普光气田礁滩相复杂孔隙类型储集层渗透率地震预测方法*

礁滩相碳酸盐岩储集层孔隙类型多样,孔—渗关系复杂,由于缺少相应的岩石物理模型,储集层渗透率地震预测一直是一个难题。作者以普光气田为例,通过分析复杂孔隙类型对储集层渗透率的控制作用及不同孔隙类型储集层在常规测井和声学测井上的响应特征,引入反映孔隙形态和连通性的 “孔构参数”表征相似孔隙度样品的岩石物理参数变化;进而建立基于孔构参数的孔隙类型判别标准和不同孔隙类型储集层孔—渗关系模型,对储集层测井渗透率进行精细解释和评价;并通过分析不同孔隙类型储集层的弹性参数与孔构参数的关系,建立起基于孔构参数的岩石物理量版;采用叠前统计学反演方法首先开展孔隙度、孔构参数的地震反演,进一步开展基于孔隙度和孔构参数的渗透率地震反演,实现了复杂孔隙类型储集层渗透率的定量预测。

Seismic prediction method of permeability of reef bank reservoir with complex pore types in Puguang Gasfield

The reef bank carbonate reservoirs are characterized by various pore types and complex relationship between porosity and permeability. Due to the lack of corresponding rock physics models,seismic prediction of reservoir permeability has been a difficult problem for a long time. Taking Puguang Gasfield as an example,the controlling effect of complex pore types on reservoir permeability and logging response characteristics of different pore types are analyzed,and frame flexibility factor is introduced in this paper to characterize the rock physical parameters variation of samples with similar porosity. In order to make fine interpretation and evaluation of reservoir logging permeability,the discrimination standard of reservoir pore types and reservoir porosity-permeability model are established based on the frame flexibility factor. Rock physical model based on the frame flexibility factor is finally established by analyzing the relationship between elastic parameters of reservoirs with various pore types and the frame flexibility factor. Quantitative prediction of reservoir permeability with complex pore types is realized by pre-stack geostatistical inversion of permeability based on porosity and the frame flexibility factor.