The Field Test Research On Polymer Flooding For The Third Class Oil Layers In Daqing Oilfield

The industrialized application and popularize of polymer flooding in the Daqing oilfield have been lasting for 14 years. The technology of polymer flooding developed quickly and the systematical matching technology of reservoir engineering has been built. The polymer flooding object has been turned from the main oil layers to the Second Class oil layers. For exploring and studying the improved recovery methods of the Third Class oil layers, the field test research on polymer flooding of the Third Class oil layers for Putaohua,Saertu and Gaotaizi layers in the south,middle and north of Saertu development areas has been developing. According to the research results, the low molecular weigh polymer can be continuously injected into the Third Class layers under the specified well spacing. The effects of oil increased and water cut decreased which synthesis water cut drops 5 to 7 percent have been achieved. The useless reservoir isn't employed effectively and the producing thickness of usable reservoir isn't increased obviously in the process of polymer flooding. The polymer injection methods with low molecular weigh and high concentration are more fit the Third Class oil layers through analyzing reservoir producing instance under different polymer flooding parameters. To the results of all experimental areas, the enhanced oil recovery may enhance 5 percent through applying polymer flooding technology to the Third Class oil layers.