二氧化碳对原油中胶质沥青质作用的可视化研究  

Visualization of Effects of CO_2 on Colloid and Asphaltene in Crude Oil

作　　者：刘晓蕾[1,2,3] 杨思玉[2,3,4] 秦积舜[2,3,4] 李实[2,3,4] 姚小琪 Liu Xiaolei Yang Siyu Qin Jishun Li Shi Yao Xiaoqi(Institute of Fluid Mechanics, Chinese Academy of Sciences, LangC＇ang, Hebei 106500, China PetroChina Research Institute of Petroleum Exploration ＆ Development, Beijing 100083, China State Kay Laboratory of Enhanced Oil Recovery, Beijing 100083, China National Energy CO2 Flooding and Sequestration Technology R ＆ D （Experiment） Center, Beijing 100083, China PetroChina Changqing Oilfield Company, Jingbian , Shaanxi 718500, China)

机构地区：[1]中国科学院渗流流体力学研究所,河北廊坊106500 [2]中国石油勘探开发研究院,北京100083 [3]提高石油采收率国家重点实验室,北京100083 [4]国家能源二氧化碳驱油与埋存技术研发(实验)中心,北京100083 [5]中国石油长庆油田分公司,陕西靖边718500

出　　处：《特种油气藏》2017年第2期149-154,共6页Special Oil & Gas Reservoirs

基　　金：国家重点基础研究发展计划"973"项目"孔隙介质中相态实验与理论研究"(2011CB707304);国家油气重大专项"CO_2驱油与埋存油藏工程技术及应用"(2016ZX05016-001);中国石油天然气股份有限公司专项"长庆油田低渗透油藏CO_2驱油与埋存关键技术研究应用"(2014E3606)

摘　　要：为明确CO_2驱油过程中胶质沥青质沉淀原因,从原油中分离出胶质和沥青质分别与正庚烷和甲苯配置成胶质模拟液和沥青质模拟液,并用2种模拟液分别与CO_2组成不同摩尔分数的二元体系,通过高压显微固相沉淀实验,观察2个体系中固相颗粒的变化规律,探究CO_2对胶质沥青质的作用机理。实验表明:胶质模拟液-CO_2体系中CO_2的摩尔分数达到12.50%时,胶质颗粒发生沉淀,随CO_2含量增加沉淀半径增大;当CO_2摩尔分数增至35.00%时,胶质沉淀开始沉积,发生聚集;当CO_2的摩尔分数大于50.00%时,降低体系压力至泡点压力以下,CO_2先从正庚烷液相中析出,后从液状胶质聚集体中析出。沥青质模拟液-CO_2体系在泡点压力处颗粒半径最大;随CO_2含量增加,沥青质颗粒沉淀半径增大;当CO_2摩尔分数增至60.00%时,沥青质颗粒发生聚集形成沉积。该项研究对于分析CO_2驱过程中胶质沥青质对沉淀的贡献情况、沉淀生成的主要原因以及如何减小沉淀对生产造成的伤害具有重要指导作用,对于增强原油的运移能力进而提高储层原油采收率具有理论指导意义。This paper focuses on the reasons for the deposit of colloid and asphaltene in the process of CO2 flooding. First, colloid simulation fluid was prepared with n-beplane, mehtylbenzene and the colloid separated from the crude oil, and asphahene simulation fluid was prepared with n-heptane, mehtylbenzene and the asphaltene separa- ted from the crude oil. Second, two simulation fluids, combined with CO2 respectively constituted binary systems with different mole fractions. Third, high-pressure microscopic solid deposit experiments were conducted to observe the change laws of solid particles in two systems and explore the effect mechanisms of CO2 on colloid and asphalt- ene. It is indicated that colloid particles begin to deposit when the mole fraction of CO2 in colloid simulation fluid- CO2 system reaches 12. 50%. With the increasing of CO2 content, the deposit radius of colloid particles increases. When CO2 mole fraction rises to 35.00%, the colloid deposit begins to settle and accumulate. When CO2 mole frac- tion is higher than 50. 00%, CO2 will precipitate first from n-heptane fluid phase and then from colloid liquid ag- gregates if the pressure of the system drops below the saturation pressure. In asphaltene simulation fluid-CO2 sys- tem, the radius of particles is the largest at saturation pressure. With the increasing of CO2 content, the deposit ra-dius of asphahene particle increases. When CO2 mole fraction rises to 60.00%, the asphahene particles begin to accumulate and settle. This research plays an instructive role in analyzing the contribution of colloid and asphaltene to deposits in the process of C02 flooding, the main reasons for the deposit and the way to reduce the damage of de- posit to production. And it is theoretically significant to strengthening the migration capacity of crude oil and conse- quently improving the oil recovery factor of reservoirs.

关 键 词：胶质 沥青质 二氧化碳 高压显微固相沉淀实验 可视化 提高采收率 

分 类 号：TE135[石油与天然气工程—油气勘探]