致密油藏含水条件下二氧化碳与短链烷烃竞争吸附特征的分子模拟  

Molecular simulation of competitive adsorption of CO_(2)and short-chain alkanes under water containing conditions in tight oil reservoirs

作　　者：李静 崔传智[1,2,3,4,5] 于涌博[1,2] 李宗阳 张传宝 张东 LI Jing;CUI Chuanzhi;YU Yongbo;LI Zongyang;ZHANG Chuanbao;ZHANG Dong(College of Petroleum Engineering,China University of Petroleum(East China),Qingdao 266580,China;National Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China),Qingdao 266580,China;Qingdao Key Laboratory of Offshore CO_(2) Geological Storage,Qingdao 266237,China;Qingdao Engineering Research Center of Offshore CO_(2) Geological Storage,Qingdao 266237,China;Shandong Engineering Research Center of Offshore CO_(2) Geological Storage,Qingdao 266237,China;Exploration and Development Research Institute,Shengli Oilfield Company,SINOPEC,Dongying 257015,China)

机构地区：[1]中国石油大学(华东)石油工程学院,青岛266580 [2]深层油气全国重点实验室,中国石油大学(华东),青岛266580 [3]青岛市海洋地质碳封存重点实验室,青岛266237 [4]青岛市海洋地质碳封存工程研究中心,青岛266237 [5]海洋地质碳封存山东省工程研究中心,青岛266237 [6]中国石化胜利油田分公司勘探开发研究院,东营257015

出　　处：《海洋地质前沿》2025年第3期78-88,共11页Marine Geology Frontiers

基　　金：国家自然科学基金“致密油藏多段压裂水平井时空耦合流动模拟及参数优化方法”(51974343)。

摘　　要：致密储层因渗透率低、孔隙度小、微纳米孔隙广泛发育的特点,水驱开发效果差,采用CCUS-EOR技术可以在提高原油采收率的同时实现CO_(2)在油藏的地质封存。目前,关于CO_(2)封存机理的研究一般以咸水层封存机理为主,对致密油藏含水条件下CO_(2)驱油过程中的吸附封存机理研究较少。针对以上问题,本文基于分子模拟方法采用羟基化石英晶胞构建致密油藏孔隙壁面模型,分别建立CO_(2)、原油短链烷烃及水的流体组分模型,研究了含水条件下CO_(2)和原油短链烷烃的竞争吸附特征。结果表明,含水条件下,CO_(2)和CH_(4)、CO_(2)和C_(2)H_(6)竞争吸附时的各组分吸附等温线均符合第I类吸附等温线,CO_(2)的绝对吸附量、过剩吸附量和吸附热均大于CH_(4)和C_(2)H_(6)。CO_(2)和原油短链烷烃在石英壁面的吸附属于物理吸附。模拟条件下,水分子数目对CO_(2)的吸附量影响较大,对CH_(4)的吸附量影响较小。CO_(2)占比增大会使其吸附量增大,使CH_(4)吸附量减少。温度的增大会减少CO_(2)和CH_(4)的绝对吸附量。孔隙尺寸的增大会增加CO_(2)和CH_(4)的绝对吸附量和过剩吸附量。壁面矿物类型对CO_(2)和CH_(4)的吸附量影响较大。Tight reservoirs have low permeability,small porosity,and pervasive micro-nano pores,so water flooding has poor development effects.The use of CCUS-EOR(Carbon Capture,Utilization,and Storage-Enhanced Oil Recovery)technology can realize the geological sequestration of CO_(2)in the reservoir while improving the crude oil recovery efficiency.Currently,research on CO_(2)sequestration mechanisms focuses mainly on saline aquifer sequestration,with less emphasis on adsorption and sequestration during CO_(2)flooding in tight oil reservoirs under water containing conditions.To address the above problems,we established a pore wall model for tight reservoirs using hydroxylated quartz cells based on molecular simulation methods,in which the fluid component models of CO_(2),crude oil short-chain alkanes,and water were contained;and investigated the competitive adsorption characteristics of CO_(2)and crude oil short-chain alkanes under water containing conditions.Results show that under water containing conditions,the adsorption isotherms of each component during the competitive adsorption of CO_(2)and CH_(4),CO_(2)and C_(2)H_(6)were in accordance with the class I adsorption isotherm,and the absolute adsorption amount,excess adsorption amount,and heat adsorption of CO_(2)were larger than those of CH_(4)and C_(2)H_(6).The adsorption of CO_(2)and crude oil short-chain alkanes on the quartz wall was physical.Under simulation conditions,the number of water molecules had a significant impact on the adsorption amount of CO_(2)and a relatively small impact on the adsorption amount of CH_(4).The increase in the proportion of CO_(2)increased CO_(2)adsorption amount but decreased CH_(4)adsorption amount.The increase of temperature reduced the absolute adsorption amount of CO_(2)and CH_(4).The increase of pore size increased the absolute and excess adsorption amounts of both CO_(2)and CH_(4).The type of wall mineral showed a significant impact on the adsorption capacity of CO_(2)and CH_(4).

关 键 词：致密油藏 CO_(2)与短链烷烃 竞争吸附特征 分子模拟 吸附量 

分 类 号：TE357.45[石油与天然气工程—油气田开发工程] P618.13[天文地球—矿床学]