有机质孔隙对页岩气流动能力影响研究

发布时间：2018-03-07 02:04

本文选题：页岩气　切入点：运移机制　出处：《中国科学:物理学力学天文学》2017年09期 　论文类型：期刊论文

【摘要】：页岩中存在有机质孔隙和无机质孔隙,目前页岩气表观渗透率模型忽略了孔隙类型、孔隙半径分布对气体流动能力的影响.本文基于页岩二维剖光扫描电镜图像数值重建页岩三维数字岩心,并提取孔隙相中轴拓扑结构.根据地质上对有机质孔隙空间分布、有机质孔隙和无机质孔隙半径分布的认识,在对应孔隙喉道位置,充填满足对应孔隙半径分布以及空间分布关系的有机质孔隙和无机质孔隙,建立3种不同有机质孔隙分布模式的页岩孔隙网络模型:有机质孔隙条带状分布、有机质孔隙连片分布、有机质孔隙分散在无机质孔隙中.有机质孔隙中气体流动考虑吸附解吸、表面扩散、黏性流、努森扩散,无机质孔隙中气体流动考虑黏性流、努森扩散,气体性质计算考虑真实气体效应以及在微纳米孔道中相态变化.结果表明,当有机质孔隙半径分布小于无机质孔隙半径分布,有机质孔隙成条带状分布模型气体流动能力最强,有机质孔隙连片分布模型气体流动能力最弱.当有机质孔隙半径分布大于无机质孔隙半径分布,有机质孔隙成条带状分布模型气体流动能力最强,有机质孔隙分散在无机质孔隙模型气体流动能力最弱.本文的研究对认识页岩气流动能力具有显著意义.
[Abstract]:There are organic and inorganic pores in shale, and the pore types are neglected in the present model of apparent permeability of shale gas. The effect of pore radius distribution on gas flow capacity. In this paper, the three-dimensional digital core of shale is reconstructed numerically based on two-dimensional scanning electron microscope (SEM) images of shale, and the axial topological structure of pore facies is extracted. According to the understanding of the distribution of pore radius of organic matter and inorganic material, the pore and inorganic pore of organic matter are filled in the corresponding pore throat, which satisfies the distribution of pore radius and space distribution of organic matter and inorganic pore. Three kinds of shale pore network models with different pore distribution patterns of organic matter were established: the strip distribution of organic matter pores, the distribution of organic matter pores, and the distribution of organic matter pores. Organic pore is dispersed in inorganic pore. Gas flow in organic pore considers adsorption and desorption, surface diffusion, viscous flow, Knudsen diffusion, gas flow in inorganic pore considering viscous flow, Kucson diffusion. The results show that when the distribution of pore radius of organic matter is smaller than that of inorganic pore radius, the gas flow capacity of the model is strongest when the distribution of pore radius is smaller than that of inorganic pore radius. When the distribution of pore radius of organic matter is larger than the distribution of pore radius of inorganic matter, the gas flow ability of the model with strip distribution of organic pores is the strongest. The porosity of organic matter dispersed in the inorganic pore model is the weakest in the gas flow capacity. The study in this paper has significant significance in understanding the shale gas flow capacity.
【作者单位】：中国石油大学(华东)石油工程学院;中国石化油田勘探开发事业部;
【基金】：国家自然科学基金(编号:51490654,51234007,51504276,51504277) 高等学校学科创新引智计划(编号:B08028) 山东省自然科学基金(编号:ZR2014EEP018,ZR2014EL016,ZR2014EL017) 国家油气重大专项(编号:2016ZX05061) 中国石油大学(华东)研究生创新工程(编号:YCX2017019)资助项目
【分类号】：P618.13

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