表面活性剂协同低盐度水驱提高致密油藏采收率研究  

Study on Enhancing the Oil Recovery of Tight Oil Reservoirs by Surfactant Combined with Low-Salinity Water Flooding

作　　者：李婷[1] 谢安[1] 倪振[1] 刘永萍[1] Li Ting;Xie An;Ni Zhen;Liu Yongping(PetroChina Xinjiang Oilfield Company,Karamay,Xinjiang 834000,China)

机构地区：[1]中国石油新疆油田分公司,新疆克拉玛依834000

出　　处：《特种油气藏》2023年第1期114-119,共6页Special Oil & Gas Reservoirs

基　　金：中国石油重大科技专项“新疆油田已开发水驱油藏‘二三结合’提高采收率技术研究与应用”(2017E-04-06)。

摘　　要：为探究表面活性剂协同低盐度水驱提高致密油藏采收率机理,以新疆油田某致密砂岩油藏为研究对象,通过自制实验装置,研究了不同注入速度、溶剂配比等条件下,低盐度水驱、表面活性剂驱及二者协同作用对采收率的影响。结果表明:表面活性剂协同低盐度水驱能有效发挥协同优势,提高致密油藏采收率;注入速度过低时表面活性剂能有效改造孔喉界面,但水驱能量不足,注入速度过高时易诱发油水界面锥进,且表面活性剂改造孔喉界面效果有限,导致驱油效率随注入速度的升高先升高后降低;注入速度为0.3 mL/min条件下,低盐度水(NaCl质量分数为0.1%)和十二烷基苯磺酸钠阴离子型表面活性剂(质量分数为0.4%)按7∶3质量配比,驱油效率最高,可达89.79%,相较于单流体驱至少提高了29.83%。现场应用表明:致密油藏单井产量严重衰减后,利用表面活性剂协同低盐度水驱,能有效提高采收率,月产量提升约47%。研究成果可为同类致密油藏高效开发提供借鉴。To explore the mechanism of enhancing the oil recovery of tight oil reservoirs by surfactant combined with low-salinity water flooding,in a study case of a tight sandstone reservoir in Xinjiang Oilfield,the effects of low-salinity water flooding,surfactant flooding and their combination on the recovery efficiency at different injection rates and solvent ratios are studied with self-made test equipment.The result shows:The surfactant combined with low-salinity water flooding can effectively play the synergistic advantages to improve the recovery efficiency of tight oil reservoirs.When the injection rate is too low,the surfactant can effectively modify the pore throat interface,but the energy of water flooding is insufficient.When the injection rate is too high,it is easy to induce the coning of oil-water interface,and the effect of surfactant on modifying the pore throat interface is limited,leading to oil displacement efficiency increasing first and then decreasing with the increase of injection rate.At the injection rate of 0.3 mL/min,the highest oil displacement efficiency of 89.79%is achieved with a 7∶3 mass ratio of low-salinity water(0.1%NaCl mass fraction)to sodium dodecyl-benzene sulfonate anionic surfactant(0.4%mass fraction),which is at least 29.83%higher than that of single-fluid flooding.The field application shows that the surfactant combined with low-salinity water flooding can effectively enhance oil recovery and increase monthly production by about 47%in tight reservoirs where the production is severely depleted per well.The study results can be referred for efficient development of similar tight oil reservoirs.

关 键 词：低盐度水 表面活性剂 致密油藏 提高采收率 协同作用 

分 类 号：TE348[石油与天然气工程—油气田开发工程]