陕北富县黄土塬区三维地震资料处理技术

陕北富县黄土塬侵蚀地貌区地表巨厚的黄土盖层沟壑纵横,高程变化剧烈,复杂的近地表结构、严重的高频吸收衰减和多种类型的干扰波,导致常规处理方法获得的地震资料信噪比和分辨率较低,无法满足后续地震成像处理和储层预测的需求。针对黄土塬区复杂地表静校正难题,提出了"先低频、后中高频,逐步逼近"的静校正思路并取得了明显效果;针对该区噪声类型多、分布范围广的特点,采用"多域联合,先强后弱"的串联去噪配套技术进行叠前高保真噪声衰减;利用保持振幅的一致性处理技术,消除地震资料的振幅、频率差异,统一资料的品质;通过三维地表一致性反褶积和叠后进一步拓宽频带处理,提高地震资料的分辨率。处理结果表明,研究区地震资料的信噪比、分辨率和保真度得到了有效提高。

3D seismic data processing technique for loess tableland area in Fuxian,North Shanxi Province

At erosive loess tableland area in Fuxian,Shanxi Province,the surface is covered by huge loess with vertically and horizontally distributed ravines and gullies.Meanwhile,the surface elevation varies seriously.Complex near-surface structure,serious high-frequency absorption and kinds of interference lead to low signal-to-noise ratio for the seismic data after conventional processing methods,which cannot satisfy the requirements of seismic imaging and reservoir prediction.As for the complex surface static correction problem in loess area,a new static correction idea of "low-frequency first,middle/high-frequency second and successive approximation" is generated and we achieved good results.Aiming at the characteristics of various kinds and broad distribution ranges of noise,cascaded noise attenuation technique of ’multi-domains union,from strong to weak’ is applied to carry out pre-stack high fidelity noise attenuation.The difference of amplitude and frequencies of seismic data is eliminated and the quality of data was unified by making use of amplitude consistency reservation.With 3D surface consistent deconvolution and post stack resolution enhancement processing methods realization,the effective band of seismic signal is expanded and resolution is improved.The processing results show that the signal-to-noise ratio,resolution and fidelity are effectively enhanced.