叠前AVA同时反演的道集优化处理及应用效果

Gather optimal processing and application effect of prestack AVA instantaneous inversion

叠前AVA同时反演技术已在岩性预测和流体检测中广泛应用,其预测效果除了受反演方法本身影响外,最重要的是受到CRP道集数据质量的影响。地震勘探虽然已从构造勘探为主向构造勘探和岩性勘探并重转变,但目前地震成像仍以构造成像为主,很少为地震储层描述进行保持动力学特征的处理,尤其是对叠前弹性参数反演需要的CRP道集数据。文中从叠前AVA同时反演应用效果出发,针对CRP道集,重点考虑叠前去噪、道集拉平及剩余能量补偿等3个方面,提出了叠前CRP道集优化处理方法及流程。从正演道集、AVO子波、信噪比、反演残差等方面分析道集优化处理效果,及其对叠前反演的影响。海-塔盆地TN地区叠前AVA同时反演实例证明,道集优化处理提高了CRP道集数据质量,反演精度得到提高。储层预测结果表明,质量较差的CRP道集数据将会在叠前反演中引入较大误差,从而影响反演的储层预测效果。

Prestack AVA instantaneous inversion has an extensive application in the lithology prediction and hydrocarbon predietion, its accuracy can be easily affectcd by inversion algorithms as well as much sensitive to the quality of input data. Although seismic exploration has achieved its transition from mainly focus on structure exploration to both structure exploration and lithology exploration, seismic image is still mostly structural imaging at present. It is uncommon to remain dynamic charaeteristics during the processing with the purpose of seismic reservoir description, and even less to supply the ideal CRP gather which ean meet the need of prestaek elastic parameters inversion. Based on the application effect of prestack AVA instantaneous inversion, aiming at CRP gather, prestack noise removing, gather flattening and residual energy compensation are focally considered. Methods and processes of prestack CRP gather optimal processing are put torward. The processing effect of gather optimal processing and the effect of the processing on prestack inversion are analyzed from aspects of forward gather, AVO wavelet, signal-nnise ratio and inversion residual error. The ease history of prestack AVA instantaneous inversion in TN Area of Halaer-Tamtsag Basin has verified that the gather optimal processing improves the CRP gather data quality aud the inversion accuracy is improved. Reservoir prediction results show that the CRP gather data of poor-quality CRP gather data will result in a great error in prestack inversion, which affects the reservoir prediction effect of inversion.