Phase Behavior and Dew Point Pressure of Multicomponent Condensate Gas in Nanopores  

作　　者：Jichao Zhao Xu Yan Jing Sun Sheng Li 

机构地区：[1]Petroleum Engineering College,Yangtze University,Wuhan,430199,China [2]Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering(Yangtze University),Wuhan,430199,China [3]Exploration&Development Project Department of Mahu Area of Xinjiang Oilfield Company,China National Petroleum Corporation,Karamay,834000,China

出　　处：《Fluid Dynamics & Materials Processing》2025年第2期279-292,共14页流体力学与材料加工(英文)

基　　金：financially supported by the Hubei Province Education Department of China(Project Name:Research on the Formation Mechanism and Microscopic Characteristics of Tight Dolomite Reservoirs in Salt Lake Basins:A Case Study of the Xingouzui Formation in the Jianghan Basin,Grant No.B2020032).

摘　　要：Shale gas reservoirs typically contain numerous nanoscale pores,with pore size playing a significant role in influencing the gas behavior.To better understand the related mechanisms,this study employs the Gauge-GEMC molecular simulation method to systematically analyze the effects of various pore sizes(5,10,20,and 40 nm)on the phase behavior and dew point pressure of the shale gas reservoir components.The simulation results reveal that when pore sizes are smaller than 40 nm,the dew point pressure increases significantly as the pore size decreases.For instance,the dew point pressure in 5 nmpores is 20.3%higher than undermacroscopic conditions.Additionally,larger hydrocarbon molecules exhibit a tendency to aggregate in smaller pores,particularly in the 5–10 nm range,where the relative concentration of heavy hydrocarbons(C_(4+))increases markedly.Moreover,as the pore size becomes larger,the component distribution gradually aligns with experimental results observed under macroscopic conditions.This study demonstrates that pore effects are more pronounced for smaller sizes,directly influencing the aggregation of heavy hydrocarbons and the rise in dew point pressure.These phenomena could significantly impact the diffusivity of shale gas reservoirs and the recovery of condensate gas.The findings provide new theoretical insights into phase behavior changes in nanopores,offering valuable guidance for optimizing shale gas reservoir extraction strategies.

关 键 词：Condensate gas NANOPORES molecular simulation dew point pressure confinement effect 

分 类 号：TE343[石油与天然气工程—油气田开发工程]