中国南海东部稠油油藏双功能驱油剂评价与应用

EXPERIMENTTAL STUDY AND FIELD TEST OF DUAL-FUNCTION FLOODING AGENT FOR HEAVY Oil RESERVOIRS IN THE EASTERN OF SOUTH CHINA SEA

针对中国南海东部稠油油藏注入压力高、地层能量补充不足、油水流度比大、水驱效率低的问题,在中国南海东部X油田应用了由甜菜碱型表面活性剂和十六烷基类增强剂配制的双功能驱油剂。结果表明:该驱油剂够使亲油疏水界面转变为亲水疏油界面,与目标油藏稠油界面张力低至1.35×10^(-4)mN/m,与空白水驱相比,岩心物模试验注入压力降低16.74%~28.42%,采收率提高15.5%以上。中国南海东部X油田A井组矿场试验表明:与措施实施前相比,水井注入压力由6.79 MPa下降至1 MPa,视吸水指数由73.78 m^(3)/(d·MPa)提高至703.22 m^(3)/(d·MPa),井组日增油114 m^(3)/d,阶段增油11243 m^(3)/d。

There are problems such as high injection pressure,insufficient energy replenishment,high mobility ratio of oil and water,and low water flooding efficiency in the eastern South China Sea.A dual-function oil flooding agent was experimental studied for the X oilfield in the eastern South China Sea.It is a dual functional oil displacement agent consisting of betaine type amphoteric surfactant and hexadecane enhancer.The results indicate that the oil displacement agents can transform hydrophilic interfaces into lipophilic interfaces,and the interfacial tension of the target reservoir’s heavy oil is as low as 1.35×10^(-4)mN/m.Compared with water flooding,the injection pressure of the core physical model test decreased by 16.74%28.42%,and the recovery rate increased by more than 15.5%.Field tests in the A well group of the X oilfield in the eastern part of the South China Sea showed that the injection pressure of the water well decreased from 6.79 MPa to 1 MPa,and the apparent water absorption increased from 73.78 m^(3)/d to 703.22 m^(3)/d.The daily oil increase of the well group is 114 m^(3)/d,and the stage oil increase is 11243 m^(3)/d.