Study On Polymer Flooding Changes Of Rock Physical Parameters Of The Water Flooded Layer Of Gudao Oilfield

Polymer flooding technologyhas has been being perfected gradually and widely applied in China. In the past, the main research at home and abroad focused on polymer properties,the characteristics of logging response after polymer flooding and its mechanisem analysis attracted more attention. The reservoir was eroded by injected fluid at different development period. The injectd polymer flow through the reservoir and residue in it because the different properties between polymer flooding and water flooding, which leads to obvious changes in properties of the rock physics(porosity, permeability, saturation, beam) and formation fluid.We obtaind the samples at different development stages of polymer flooding by experimental simulation in lab. The porosity, permeabilty, lithology, wettability, saturation and micro-structure of samples were measured before and after polymer flooding. The variation of the properties were analyzed and summerized. We studied the characteristics of logging curve such as spontaneous potential, resistivity, porosity and analyzed the mechanism. The models of the shale content, porosity, permeability, water saturation, bound water and residual oil saturation, relative permeability were proposed. The water production rate model and its accuracy were investigated. The relationship between logging response characteristics,reservoir petrophysical properties and electrical properties was analyzed. It will improve the estimation accuracy of porosity, permeability and saturation, interpretation accuracy of the long-term water flooding and polymer flooding reservoir.