针对新疆油田七中区开发现状,设计聚合物-表面活性剂二元驱的填砂管、天然岩心及微观模型驱油实验,研究二元驱提高采收率机理,为油田现场提供二元驱优化配方。二元驱采收率增幅随着水油黏度比增大而增大,随着界面张力减小而增大。毛细管准数反映二元体系溶液黏度和界面张力的协同效应,应以其为准优化筛选最佳配方。新疆油田七中区二元驱溶液临界黏度比2.5、临界界面张力数量级为1×10-2 mN/m、临界毛细管准数数量级为1×10-3;优选出配方为0.3% KPS-1+1 115 mg/L HPAM,可提高采收率23.96%。二元驱通过聚合物增黏,降低驱替相流度,增加油相流度,使流度比减小,克服了注水指进,增加了吸水厚度,从而提高波及系数,进而启动盲端残余油;通过表面活性剂降低界面张力,降低黏附功,使残余油乳化、剥离、拉丝并易于启动,同时乳状液进一步增加驱替相黏度,在低界面张力和较高黏度下,毛细管准数大幅度提高,从而提高洗油效率,进而启动岛状、柱状及膜状残余油,最终提高了采收率。图13表3参16
刘卫东, 罗莉涛, 廖广志, 左罗, 魏云云, 姜伟
. 聚合物-表面活性剂二元驱提高采收率机理实验[J]. 石油勘探与开发, 2017
, 44(4)
: 600
-607
.
DOI: 10.11698/PED.2017.04.13
Aiming at the development situation of the Xinjiang oil field, the mechanism of enhancing oil recovery by the Polymer-Surfactant Binary Flooding (SP Flooding) was studied through SP Flooding sand pack, natural core and micro model experiments, and Optimum SP Flooding formula is provided. The results show that the enhanced oil recovery by the SP Flooding increases with the increase of the viscosity ratio between water and oil or the decrease of the interfacial tension. Capillary displacement ratio can reflect the synergetic effect of viscosity and interfacial tension and help screen out the optimum formula of the SP Flooding. For Qizhong block in Xinjiang Oilfield, where the critical viscosity ratio of SP flooding solution is 2.5, the order of magnitude of the critical interfacial tension is 1×10-2 mN/m, and the order of magnitude of the critical capillary displacement ratio is 1×10-3, the optimum formula of the SP Flooding composed of 0.3% KPS-1+1 115 mg/L HPAM can enhance the oil recovery by 23.96%. The polymer in the SP Flooding system increases the viscosity of the displacement fluid, accordingly the fluidity of the aqueous phase reduces and that of the oil phase increases, and the resulting decrease of the mobility ratio can control waterflood fingering, make water absorption thickness increase, enhance sweep efficiency and thus activate the residual oil trapped in dead ends. The surfactant decreases interfacial tension, and the resulting decrease of adhesion work makes residual oil emulsified, stripped, wiredrawn and easy to move. In addition, the emulsion liquid further increases the viscosity of the aqueous phase, and with interaction of lower interfacial tension and high viscosity of the emulsion liquid, the capillary displacement ratio is greatly enhanced, which in turn improves the oil displacement efficiency by displacing isolated-island, columnar and membranous residual oil, and consequently a higher oil recovery.
[1] WANG Yefei, ZHAO Fulin, BAI Baojun, et al. Optimized surfactant IFT and polymer viscosity for surfactant-polymer flooding in heterogeneous formations[R]. SPE 127391, 2010.
[2] YANG Jingyi, LI Zhenquan, XU Buhua, et al. Stability and separation of heavy crude SP flooding produced water[J]. Environmental Science & Technology, 2013, 36(10): 7-12.
[3] CHEN T, ZHANG G, GE J. Dynamic interfacial tension between Gudao heavy oil and petroleum sulfonate/HPAM complex systems[J]. Petroleum Science & Technology, 2012, 30(4): 1417-1423.
