匹配追踪旁瓣压制方法在四川盆地栖霞组储层识别中的应用

Application of matching pursuit based sidelobe suppression method to reservoir identification of Qixia Formation,Sichuan Basin

在四川盆地中二叠统栖霞组白云岩储层预测中,基于地震资料的"亮点反射"储层识别模式由于地层速度结构的复杂性而存在多解。以四川盆地中部地区环乐山-龙女寺古隆起带,利用二维及三维地震资料,首次应用基于匹配追踪旁瓣压制方法预测四川盆地环古隆起带的栖霞组白云岩储层,刻画环古隆起带栖霞组有利储层发育区。研究结果表明:①栖霞组内部储层地震反射受到下伏地层子波旁瓣叠加的影响,造成地震响应存在假象,古隆起外围区受到栖一段泥晶灰岩、梁山组泥页岩、奥陶系页岩共同产生干涉的影响,造成栖霞组储层地震响应调谐增强,影响程度大于古隆起主体区;②相对于传统地震资料,基于匹配追踪旁瓣压制方法能够有效地消除下伏地层形成的子波旁瓣对于栖霞组储层地震成像的影响,降低了储层识别的多解性,同时,提高了深层储集体的分辨能力。

When predicting some dolomite reservoirs of Middle Permian Qixia Formation,Sichuan Basin,complex stratigraphic velocity structure may cause that a model of"bright spot reflection"reservoir identification based on seismic data has multiple-solution problem.So,the Qixia Formation surrounding paleo-uplift in central Sichuan Basin was taken as an objective.According to 2D and 3D seismic data,the Qixia dolomite reservoirs of around Leshan-Longnvsi paleo-uplift of Sichuan Basin were predicted for the first time by using a method of matching pursuit based sidelobe suppression.Moreover,some favorable reservoir development zones of Qixia Formation in the paleo-uplift were described precisely.Results show that(1)for Qixia reservoirs,the seismic reflection creates an illusion of seismic response due to the impact of wavelet sidelobe super imposition of their underlying strata.In the periphery of paleo-uplift,the response tuning of Qixia reservoirs is enhanced by the joint effect of the micrite of Qixia 1 Member,the mud shale of Liangshan Formation,and the shale of Ordovician,whose in fluence degree is higher than that in the main paleo-uplift;and(2)compared with some traditional seismic processing technologies,this method of matching pursuit based on sidelobe suppression can effectively eliminate the influence of wavelet sidelobe formed by underlying strata on the seismic imaging of Qixia reservoirs,reduce the multiple solution of reservoir identification,and improve an ability to distinguish deeper reservoirss.