地震重构反演在大庆长垣剩余油预测中的应用

Application of seismic reconstruction inversion in remaining oil prediction of Daqing Placantieline

在大庆长垣G地区P油层重构反演中,利用波阻抗的低频分量和自然电位的高频分量,融合、重构了拟波阻抗曲线,开展了约束稀疏脉冲反演、特征参数重构反演以及反演后处理工作,拓宽了地震频带的重构反演方法,极大提高了地震反演的分辨率,较好地界定了砂体对接关系及其储层空间展布特征。研究结果表明:纵向上不仅能够识别出大于5 m的厚砂层,而且能够识别出约2 m的薄砂层;砂体呈窄条带状断续分布。研究区储层平面、层间矛盾突出,不同相带吸水变化较大,间歇性吸水,甚至不吸水,数值模拟研究表明,剩余油主要集中在油田边部储层及井间河道砂。该研究充分挖掘了地震资料的潜力,对已开发油田的构造和储层进行了再认识,进一步落实了储层分布特征和剩余油潜力。

This paper reconstructs the pseudo-acoustic curve by fusing the low-requency component of wave impedance curves and the high frequency components of spontaneous potential and taking the reconstruction inversion of P reservoir in G Alea of Daqing Placanticline as an example. The constrained sparse spike inversion, the characteristic parameter reconstruction inversion and the processing after inversion are carried out. By broadening the reconstruction of seismic frequency band inversion method, the resolution of the seismic inversion can be improved, the docking relationship of sand body and its distributing feature of the reservoir space are better defined. Study results show that the sandstone more than 5 m and the thin sandstone about 2 m can be cognized longitudinally. Sand body is in narrow banded and distributes discretely, so the heterogeneity becomes more prominent in the plane and interlayer. Water absorption greatly changes in the different facies belt, appearing intermittent water absorption, even no water. Numerical simulation study shows that the remaining oil mainly concentrates in the reservoirs of oilfield edge and the cross-well channel sand, and the space of remaining oil increases. This study fully taps the potential of seismic data and reunderstands the structure and reservoir of developed oilfields. The reservoir distribution characteristics and the remaining oil potential are further defined.