基于海上X油田新型耐温抗盐驱油剂性能评价及驱油特性研究

Evaluation of the anti-salt performance and study on the characteristics of oil repellent based on offshore X oilfield

随着渤海油田稳产3 000×104t主题的提出,以化学驱为主的三次采油技术在海上油田的高产稳产中占据着较为重要的地位。部分水解的HPAM型聚合物在高温高盐环境下稳定性差、在溶液配注过程中黏度保留率低等因素都影响了聚合物其黏弹性提高驱油效果的实现。本文将两种新型耐温抗盐聚合物(代号为KY-S、KY-K)与海上在用聚合物开展了性能评价及驱油效果分析,结果表明:在模拟X油田高温高盐条件下,新型聚合物KY-S比现场在用SZ1聚合物具有更好的黏度稳定性及耐温性能;经90 d老化后,KY-S黏度保留率为37.8%,而LD2聚合物黏度保留率为29.1%,SZ1聚合物黏度保留率仅为27.4%;扫描电镜检测结果表明新型聚合物分子在水溶液中伸展性好,具备良好抗盐性能。同等条件下室内驱油实验时新型聚合物的驱油效率比现场在用聚合物驱油效率高2.5%。

In order to achieve the grand goal of continuous and stable production of Bohai oil field, the chemical flooding tertiary oil recovery technology has become increasingly prominent in the development of offshore oilfield. The traditional HPAM-type polymer limits the further improvement of polymer flooding recovery due to its poor temperature and salt-tolerant stability and shear resistance. It is necessary to screen a new type of oil displacement system with better performance for offshore injection oilfield. To achieve high yield and stable production of the poly drive oilfield.Based on the condition of Bohai X oilfield reservoir,this paper evaluates the performance of several different molecular weight polymer from the aspects of viscosity, temperature and salt resistance, seepage capacity and oil displacement capacity, which is polymerized with SZ1 polymer. The results showed that the polymer KY-S has better viscosity stability and temperature resistance than SZ1 polymer in situ under the conditions of high temperature and high salt in simulated X oilfield.After aging for 90 d,the viscosity retention rate of KY-S is 37.8 % while that of LD2 polymer is 29.1 %,and that of SZ1 polymer is 27.4 %.The results of scanning electron micrascopy showed that the new polymer molecules had good extersibility and salt resitance in aqueous sdution under the same conditongs,the oil displacement efficiency of the new polymer is 2.5 % hegher than that of the polymer used in the field.