Study On The Optimization Of Injection Parameters In Weak Base ASP Flooding

ASP (alkali/surfactant/polymer) flooding is an enhanced oil recovery technology developed in the 1980s. The results of laboratory experiments and field actual production data show that ASP flooding technology can increase the crude oil recovery by about 20% on the basis of water flooding. Compared with the alkali ASP flooding, weak base ASP flooding can increase oil and reduce water and eliminate the scaling problem of the extraction system. In recent years,weak base ASP flooding technology has been applied in Daqing oilfield.In the process of injection, ASP flooding involves several injection parameters such as slug size, alkali concentration and surfactant concentration. These factors can not only affect the development of oil fields, but also have an effect on the balance between costs and gains.Thus, it is necessary to optimize the injection parameters. In this article, an experimental research on optimization of injection parameters in weak base ASP flooding was carried out in Sazhong block. We learn about the details of geological block, reservoir property and fluid property parameters by investigation. The numerical model is calculated by CMG software.By comparing the different design schemes and oil displacement effects, the pre-polymer slug size, the main slug size, the alkali concentration in main slug, the surfactant concentration in main slug, the vice slug size, the alkali concentration in vice slug, the surfactant concentration in vice slug , rear-polymer slug size and injection rate are optimized Through the study of the resistance coefficient and residual resistance coefficient, the matching relationship between the Alkaline/Surfactant/Polymer flooding system and the reservoir permeability is studied.And the mathematical model of residual resistance coefficient is established. On these bases,the results of numerical simulation are verified by the experiment of indoor physical simulation flooding experiments. The results show that the optimal injection parameters are pre-polymer slug 0.04PV, main slug 0.35PV, alkali concentration in main slug 1.2%,surfactant concentration in main slug 0.3%, vice slug 0.15PV, alkali concentration in vice slug 1.0%, surfactant concentration in vice slug 0.15%, rear-polymer slug 0.2PV, injection speed at 0.15PV/a. In this paper, the weak base ASP flooding injection parameters have an important guiding significance for the development of programs and the the practical application of ASP flooding.