The Research On The Mechanism Of Recovery Efficiency Improvement Using Chemical Auxiliary Steam Flooding

Chemical auxiliary steam flooding is the effective measure to improve the recovery factor of heavy oil reservoir. In order to study its mechanism, this article discusses the relationship of the chemical auxiliary steam flooding and enhances oil recovery from four aspects; contain emulsification, interfacial tension and reservoir wettability. This article use static test and one dimensional simulation experimental method combining to analysis the link between the three aspects and the recovery factor. First of all, the ability of emulsification and the rate of improving the recovery is directly proportional to the amplitude, emulsifying ability is stronger, the amplitude of the rate of improving the recovery is larger; secondly, interfacial tension is not the necessary condition to improve oil recovery, when the interfacial tension is greater than10"2mN/m level, with the reduction of the interfacial tension, oil recovery increase gradually. As the interfacial tension drop to10-3mN/m threshold level, oil recovery improve slowly, even have fall; thirdly, the reservoir wettability and recovery efficiency are closely related, the recovery of hydrophilic cores was obviously higher than that of lipophilic, but strong hydrophilic ity is unfavorable to recovery efficiency of ascension, the optimal wettability to neutral wetting;finally, reservoir percolation ability and recovery efficiency are highly correlated, the seepage ability stronger, recovery efficiency increases.Analytical chemistry auxiliary steam drive mechanism through these experiments:(1) The emulsifying ability is stronger; the crude oil viscosity is lower. The emulsification can improve the mobility ratio, easy to form stable crude oil emulsion and easy to peel and oil migration;(2) With the reduction of the interfacial tension,crude oil reduced adhesion work also. It Can facilitate stripping of crude oil, and improve sweep efficiency, thus improve the recovery efficiency;(3) Nature wettability can increase sweep efficiency of water, and improve recovery;(4) With the increase of core flow ability, the core will form the big hole, big hole can contribute to the stripping and migration of crude oil, so as to improve oil recovery. This article analyzes the chemical auxiliary steam flooding mechanism from four aspects, provides guidance for the application of chemical auxiliary steam flooding in oilfield.