The Research On The Practicability Of Slug Of Gel Flooding & Surfactant Flooding After Polymer Flooding

With the continuously exploitation of oil in reservoir, the majority of the initial development of oil fields have entered into the estate of high water cut exploitation. Daqing Oilfield comprehensively develops the technology of polymer flooding at some of the major reservoir, statistics results show that polymer flooding's oil recovery enhances more than 10% on the basis of water flooding. However, there is still a great quantity of crude petroleum exists in the layer after polymer flooding, therefore, after polymer flooding how to improve the residual oil's recovery ratio is particularly important.In this paper, the experimentation simulates reservoir conditions of experimental area P1-4 in second pilot area of Oil Production Plant of Daqing Oilfield, and uses of the working site injected water, the medium or high molecular weight polymer in Daqing, cross linking agent and surface acting agent , by measuring the gel system's gelation characters and surfactant's interfacial tension to study compatibility of gel system and surfactant, selecteing with chromium ion gel system which compatible with injecting water ,molecular weight is 2,5million, the polymer concentration is 1800mg/L ,the crosslinking ratio is 10:l;Surfactant system recreates RMA-1 surfactant system for Daqing which concentration is 0.3%.Through the distinction experiments of injecting gel sliver surfactant to core long core, optimized gel - surfactant's slug size which alternately injected, and optimized the number of alternative injection. Through the artificial system of large flat-panel model's study alternating injection's influx peculiarity and displacement characteristics of gel system and a surfactant (poly and surfactant multisystem) , experiments show that after polymer flooding the gel and surfactant big slug alternately flooding's recovery ratio enhances more than 7.39% on the basis of polymer flooding ,and on the basis of polymer flooding, after polymer flooding the gel and surfactant small slug alternately flooding's recovery ratio enhances more than 8.20% on the basis of polymer flooding ,and on the basis of polymer flooding, after polymer flooding gel and poly and surfactant multisystem's recovery ratio enhances 11.05%.In this paper, it provide the technical foundation for the further research of gel and a surfactant flooding after polymer flooding (poly and surfactant multisystem ) and well site's subsequence testing program designing.