聚合物增黏CO2性能研究

Study on viscosity increasing properties of CO2 by polymer

针对CO2驱过程中普遍存在的CO2气窜问题,通过云点压力测量筛选出2种在CO2中具有较好溶解性的聚合物,室内实验评价了2种聚合物增黏CO2的性能,以增黏倍数为指标评价了温度、压力对聚乙烯基乙醚、聚-1-癸烯增黏CO2的效果。结果表明:聚乙烯基乙醚和聚-1-癸烯在CO2中都具有很好的溶解性,能够显著提高CO2的黏度;聚-1-癸烯的增黏效果好于聚乙烯基乙醚,聚合物用量越大,增黏效果越好,温度或压力升高,增黏倍数下降;聚-1-癸烯可以显著降低CO2的流度,且注入流速越大,流度降低幅度越大。因此,矿场应用时,要控制增黏体系的温度和压力,适当提高注入速度,防止气窜。

Considering the common problem of gas channeling in CO2 flooding,two polymers with good solubility in CO2 were screened out through cloud point pressure measurement.The viscosity increasing performance of the two polymers was evaluated in laboratory experiments.The viscosity increasing ratio was used as the index to evaluate the effect of temperature and pressure on thickening CO2 by poly(ethyl vinyl ether)and poly(1-decene).The results show that both poly(ethyl vinyl ether)and poly(1-decene)have good solubility in CO2 and could significantly improve the viscosity of CO2;the thickening effect of poly(1-decene)is better than that of poly(ethyl vinyl ether).The higher the polymer dosage is,the better the thickening effect is,and with the increase of temperature or pressure,the viscosity increasing ratio of CO2 decreases.The fluidity of CO2 can be significantly reduced by poly(1-decene),and the greater the injection velocity is,the greater the fluidity reduction is.It is suggested that the temperature and pressure of thickening system should be controlled and the injection speed should be increased to prevent gas channeling.