渤海X稠油油田聚合物驱优化控制研究

Research on optimal control of polymer flooding in Bohai X heavy oil field

针对渤海复杂河流相X稠油油田油藏条件,考虑到该油田原油黏度变化特征,选用增黏能力较好的HJ聚合物作为驱油聚合物,通过室内填砂管物理模拟驱油实验,研究了原油黏度、聚合物溶液浓度对聚合物驱油效果的影响。结果表明,原油黏度越高,水驱后剩余油越多,后续聚驱的挖潜潜力越大;原油黏度越高,聚驱采收率随聚合物浓度增大而增大的幅度越大,当聚合物浓度达到一定值使水油黏度较高时,也会出现聚驱采收率高粘原油大于低粘原油的现象;从采收率和经济的角度考虑,在复杂河流相油藏条件下,对于黏度为50~500mPa·s的普通稠油,聚驱用聚合物浓度应选用大于等于2000mg/L。

Aiming at the reservoir conditions of the complex river facies X heavy oil field in the Bohai Sea,and considering the characteristics of crude oil viscosity change in this oil field,HJ polymer with better viscosity increasing ability was selected as the oil displacement polymer,and the oil displacement experiment was simulated by indoor sand-filled pipes.The effects of crude oil viscosity and polymer solution concentration on polymer flooding effects were studied.The results showed that the higher the crude oil viscosity,the more oil remaining after water flooding,and the greater the potential of subsequent polymer flooding;the higher the crude oil viscosity,the greater the increase in polymer flooding recovery with increasing polymer concentration.When the polymer concentration reached a certain value and the water-oil viscosity is high,the polymer flooding recovery rate of high-viscosity crude oil is higher than that of low-viscosity crude oil;from the perspective of recovery and economics,the conditions in complex river-phase reservoirs below,for ordinary heavy oil with viscosity of 50~500 mPa·s,the polymer concentration for polymer flooding should be selected to be 2000 mg/L or more.