纳米颗粒对原油-CO_(2)体系界面张力的影响  

Effect of nanoparticles on interfacial tension of crude oil‑CO_(2) system

作　　者：林魂 袁勇 赖向东 董明达 LIN Hun;YUAN Yong;LAI Xiangdong;DONG Mingda(School of Safety Engineering,Chongqing University of Science&Technology,Chongqing 401331,China;National-Local Joint Engineering Research Center for Shale Gas Exploration and Development,Chongqing 401120,China;Key Laboratory of Shale Gas Exploration,Ministry of Natural Resources,Chongqing 401120,China;CNPC Well Control Emergency Rescue Response Center,Guanghan 618300,China)

机构地区：[1]重庆科技学院安全工程学院,重庆401331 [2]页岩气勘探开发国家地方联合工程研究中心,重庆401120 [3]自然资源部页岩气资源勘查重点实验室,重庆401120 [4]中国石油井控应急救援响应中心,四川广汉618300

出　　处：《大庆石油地质与开发》2023年第3期99-106,共8页Petroleum Geology & Oilfield Development in Daqing

基　　金：重庆市自然科学基金面上项目“考虑化学渗透压的页岩储层压裂液渗吸机理与模型研究”(cstc2019jcyj-msxmX0457);重庆市教委科学技术研究项目“致密油藏CO_(2)吞吐排驱机理及影响因素研究”(KJQN202001508)。

摘　　要：注CO_(2)开发含沥青质油藏会导致沥青质沉淀,造成储层堵塞,而注入纳米颗粒能够有效抑制沥青质沉淀。在明确原油注CO_(2)产生沥青质沉淀特征的基础上,选取不同地区4种沥青质质量分数的原油,分别测定了无机纳米颗粒SiO_(2)、金属氧化物纳米颗粒Co_(3)O_(4)和Fe_(3)O_(4)作用下的CO_(2)与原油的界面张力,并评价了原油性质对纳米颗粒性能的影响。结果表明:原油中沥青质沉淀量随压力的增加而增大,CO_(2)与原油间界面张力随压力的增加呈现出先快速下降后逐渐变缓的趋势,对应的一次接触最小混相压力也随沥青质沉淀量的增加而增大;纳米颗粒具有较高的表面活性和比表面积,能够吸附沥青质颗粒,抑制沥青质聚集,有效降低油气体系界面张力,其中纳米颗粒性能高低依次为无机纳米颗粒SiO_(2)、金属氧化物纳米颗粒Co_(3)O_(4)和Fe_(3)O_(4);纳米颗粒性能随原油黏度和沥青质质量分数的增加而变好,随原油中硫质量分数的增加而变差。研究成果为改善CO_(2)驱替效果和抑制沥青质沉淀提供了参考和借鉴。Asphaltene precipitation can be induced by CO_(2) injection in asphaltene-bearing reservoir,causing reservoir blocked,while precipitation can be effectively inhibited by injection of nanoparticles.Based on clarifying precipitation characteristics of asphaltene in crude oil injected by CO_(2),crude oil with 4 asphaltenes mass fractions are chosen from different blocks,interfacial tensions between CO_(2) and crude oil under actions of inorganic nanoparticle SiO_(2) and metal oxide nanoparticles Co_(3)O_(4) and Fe_(3)O_(4) are measured respectively,and influences of crude oil properties on performances of nanoparticles are evaluated.The results show that the increase of asphaltene precipitation amount in crude oil with pressure increase leads to the trend of interfacial tension between CO_(2) and the crude oil decreasing rapidly at first and then slowing down gradually with pressure increase,and corresponding first contact minimum miscibility pressure also increases with asphaltene precipitation increase.Nanoparticles have high surface activity and specific surface area,which can adsorb asphaltene particles,inhibit asphaltene aggregation and effectively reduce interfacial tension of oil-gas system.Performances of nanoparticles are ranked in the order of inorganic nanoparticle SiO_(2),metal oxide nanoparticles Co_(3)O_(4) and Fe_(3)O_(4).Performances of nanoparticles increase with increase of crude oil viscosity and asphaltene mass fraction,and decrease with increase of sulfur mass fraction in crude oil.The research provides references for improving CO_(2) displacement effect and inhibiting asphaltene precipitation.

关 键 词：注CO_(2) 沥青质沉淀 纳米颗粒 界面张力 最小混相压力 

分 类 号：TE349[石油与天然气工程—油气田开发工程]