相渗改善特性减阻剂乳液制备及现场应用

Preparation of friction reducing emulsion with relative permeability modification and its field application

高含水低渗透油藏压裂裂缝效应易导致油井含水率快速上升,常规低摩阻压裂液难以满足控水压裂要求,因此,以丙烯酰胺(AM)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)和N,N-二甲基丙烯酰胺(DMAA)为主要材料,制备了一种具有相渗改善特性的减阻剂乳液(FRA-1),同时表征了合成产物主要基团及乳液粒径分布,考察了FRA-1的减阻性与相渗改善性能,并在胜利油田进行了现场应用。实验结果表明:合成产物在红外谱图中呈现出3种聚合物单体主要官能团的特征峰;乳液粒径约80 nm,随静置时间增加而增大;质量浓度为10 mg/L的FRA-1溶液减阻率可达72.5%,进入储层可降低水相渗透率80%以上,对油相渗透率影响较小。现场应用显示,FRA-1具有良好的减阻效果,压裂后油井含水率降低幅度达50%以上,具有良好的应用前景。

Water-cut of oil wells rises rapidly due to the fracture effect in low permeability reservoirs with high water saturation,and conventional low friction fracturing fluids are difficult to meet the requirements of water control fracturing.With acrylamide(AM),2-acrylamide-2-methyl propane sulfonic acid(AMPS)and N,N-2-methacrylamide(DMAA)as main materials,the friction reducing emulsion(FRA-1)with relative permeability modification was prepared.The main groups and particle size distribution of synthetic product were characterized.The performance of FRA-1 friction reduction and relative permeability modification were investigated,and FRA-1 was also used in Shengli Oilfield.The results show that the characteristic absorption peaks of three polymer monomers in the infrared spectrum confirm the product formation,and the particle size of FRA-1 emulsion is about 80 nm and increases with the standing time.The friction reduction rate of FRA-1 solution by mass concentration of 10 mg/L can reach 72.5%;water phase permeability can be reduced by more than 80%,but oil phase permeability is littlely affected when FRA-1 solution invades the reservoir.In piolt test,FRA-1 possessed good friction reduction effect,and water-cut of oil well decreased by more than 50%,showing good prospect for water control of fractured oil wells.