酸性火山岩储层微观孔隙结构的宏观表征与研究

Macro Characterization and Study of Microscopic Pore Structures of Acidic Volcanic Reservoirs

储层的微观孔隙结构指的是储集岩中孔隙和喉道的几何形状、大小、分布及其相互连通和配比关系。准确掌握储层的孔隙结构信息,搞清楚孔隙结构的差异对储层宏观地球物理特性的影响,对于正确评价储层的储集性能和开采价值具有十分重要的意义。在毛细管束模型基础上,从经典渗透率方程入手,应用函数单调性的分析方法深入剖析了储层宏观物性参数与其微观孔隙结构的内在联系;并针对酸性火山岩储层,应用恒速压汞资料,采用相关分析法表明,储层品质指数是定量表征火山岩储层微观孔隙结构的最佳宏观物性参数;在此基础上,采用频率分布法确定了徐深气田酸性火山岩孔隙结构优劣的宏观判别标准,建立了孔隙结构参数判别图版,并指出了火山岩孔隙结构与砂岩孔隙结构的差别,为宏观地球物理测井资料连续定量表征储层微观孔隙结构、开展酸性火山岩储层测井评价方法研究奠定了基础。

The microscopic pore structure of the reservoirs indicated the geometry,size,distribution and its interconnected relationship of the reservoir rock pores and throats.Accurate knowledge of reservoir pore structural information was of great significance for the correct evaluation of performance and the exploitation value of the reservoir and figuring out the differences of the pore structure on the macroscopic reservoir geophysical characteristics.Based on the model capillary tubes,the internal relations of the macroscopic properties of reservoir parameters and its microscopic pore structure were analyzed starting from the classic permeability equation and by using the monotonicity analysis methods of the function.In allusion to acidic volcanic rock reservoirs,constant mercury data and correlation analysis,the results show that the reservoir quality index is the best macroscopic parameter to characterize reservoir microscopic pore structure.On the basis state above,the frequency distribution method is used to determine the criterion for judging the pore structure in acidic volcanic rocks in Xushen Gasfield and a chart board is established for judging the pore structural parameters,the difference between volcanic pore structure and sandstone structure is pointed out,it provides the foundation for the continuously quantitative characterization of microscopic pore structures by using macroscopic geophysical logging data and carrying out the logging evaluation of acidic volcanic rock reservoirs.