北布扎奇油田聚合物弱凝胶体系的研究

Study on the polymer weak gel system in north buzachi oilfield

研究了适合北布扎奇油田地层水油藏条件下的聚合物与酚醛树脂交联的弱凝胶体系.利用黏度法筛选出了弱凝胶调驱体系的配方,其中聚合物主剂SD6800的质量浓度为1 500mg/L,酚醛树脂交联剂TD-2A和TD-2B的质量浓度分别为300和200mg/L;SEM图片证实了其凝胶网络结构的存在.同时利用MCR 301流变仪测定了最佳凝胶体系的动态黏弹性,发现交联反应7d时体系的黏弹性达到最大,且G′<0.1Pa.温度越高,凝胶体系的黏度越低,90℃时,最低黏度保持在500mPa.s以上.确定了高矿化度油田产出水配制较高黏度的弱凝胶体系是可行的.

In view of the characteristics of strong heterogeneity for the reservoir and high salinity in formation in North Buzachi Oilfield,a weak gel system cross-linked by polymer and phenolic resin which could be adapted for the conditions of reservoir has been studied.Viscosity method was used to determine the optimal formula of the weak gel system and given as follows：the main agent of polymer SD6800 with a concentration of 1 500 mg/L;the cross-linking agent of phenolic resin,TD-2A and TD-2B with the concentrations of 300 and 200 mg/L,respectively.SEM images confirmed the existence of networks in the weak gel.Furthermore,MCR 301 rheometer was used to test dynamic viscoelastic properties of the weak gel and the results showed that the viscoelastic value reached a maximum after 7 d for cross-linking reaction,and G′0.1 Pa.Furthermore,the weak gel viscosity decreased with increasing of temperature,however the lowest viscosity could still reach 500 mPa·s even at 90℃.The feasibility of preparing high viscosity weak gel by using oilfield produced water has also been proved.