四川盆地页岩储层正演模拟地震响应特征

页岩气的储量巨大且具有低碳环保的优点,具有很大的勘探开发价值,但目前中国页岩气的勘探仍处于初步探索阶段。为了研究页岩气储层的地震响应特征,以四川盆地某气田为研究区,通过设计页岩地层楔状体模型进行声学介质波动方程正演,分别研究页岩储层厚度、地震子波主频及含气性的变化对页岩储层地震响应特征的影响。然后,根据该研究区的实际测井数据和地震资料,建立了连井剖面的二维地质模型,并对其进行声学波动方程正演模拟,最终对研究区储层响应特征进行分析,从而能够初步预测出有利的含气储层,并为验证后续反演结果的准确性提供可靠的依据,对四川盆地及其周围地区页岩储层特征的研究具有一定的指导意义。

Seismic response characteristics of forward modeling of shale reservoirs in Sichuan Basin

With the advantages of huge reserves and low carbon and environmental protection, shale gas has great exploration and development value. However, the exploration of shale gas in China is still in the preliminary stage of exploration. In order to study the seismic response characteristics of shale gas reservoirs, an area of Sichuan Basin was taken as the research area. Firstly, the wedge model of shale formation was designed and its forward modeling with acoustic wave equation method was conducted. The influence of shale reservoir thickness, main frequency of seismic wavelet and gas content on seismic response characteristics of shale reservoir were studied by designing. Then, based on the actual logging data and seismic data in the study area, a two-dimensional geological model of cross-well profile was established and its forward simulation was carried out. Finally, the reservoir response characteristics were analyzed, which could preliminarily predict the favorable gas-bearing areas and provide a reliable basis for verifying the accuracy of the subsequent inversion results. It has certain guiding significance for the study of shale reservoir characteristics in Sichuan Basin and its surrounding areas.