层成像质量。

The shallow 3 D seismic reflection exploration has a large amount of data,accurate migration,and high lateral resolution.It can overcome some difficulties of the 2 D seismic exploration in the city caused by the obstacles,such as obliquely intersection of the survey line with the structural strike,poor shallow structure detecting,and inaccurate fault locating.Therefore,shallow 3 D seismic exploration can provide higher-quality data for urban underground space exploration,active fault detection,and geological disaster prospecting.However,urban 3 D seismic exploration faces some challenges of shallow imaging,such as inhomogeneity of surface velocity,strong environmental noise,and uneven distribution of shot points caused by obstacles.To improve shallow imaging,tomographic static correction,pre-stack multi-method combination denoising,regularized interpolation of pre-stack data,and combined normal moveout strength cutting.The result shows our processing can improve the quality of shallow imaging of 3 D seismic data.