高温高盐高压油藏条件下泡沫适应性研究

Study on adaptability of foam flooding system in fractured vuggy reservoirs under high temperature, high pressure and high salt conditions

关键词:  泡沫  泡沫综合指数  黏度  形貌  高温 

Key words:  foam  foam comprehensive index  viscosity  morphology  high temperature

摘要:

目的 针对现有研究未有模拟高温(≥120 ℃)高压(≥40 MPa)泡沫驱油条件、泡沫性能难以反映现场真实情况的问题,在恒定泡沫液质量分数为1%、压力为40 MPa、矿化度为22×10⁴ mg/L的缝洞油藏条件下,开展了5种泡沫体系性能评价。方法 采用高温高压流变仪测试了不同高温条件下的泡沫基液黏度、起泡体积、消泡半衰期和泡沫综合指数,体视显微镜原位观察高温泡沫形貌。结果 温度适应性从强到弱的泡沫顺序为:双重交联聚合物复合泡沫＞微分散凝胶强化泡沫＞纳米黑卡增强泡沫＞常规高温泡沫＞高温淀粉凝胶泡沫。结论 除微分散凝胶强化泡沫外,其余4种泡沫在温度由110 ℃升至150 ℃过程中,泡沫平均直径均呈明显增大的趋势,双重交联聚合物复合泡沫和微分散凝胶强化泡沫耐高温性能相对更好；除双重交联聚合物复合泡沫外,其余4种泡沫的黏度、起泡体积、半衰期、泡沫综合指数均随着温度的升高而降低,而双重交联聚合物复合泡沫液的起泡体积随着温度的升高而升高。 

Abstract:

Objective In view of the fact that the existing research had not simulated the high temperature (≥120 ℃) and high pressure (≥40 MPa) conditions of the foam flooding, and the foam performance was difficult to reflect the real situation on site, the adaptive performance evaluation of five foam systems was carried out at the conditions of fractured vuggy reservoir with constant foam concentration of 1 wt%, pressure of 40 MPa and salinity of 22×10⁴ mg/L. Methods The viscosity of foam base solution under different high temperature conditions was studied by high temperature and high pressure rheometer. The foaming volume, defoaming half-life and foam composite index under different high temperature conditions were studied by high temperature and high pressure foaming instrument. The morphology of high temperature foam was observed in situ by stereomicroscope. Result The results showed that the order of foam with strong to weak temperature adaptability was determined as follows:double cross-linked polymer composite foam > differential dispersion gel reinforced foam > nanoblack card reinforced foam > conventional high-temperature foam > high temperature starch gel foam. Conclusion s Except for differential dispersion gel reinforced foam, the average diameter of foam of the other four foams showed significant increase trend when the temperature increased from 110 ℃ to 150 ℃. The double cross-linked polymer composite foam and differential dispersion gel reinforced foam had better high-temperature resistance. Except for double cross-linked polymer composite foam, for the other four foams, the viscosity, foaming volume, half-life and foam comprehensive index all decreased with the increase of temperature. While the foaming volume of the double cross-linked polymer composite foam increased with the increase of temperature.