基于相对波阻抗约束下的地质统计学构建低频模型的研究——以GW区块浅层高速砾岩储层反演为例

Study on the Construction of a Low-Frequency Model Based on Geostatistics Under Constrained Relative Acoustic Impedance: Taking the Inversion for High-Velocity Conglomerate Reservoirs in Shallow Layer of GW Block as an Example

摘要:

为提高低幅度构造储层圈闭识别和储层预测精度,提出了一种运用相对波阻抗结合地质统计学方法构建低频模型的新方法。该方法利用地震数据提取地层相对波阻抗信息,将其作为低频模型的约束条件,采用协同克里金插值和序贯高斯模拟等地质统计学方法,基于地质参数的空间相关性和变异特征进行插值优化,进而构建低频模型并开展反演。通过在实际工区的应用,证实了该方法的有效性。研究结果表明:与传统方法相比,该文所构建的低频模型在匹配测井资料、刻画构造形态、预测储层发育等方面具有明显优势,与实际地质情况的吻合度高达85%以上。同时,研究也揭示了方法的局限性,如受地震数据分辨率影响,对薄层预测精度有待提高。

Abstract:

To improve low-amplitude structural reservoir trap identification and reservoir prediction accuracy, a new method of constructing low-frequency model combining constrained relative acoustic impedance with geostatistics is put forward. In this method, relative acoustic impedance information is extracted from seismic data and used as a constraint for the low-frequency model. By employing geostatistical methods such as Kriging interpolation and sequential Gaussian simulation interpolation optimization is performed based on the spatial correlation and variation characteristics of geological parameters. A low-frequency model is subsequently constructed and used for inversion research. The effectiveness of this method is demonstrated through its application in an actual work area. The results show that, compared with traditional methods, the low-frequency model constructed in this study has significant advantages in matching well logging data, depicting structural morphology, and predicting reservoir development. Its agreement with the actual geological conditions is over 85%. Moreover, the present study also reveals the limitations of this method. For example, due to the influence of seismic data resolution, the prediction accuracy for thin layers needs to be improved.