Abstract: In the study of the current model of polymer well testing,the two conditions of multi-layer reservoir and non Newton-Newton composite reservoir were not considered simultaneously,which resulted in the fact that the fitting results of actual data of many offshore polymer flooding reservoirs were not ideal. By taking into account the actual situation of polymer flooding after water flooding in multi-layer offshore reservoirs,a well testing model for polymer flooding after water flooding in triple-layer reservoir was established based on the theory of fluid flow in porous media,type curves were plotted and its influencing factors were discussed by the numerical inversion method and this model was verified by the field examples. The result show that the type curves have six regimes,the typical feature which is different from the triple-layer non composite model is the end-stage upwarp segment,the initial concentration of polymer has little influence on the curve,the crossflow coefficient mainly affects the time of the concave,coefficient ratio and storativity ratio mainly affect the width and depth of the concave,and the composite radius mainly affects the down degree of the upper part of the pressure derivative curve.

Key words: polymer flooding, triple-layered reservoir, well testing, pressure dynamics, non Newton-Newton