摘要
封存效率是CO_(2)地质封存潜力评估中的关键参数。CO_(2)封存效率主要由CO_(2)羽流运移规律决定,受黏性力、重力、毛管力等力学机制影响。目前在毛管力对CO_(2)羽流运移规律和封存效率影响机理方面的研究并不完善。该文基于垂直平衡假定,推导了考虑毛管力的承压咸水层CO_(2)羽流运移数学模型。模型表明CO_(2)羽流运移规律由无量纲毛管力数、Bond数、流度比、毛管力-饱和度函数及相对渗透率-饱和度函数共同决定。通过数值模拟求解数学模型,揭示了毛管力对CO_(2)封存效率的影响机理。结论如下:(1)毛管力与黏性力的相互作用在水平方向上产生气饱和度过渡区,使得CO_(2)羽流前缘远离注入井,封存效率降低;(2)毛管力与重力的相互作用在垂直方向上产生气饱和度过渡区,使得CO_(2)上浮速度变慢,CO_(2)羽流前缘靠近注入井,封存效率提高;(3)在实际项目条件下,毛管力与重力的相互作用占主导,高毛管力下封存效率可达无毛管力情况下的2~4倍。
Storage efficiency is a key parameter for CO_(2) storage capacity estimation.Storage efficiency is mainly determined by the mechanism of CO_(2) plume migration,which is influenced by the viscous,gravity and capillary force.The impact of capillary force on CO_(2) plume migration and storage efficiency has not been well explored by previous studies.In this study,a mathematical model of CO_(2) plume migration honoring the capillary force is derived based on vertical equilibrium assumption.The model indicates that plume migration is governed by the dimensionless capillary number,Bond number,mobility ratio,capillary pressure-saturation and relative permeability-saturation relationships.Numerical simulations are conducted to investigate the impact of capillary pressure on CO_(2) storage efficiency.These conclusions can be drawn from the results:①The interplay between viscous and capillary force creates a horizontal capillary fringe.This effect causes the plume to migrate farther from the injection well,leading to an inferior storage efficiency.②The interplay between capillary and gravity force slows down the ascent of CO_(2) and creates a vertical capillary fringe.This effect causes the plume to stay closer to the injection well,resulting in a superior storage efficiency.③Under typical conditions in geological CO_(2) storage projects,the capillary-gravity interplay dominates,and the storage efficiency under high capillary conditions can be 2 to 4 times that of scenarios without capillary effects.
作者
宋世瀚
高冉
王锐
SONG Shihan;GAO Ran;WANG Rui(Petroleum Exploration and Production Research Institute Limited Company,SINOPEC,Beijing 102206)
出处
《中国煤炭地质》
2025年第12期24-32,59,共10页
Coal Geology of China
基金
深地国家科技重大专项“油气藏地质体CO_(2)封存状态表征及有效封存量评价研究”(2024ZD1004302)
中国石化科技攻关项目“咸水层CO_(2)封存运移规律及调控方法研究”(P23067)。
关键词
CO_(2)地质封存
封存效率
羽流运移
量纲分析
毛管力
CO_(2)geologic storage
storage efficiency
plume migration
dimensional analysis
capillary force
