摘要
胜坨油田地层温度大于80℃、地层水矿化度大于20000 mg/L、地层水钙镁离子大于500 mg/L,非均质性强。根据该油藏特点,室内研制了强化聚合物驱油体系,在超高分疏水缔合型聚丙烯酰胺中加入聚合物强化剂。结果表明,强化剂加量由0增至2500 mg/L,驱油体系的表观黏度由7.8增至42.9 mPa·s,黏性模量由120增至315 mPa,弹性模量由0增至106 mPa。在模拟胜坨油田条件下,强化聚合物驱油体系(超高分缔合聚合物、强化剂质量比4:1)老化60 d的黏度保留率为85.5%,好于改性聚丙烯酰胺(GXPAM)(66.2%),热稳定性良好。在非均质岩心中注入强化聚合物驱油体系(2500 mg/L),高渗模型产液百分比由98.5%逐渐降低,最低值为32.7%;低渗模型产液百分比由1.5%逐渐增大,最大值为67.3%;后续水驱1.0 PV时,高渗模型产液百分比为58.5%,低渗模型的为41.5%,岩心非均质性得到明显改善。岩心渗透率级差分别为1:5和1:3时,强化聚合物驱油体系的采收率增幅为26.0%和10.9%,GXPAM的为14.8%和7.1%。强化聚合物驱油体系的驱油效果明显优于GXPAM,并且在高渗透率级差下的驱油效果较好。
In Shengtuo oilfield,the formation temperature was more than 80℃,the salinity of formation water was above 20000mg/L,the concentration of calcium and magnesium ions was more than 500 mg/L,and the heterogeneity of reservoir was strong.According to the reservoir characteristics of Shengtuo oilfield,reinforced polymer flooding oil system was developed by adding polymer enhancer to ultra-high molecular weight hydrophobic associating polyacrylamide. The results showed that when the dosage of enhancer increased from 0 to 2500 mg/L,the apparent viscosity of oil displacement system increased from 7.8 to 42.9 mPa·s,the viscous modulus increased from 120 to 315 mPa,and the modulus of elasticity increased from 0 to 106 mPa. In the simulation of Shengtuo oilfield conditions,when the mass ratio of ultra-high molecular weight associative polymer and enhancer was equal to four,the viscosity retention rate of reinforced polymer flooding system was 85.5% after 60 days,which was better than that of modified polyacrylamide(GXPAM)(66.2%). The reinforced polymer displacement system had well thermal stability. When the reinforced polymer flooding oil system(2500 mg/L)was injected in heterogeneous core,the liquid production percentage of hypertonic model decreased from 98.5% gradually with 32.7% minimum value,and that of low permeable model increased from1.5% step by step with 67.3% maximum value. When the sequent water(1 PV)was injected,the liquid production percentage of hypertonic model was 58.5%,and that of low permeable model was 41.5%. The core heterogeneity was improved obviously. When the core permeability ratio was 1:5 and 1:3,the enhanced recovery rate of reinforced polymer flooding oil system increased by26.0% and 10.9%,however that of GXPAM increased by 14.8% and 7.1%,respectively. Oil recovery efficiency of reinforced polymer flooding oil system was better than that of GXPAM,and the flooding effect was better in high permeability ratio.
出处
《油田化学》
CAS
CSCD
北大核心
2014年第2期278-281,共4页
Oilfield Chemistry
基金
国家重大专项"高温高盐油田化学驱提高采收率技术"(项目编号2011ZX05011-004)
关键词
强化聚合物
聚丙烯酰胺
强化剂
高温高盐
驱油效果
胜坨油田
reinforced polymer
polyacrylamide
enhancer
high temperature and high salinity
oil displacement effect
Shengtuo oilfield
