Study On The Resistivity Model Of Water-Flooded Zone In Thick Oil Reservoirs During High Water Cut Stage

With the increasing of oilfield development and waterd-out degree, the difficulty of logging interpretation about watered-out zone is more growing. Then how to have the study on the distribution rules of remaining oil based on the characteristics of high water cut stage will be an important factor, which will affect the stable yields and development for Daqing Oil Field. Consequently it is necessary to carry out the quantitative interpretation research on the watered-flooded zone, in accordance with the characteristics of the latter part in the oilfield exploration. In this paper an effective medium resistivity model for the watered-flooded in thick oil reservoirs during high water cut stage has been proposed, based on the electric petrophysical experiment in the condition of the water flooding ,polymer-flooding and alkali-surfactant-polymer flooding,the symmetrical anisotropic effective medium theory, research on log response characteristic and the conductance mechanism in water flooding,polymer-flooding and alkali-surfactant-polymer flooding reservoir. By analyzing effects of some factors on the proposed model and validations with experimental measurements of rock samples, How to solve the remaining oil saturation was studied by the method of the proposed model.Based on the relations between analysis for rock core and log response characteristic, The parameter interpretation model of pore, permeability and bound water saturation have been proposed in thick oil reservoirs, and the interpretation software was compiled. The interpretation results of some wells using the proposed model are given, and are compared with test results. It is shown that the water saturation calculated with the model is reasonable and it can improve the accuracy of the evaluation for the watered flooded zone, and make the quantitative interpretation to be achieved.