注CO2对延长化子坪原油物性的影响  

Effect of CO2 Injection on Physical Properties of Huaziping Crude Oil in Yanchang Oilfiled

作　　者：张忠林 王伟[1,2] 赵习森 王世玉 黄春霞 姚振杰[1,2] ZHANG Zhonglin;WANGWei;ZHAO Xisen;WANG Shiyu;HUANG Chunxia;YAO Zhenjie(Shaanxi Yanchang Petroleum(Group)Company,Ltd,Xi’an,Shaanxi 710065,P R of China;Shaanxi Key Laboratory of CO2 Sequestration and Enhanced Oil Recovery,Xi’an,Shaanxi 710065,P R of China)

机构地区：[1]陕西延长石油(集团)有限责任公司,陕西西安710065 [2]陕西省二氧化碳封存与提高采收率重点实验室,陕西西安710065

出　　处：《油田化学》2019年第4期646-650,共5页Oilfield Chemistry

基　　金：国家重点研发计划项目“CO2驱油技术及地质封存安全监测”（项目编号2018YFB0605500）;延长石油集团项目“改善低压低渗油藏CO2驱油效果技术研究”（项目编号ycsy2018ky-A-11）

摘　　要：针对延长化子坪油区开展CO2驱存在驱油机理不明确的问题,采用PVT和细管实验,结合相态模拟,研究了注CO2对化子坪长6储层原油性质及其相态的影响。PVT实验表明,化子坪原油属于典型的欠饱和原油,气油比仅为68 m^3/m^3左右,地层能量相对较弱;但在地层原始温压条件下CO2在化子坪原油中的溶解量可达34.17 mol%,可使饱和油体积膨胀超过15%,黏度下降近50%,且CO2降压析出后对原油具有较强的提抽作用和溶解气驱能力。相态模拟和细管实验结果表明,化子坪原油与CO2的一次接触和多次接触最小混相压力分别为33.31 MPa和14.27 MPa。因此,化子坪油藏CO2驱为非混相驱,其驱油机理以膨胀、降黏、提抽及溶解气驱为主。In order to clear mechanism of CO2 flooding in Huaziping oildom of Yanchang oilfiled,the effects of CO2 on physical properties and phase states of crude oil for Huaziping chang 6 reservoir were studied by PVT and slim-tube test combined with phase simulation.PVT experiment showed that the crude oil was a typical undersaturated crude oil with a gas-oil ratio of only about 68 m3/m3,indicating that the Huaziping chang 6 reservoir is short of stratum energy.However,under the condition of original formation temperature and pressure,the dissolved amount of CO2 in crude oil could reach 34.17 mol%,which could make the volume of saturated oil expand by more than 15%and the viscosity drop by nearly 50%.Moreover,CO2 had a strong extraction effect on crude oil and dissolving gas drive ability during the process of decompressive operation.The results of phase simulation and slim-tube test showed that the minimum miscible pressure of primary contact and multiple contact were 33.31 MPa and 14.27 MPa,respectively.Therefore,CO2 flooding in Huaziping oildom of Yanchang oilfiled belonged to immiscible flooding,and its displacement mechanism was dominated by expansion,viscosity reduction,extraction and dissolution gas flooding.

关 键 词：CO2驱 体积膨胀 降黏 提抽作用 溶解气驱 最小混相压力 

分 类 号：TE357.45[石油与天然气工程—油气田开发工程]