精细地震成像技术在昆北地区的应用

Application of fine seismic imaging technologies in Kunbei area

昆北地区油气资源丰富,勘探程度低,由于断裂系统发育、噪声干扰严重、地表条件及地下构造复杂(双复杂)等,原始地震资料品质差、静校正问题严重、构建准确速度建模难度大,导致昆北断裂带准确地震成像困难。为此,依托GeoEast处理系统,通过应用菲涅尔层析静校正和反射波超级道剩余静校正等技术,解决严重的静校正问题;通过组合应用多种叠前去噪技术,逐步压制噪声,在保护有效反射信号的同时提高信噪比;结合地质认识和已钻井等信息,通过井控、层控精细速度分析技术构建高精度偏移速度模型,改善了地震成像质量。最终地震成果构造形态落实、断层断点归位准确,高品质成果资料为综合地质研究提供了可靠的地震数据支撑。

The Kunbei area has abundant oil and gas resources with low exploration degrees.However,the developed fault systems,serious noise interference,and complex surface conditions and underground structures(dual complexity)result in the poor quality of original seismic data,serious static correction problems,and great difficulty in accurate velocity modeling,ultimately leading to considerable difficulty in fine seismic imaging in the Kunbei fault thrust belt.Relying on the GeoEast processing system,this study solves the various problems mentioned above.Specifically,serious static correction problems are solved by Fresnel tomographic static correction and reflection-based super-trace residual static correction;noise is suppressed step by step by applying a variety of prestack denoising techniques to enhance the signal-to-noise ratio(SNR)on the premise of protecting the effective reflected signal;with geological knowledge and information on drilled wells,a high-precision migration velocity model is built with well-controlled or layer-controlled fine velocity analysis technique to improve the quality of seismic imaging.The final seismic results reveal accurate determination of the structural morphology and accurate location of the fault and the breakpoints.The high-quality data from the results provide reliable seismic support for comprehensive geological research.