Effect Of Particles On The Stability Of The Crude Oil Emulsions

With the development of EOR technique, lots of chemicals were added in crude oil exploitation, resulting in great affection on the dehydration system. Solids existed in crude oil is one of the important influencing factors. Based on this situation, my study on how the particles effect on the crude oil emulsion stability is significant. Crude oil from Xinjiang oilfield was taken as research object and the solids inside were studied via energy spectrum analysis. It indicated that there were seven kinds of particles inside the crude oil. According with different sources, particles were classified into three types:formation solids, microbial metabolites and the crude oil exploitation process bringed in particles. All of them were studied independently on the stability of crude oil emulsions.Quartz, kaolin, diatomite and bentonite were involved to study how the formation solids worked on crude oil emulsion. It showed that bentonite stabilized crude oil emlusion was most stable, SiO2 and kaolin next and diatomite last. Zeta potential,θ, interfacial film strength and its thickness, droplet and particle diameter, sedimentation velocity measures were investigated to study the solids stabilization mechanism. Cluster analysis and Pearson dependence relevance were adopted to analyze the connections between those measure methods metioned above. It turned out to be that those methods could be clustered into two classes. With the contact angles based on water phase smaller, Zeta potential, droplet and particle diameter greater, the solids stabilized emulsions behaved more unstable. Asphaltene existed in crude oil also had great effects on the emulsion stability. Also we reached to a conclusion that crude oil exploitation process bringed in particles like waste water reusing one affected the dehydration significantly. Whill scaling solids, drilling mud and additives only affected in high-concerntration. The impact effect of microbial metabolites was next to waste water resuing particles.Infrared spectrum was used to analyse oil properties and it turned out to be oxygen content increased. The changed oil properties conbined with particles contribution increased the stability. Effective measures were put forward to solve the dehydration difficulty problem. 11# and 12# silicone demulsifiers improved dewatering efficiency to 79% when the crude oil emulsion was mixed with 30% ageing oil. As to recovery oil, ultrasonication process was treated on emulsion mixed with 30% recovery oil and the dewatering efficiency reached 99%.