渤海A油田上覆砾岩对下伏储层的地震响应特征影响分析及对策

渤海A油田的东营组储层受局部上覆馆陶组砾岩的影响,致其地震响应变弱,严重影响储层真实范围的识别.为此,本文首先从地震波传播理论出发,对上覆砾岩的透射、散射及干涉的影响分析,并形成影响程度定量分析量板.其次基于正演模拟,开展储层地震反射的影响机理及程度分析,分析不同组合结构的砾岩即单层砾岩和多层砾岩,对储层的振幅影响程度,描述砾岩及振幅发生畸变的储层的平面展布形态;分析认为砾岩的厚度对振幅的屏蔽影响程度小于层数的.然后提出基于相控的透射恢复技术,即利用量板分别计算出单层砾岩和多层砾岩所造成的振幅损失程度,据此建立差异化的振幅补偿因子,定量消除上覆砾岩对储层地震响应的影响,完成储层振幅的定量恢复,刻画储层的真实平面范围.最终获得钻井成功,充分证明了本次研究的有效性,实现精确预测潜力区域,以达到储量增加的目的.

Influence analysis and countermeasures on seismic response characteristics of overlying conglomerate to underlying reservoir in Bohai A oilfield

In Bohai A oilfield,the reservoir of Dongying Formation is affected by the local conglomerate of Guantao formation,which makes its seismic response weak and seriously affects the identification of the true range of the reservoir.Therefore,based on the theory of seismic wave propagation,this paper analyzes the influence of transmission,scattering and interference of overlying conglomerate,and forms a quantitative analysis scale of influence degree.Secondly,based on forward modeling,the influence mechanism and degree of seismic reflection of reservoir are analyzed,and the influence degree of conglomerate with different structure,i.e.single-layer conglomerate and multi-layer conglomerate,on the amplitude of reservoir is analyzed,and the plane distribution form of conglomerate and reservoir with amplitude distortion is described;The analysis shows that the thickness of conglomerate has less influence on amplitude shielding than the number of layers.And then,the transmission recovery technology based on phase control is proposed,that is,the amplitude loss degree caused by single-layer conglomerate and multi-layer conglomerate is calculated by using the measuring plate,and then the differential amplitude compensation factor is established to eliminate the impact of overlying conglomerate on the seismic response of the reservoir,and the quantitative recovery of the reservoir vibration amplitude is completed,and the real plane range of the reservoir is depicted.Finally,the successful drilling proved the effectiveness of this study,the potential area can be accurately predicted.Achieve the goal of increasing reserves and adjusting the number of wells.