基于孔隙网络模型的碳酸盐岩岩心跨尺度分析

Cross-scale Analysis of Carbonate Rock Cores Based on Pore Network Model

现有微观孔隙结构研究手段多局限于在微尺度提供孔喉尺寸、孔喉比等孔隙结构参数,所得结果无法直接应用于岩心尺度及矿场尺度等宏观尺度的研究中,其研究结果与储层实际结合具有一定困难。为此,从多尺度评价角度出发,以碳酸盐岩岩心数据体为研究对象建立孔隙网络模型分析碳酸盐岩微观孔隙结构,在此基础上,根据分布函数及分形函数对其进行尺度升级,获得岩心尺度评价参数。结果表明:尺度升级后的岩心表现出明显低渗、致密特性,与孔隙网络模型分析结果相符。可见,对微观孔隙结构分析结果进行尺度升级具有一定可行性,并且升级结果对于宏观尺度的评价工作具有一定的理论意义。

The existing research methods for micro pore structure are mostly confined in providing structural parameters including the sizes of pores and throats,and the pore throat ratio,etc.at micro scale.The results obtained by those methods cannot be directly applied to the research on macro scale such as core scale and field scale,and they are usually difficult to be combined with the actual reservoir situation.In light of this,a pore network model was established to analyze the microscopic pore structure of carbonate rock with carbonate core data as the research object from the perspective of multi-scale evaluation.On this basis,the scale of the core was upscaled for further evaluation based on the distribution function and fractal function,and the evaluation parameters at core scale were thereby obtained.The results show that the upscaled core exhibits obvious low permeability and density,which is consistent with the analysis results of pore network model.Therefore,it is feasible to upscale the micro pore structure analysis result,and the upscaled results have a certain theoretical significance for the evaluation at macro scale.