Evaluation Of Remaining Oil Potentialities And The Study Of Optimizing The Redeveloping Measures For Thick Layers' High Water Cut Stage In Sabei Developing Area

The East Block of Beierxi of Sabei developing area is located in the Saertu pure oil field of changyuan, Daqing , which belongs to large rivers'depositional system of Laxi. At present, the East Block of Beierxi has run into the high water cut stage with 96.3% of the composite water cut, 58.8% of the reserve recovery, which is charactered with highly watered out degree of all blocks, obvious interlaminar contradiction, and scattered distribution of remaining oil. Hereby, there are big challedges to redevelop the remaining oil. This paper has established the fine geological modeling, and preceded the accurate geologic description towards every sedimentation unit combined with the thick layers'dynamic and static data of the East Block of Beierxi in Sabei. Among them, the reserve proportion of PI2 and PI5+6 is very big, accompanying with the widely distribution of channel sand and high drilling encounter rate. It has made the prediction by the method of numerical simulation aiming at the distribution law of the remaining oil on the basis of geological modeling. The remaining oil mainly assists in the low-permeability, thin and poor layer, river edge or the interstream sand. The watered out degree of all sedimentation unit is very serious, the oil saturation is rather low, and the interlaminar contradiction is very obvious, so it's troublesome to redevelop the oil remaining. It also has quantitatively evaluated the remaining oil potentialities in high water cut stage by multiple fuzzy comprehensive evaluations considering the characteristics of reservoir heterogeneity and the influential factors of producing data. And it has established the quantizing model for the analysis of remaining oil potentialities, completed the quantitative description towards the result of the qualitative analysis. Moreover, it has classified the PI group into there potential area and provided the reference for remaining oil potentialities in high water cut stage according to the qualitatively comparative analysis of six sedimentation units prior to Polymer Flooding and now.It has manufactered six projects after Polymer Flooding which are separate zone water injection, profile modification, water plugging, subdivision water injection together with profile modification,and subdivision water injection with profile modification and water plugging according to the characteristics of all the sediment units ,based on the conclusion of the remaining oil distribution law and type of high layers in high water cut stage in the East Block of Beierxi of Sabei. And it has also made the numerical simulation forecast towards the production performance index. The forecast results show that all the mentioned projects can control the ascending velocity of the water cut differently, relieve the interlaminar contradiction and improve the recovery of thick layers. The best project is subdivision water injection with profile modification and water plugging, which can decrease the water cut by 5.17% and improve the recovery by 3.32%. Next is the project subdivision water injection with profile modification, which can decrease the water cut by 4.83% and improve the recovery by 2.72%. The result indicates that we can limit the ascending velocity of the water cut effectively, relieve the interlaminar contradiction and improve the reserve recovery further by virtue of implementing various technologies for redeveloping remaining oil simultaneously.