高凝油油藏注水开发方式研究

通过室内实验分析了高凝油油藏储层敏感性、流体性质和不同温度下的水驱油规律。结果表明：温度和储层敏感性对高凝油油藏的开发影响较大;高凝油由于其含蜡量高、凝固点高,温度变化对其流变特性影响很大;随着温度的下降,油相渗透率降低,降温后再升温,油相渗透率可以恢复,但不可逆;温度对高凝油油藏驱油效率影响较大,温度低于析蜡温度以后,蜡的析出影响水驱油效率;而当析蜡温度接近地层温度时,就会产生冷伤害,因此应采取相应措施使油层温度保持在原油析蜡温度以上。沈84-安12块注水井温度测试表明,目前地层存在冷伤害,如果油层温度下降过快,应适当考虑提高注入水温度,使油层温度高于析蜡温度,改善油田开发效果。

WATEFLOODING STRATEGY FOR HIGH POUR-POINT OIL RESERVOIR

This paper analyzes the sensitivity of high pour-point oil reservoir,fluid property and the law of water flooding with different temperature.The results show that temperature and reservoir sensitivity affect water flooding result of high pour-point oil reservoir.Because of the high wax content and the high solidifying point of oil in high pour point oil reservoir,the influence of temperature change on its rheological characteristics is large.The experimental result shows that the oleic permeability reduces along with the temperature dropping,and then temperature increases after the temperature decreasing,the permeability is recoverable,but irreversible.Temperature of high pour-point oil reservoir has a greater impact on the efficiency of water flooding.When temperature is lower than wax precipitation temperature,the wax precipitation affects the efficiency of water flooding.If the wax precipitation temperature is close to formation temperature,it will cause cold injury.So the measure should be put in practice to make the formation temperature higher than the wax precipitation temperature.Water injection well temperature test of Shen 84-An 12 block shows that strata exists cold injury at present.If the reservoir temperature drops too fast,consideration should be taken to improve the injected water temperature,make the formation temperature higher than the wax precipitation temperature and improve oil field development results.