[4] PUERTO M, HIRASAKI G J, MILLER C A, et al. Surfactant systems for EOR in high-temperature, high-salinity environments[J]. SPE Journal, 2012, 17(1): 11-19
[5] ROGACHEV M, KONDRASHEV A. 新型疏水型聚合物体系液流转向性能实验评价[J]. 石油勘探与开发, 2015, 42(4): 507-511.
ROGACHEV M, KONDRASHEV A. Experiments of fluid diversion ability of a new waterproofing polymer solution[J]. Petroleum Exploration and Development, 2015, 42(4): 507-511.
[6] 罗莉涛, 廖广志, 刘卫东, 等. Marangoni对流启动残余油微观机理[J]. 石油学报, 2015, 36(9): 1127-1134.
LUO Litao, LIAO Guangzhi, LIU Weidong, et al. Micromechanism of residual oil mobilization by Marangoni convection[J]. Acta Petrolei Sinica, 2015, 36(9): 1127-1134.
[7] 王渝明, 王加滢, 康红庆, 等. 聚合物驱阶段提高采收率预测模型的建立与应用[J]. 石油学报, 2013, 34(3): 513-517.
WANG Yuming, WANG Jiaying, KANG Hongqing, et al. Establishment and application of a prediction model for enhanced oil recovery in polymer flooding[J]. Acta Petrolei Sinica, 2013, 34(3): 513-517.
[8] 程杰成, 吴军政, 胡俊卿. 三元复合驱提高原油采收率关键理论与技术[J]. 石油学报, 2014, 35(2): 310-319.
CHENG Jiecheng, WU Junzheng, HU Junqing. Key theories and technologies for enhanced oil recovery of alkaline/surfactant/ polymer flooding[J]. Acta Petrolei Sinica, 2014, 35(2): 310-319.
[9] DAI Caili, WANG Kai, LIU Yifei, et al. Reutilization of fracturing flowback fluids in surfactant flooding for enhanced oil recovery[J]. Energy & Fuels, 2015, 29(4): 2304-2311.
[10] SHIRAN B S, SKAUGE A. Enhanced oil recovery (EOR) by combined low salinity water/polymer injection[J]. Energy & Fuels, 2013, 27(3): 1223.
[11] SHAH D O, SCHECHTER R S. Improved oil recovery by surfactant and polymer flooding[M]. New York: Academic Press, 1977.
[12] RAI K, JOHNS R T, LAKE L W, et al. Oil-recovery predictions for surfactant polymer flooding[R]. SPE 124001, 2009.
[13] BUIJSE M A, PRELICZ R M, BARNES J R, et al. Application of internal olefin sulfonates and other surfactants to EOR. Part 2: The design and execution of an ASP field test[J]. SPE Improved Oil Recovery Symposium, 2010, 115(B9): 5424-5425.
[14] 白宝君, 周佳, 印鸣飞. 聚丙烯酰胺类聚合物凝胶改善水驱波及技术现状及展望[J]. 石油勘探与开发, 2015, 42(4): 481-487.
BAI Baojun, ZHOU Jia, YIN Mingfei. A comprehensive review of polyacrylamide polymer gels for conformance control[J]. Petroleum Exploration and Development, 2015, 42(4): 481-487.
[15] 狄勤丰, 张景楠, 华帅, 等. 聚合物-弱凝胶调驱核磁共振可视化实验[J]. 石油勘探与开发, 2017, 44(2): 270-274.
DI Qinfeng, ZHANG Jingnan, HUA Shuai, et al. Visualization experiments on polymer-weak gel profile control and displacement by NMR technique[J]. Petroleum Exploration and Development, 2017, 44(2): 270-274.
[16] 刘卫东. 聚合物/表活剂二元驱提高采收率技术研究[D]. 北京: 中国科学院研究生院, 2010.
LIU Weidong. Studies on enhancing oil recovery technology of polymer/surfactant binary flooding[D]. Beijing: Graduate University of Chinese Academy of Sciences, 2010.
