采用岩心驱替实验模拟油藏中原油乳化过程,通过可视岩心驱替实验研究乳状液形成机理,分析不同运移距离、乳化剂浓度和注入速度下形成乳状液的粒径分布及孔喉级别乳状液形成条件,通过测量形成的乳状液黏度、储能模量和耗能模量,研究乳状液的黏弹性。研究表明:多孔介质中乳状液形成机理主要为残余油卡断作用和乳化剂溶液的剪切作用。当运移距离大于1/3倍注采井距、乳化剂浓度为0.4%~0.5%、注入速度为0.3~0.4 m L/min时,能够形成稳定性较好的孔喉级别乳状液。当乳化剂浓度为0.4%和0.5%、剪切速度为7.34 s-1时,乳状液黏度可达48.6~70.3 m Pa·s。随着乳化剂浓度的增加,乳状液的储能模量和耗能模量增大,乳状液黏弹性增强。
Resin and asphaltene were separated from Daqing crude oil and were dissolved in decane The interfacial viscoelasticity was investigated by applying the controlled stress model of oscillatory ring interfacial rheometer CIR 100 The effects of resin, asphaltene contents in decane, pH values, and demulsifiers in aqueous phase on interfacial viscoelasticity were studied It was shown the interfacial viscoelasticity of water/decane containing asphaltenes or resins is of the order of 4 higher than that of water/decane, and the interfacial viscoelasticity increased with increasing resin and asphaltene concentrations in decane When the pH value in aqueous phase was about 7,interfacial elasticity approached a maximum Demulsifers in aqueous phase could obviously reduce interfacial viscoelasticity and interfacial
