叠前反演数据优化处理技术

叠前反演技术已逐步成为寻找岩性油气藏的主要工具。但是，目前叠前反演前对地震数据进行预处理的技术及流程大都仍然采用常规处理中的思路与方法，而常规处理中产生的剩余时差和残余噪声将直接影响反演结果的精度，因而需要对叠前反演数据进行优化处理。分析了剩余时差和残余噪声的产生原因，选用常规多项式拟合及叠加技术确定记录道上每一时刻信息的正确位置，应用静态时移的方法消除剩余时差;采用多道识别、单道消除的横向滑动时空变小波阈值去噪方法，消除残余噪声产生的根源，保证去噪结果具有更高的保真度。理论模型试算和实际地震资料处理结果证明了叠前反演数据优化的必要性以及所论优化处理技术的正确性。

The prestack inversion technology has become the main tool for lithological reservoir exploration.However,the seismic data before the prestack inversion are processed still in conventional pre-processing technology and workflow.The residual moveout and residual noise caused by conventional processing will directly affect inversion accuracy.Thus the data optimization processing before the prestack inversion is imperative.In this paper we analyze the causes of residual moveout and residual noise,the conventional polynomial fitting and stack technique is used to locate the correct position of seismic response in record traces for every moments and the residual moveout is eliminated by static shift.By using the time-space-varying wavelet threshold denoising technique based on the horizontal sliding for multi-channel identification and single elimination,we eliminate the root causes of residual noise to make sure the higher fidelity of denoising result.The theoretical model and actual data processing results show the necessity and validity of data optimization processing before the prestack inversion.