Characterization of Pore Structure and Simulation of Pore-Scale Flow in Tight Sandstone Reservoirs  

作　　者：Min Feng Long Wang Lei Sun Bo Yang Wei Wang Jianning Luo Yan Wang Ping Liu 

机构地区：[1]Petroleum Exploration and Production Research Institute,PetroChina Changqing Oilfield Company,Xi’an,710016,China

出　　处：《Fluid Dynamics & Materials Processing》2025年第3期573-587,共15页流体力学与材料加工(英文)

摘　　要：This study sheds light on how pore structure characteristics and varying dynamic pressure conditions influence the permeability of tight sandstone reservoirs,with a particular focus on the Paleozoic reservoirs in the Qingshimao Gas Field.Using CT scans of natural core samples,a three-dimensional digital core was constructed.The maximum ball method was applied to extract a related pore network model,and the pore structure characteristics of the core samples,such as pore radius,throat radius,pore volume,and coordination number,were quantitatively evaluated.The analysis revealed a normally distributed pore radius,suggesting a high degree of reservoir homogeneity and favorable conditions for a connected pore system.However,it was found that the majority of throat radii measured less than 1μm,which severely restricted fluid flow and diminished permeability.Over 50%of the pores measured under 100μm^(3),further constraining fluid movement.Additionally,30%-50%of the pore network was composed of isolated and blind-end pores,which significantly impaired formation connectivity and reduced permeability.Based on this,the lattice Boltzmann method(LBM)was used for pore-scale flow simulation to investigate the influence mechanism of pore structure characteristics and dynamic-static parameters such as displacement pressure difference on the permeability performance of the considered tight sandstone reservoirs for various pressure gradients(0.1,1,and 10 MPa).The simulations revealed a strong relationship between pressure differential and both the number of streamlines and flow path tortuosity.When the pressure differential increased to 1 MPa,30 streamlines were observed,with a tortuosity factor of 1.5,indicating the opening of additional seepage channels and the creation of increasingly winding flow paths.

关 键 词：Tight sandstone digital core flow simulation lattice Boltzmann method 

分 类 号：TE311[石油与天然气工程—油气田开发工程]