稠油油藏储层冷采用活性分子的性能评价与应用

针对边底水薄层特稠油油藏热采高轮次后注汽易窜,封堵困难,含水大幅上升导致开发效益下降的问题,以丙烯酰胺(AM)、丙烯酸钠(AA)、4-苯基-1-丁烯(PB)、丙烯酰胺-2-甲基丙磺酸(AMPS)为原料、四甲基乙二胺为催化剂制备了水溶性活性分子共聚物(AAPA).研究了油剂比、AAPA加量、pH值、Ca2+、Mg2+、温...

Performance Evaluation and Application of Cold Production Active Polymer Using in Heavy Oil Reservoir

In order to improve the problems of steam channeling and plugging difficulty after high thermal recovery cycles,and the decrease of development profit caused by the sharp increase of produced water in thin-layer extra heavy oil reservoir with edge and bottom water,water-soluble active molecular co-polymer(AAPA)was synthesized using acrylamide(AM),sodium acrylate(AA),4-phenyl-1-butene(PB),acrylamide-2-methylpropanesulfonic acid(AMPS)as reactants and tetramethylethylenediamine as catalyst.The effects of oil to solvent ratio,AAPA dosage,pH value,Ca²⁺,Mg²⁺and temperature on viscosity reduction were studied.The mechanism of viscosity reduction of AAPA was analyzed.The cold field test of chemical viscosity reduction was carried out by multiple concentration and multiple slug injection method.The results showed that the best viscosity reduction effect could be obtained by mixing 1 g/L AAPA with crude oil in a mass ratio of 1∶1.The static viscosity reduction rate of degassed and dehydrated heavy oil with viscosity below 50 Pa·s at 50℃could be more than 90%.AAPA had the characteristics of high salinity tolerance,easy demulsification and wide range of viscosity reduction temperature.The effective viscosity reduction temperature range was 50—180℃.The Ca²⁺resisting concentration was less than or equal to 10 g/L,and the Mg²⁺resisting concentration was less than 3 g/L.When the pH value was less than 4,the heavy oil after viscosity reduction emulsification could be quickly demulsified,and when the pH value was greater than 10,the viscosity reduction activity of AAPA could be further improved.It had been applied on 4 wells,and the effect of fluid extraction and oil increase was obvious.By injecting AAPA into reservoir with multiple concentration and multiple slug,the viscosity of crude oil could be effectively reduced,and the benefit of cold recovery development of thin-layer extra heavy oil reservoir with edge and bottom water could be significantly improved.