Experimental Studies Of Physical Simulation On Polymer Flooding In The Large-scale Areal Models

In Daqing Oilfield, the polymer flooding has been earlier used in our country. And from theoretical research indoors to pilot tracey in situ and industrial usage, a large amount of achievement has been gained actually. However, because of the complexity of polymer flooding, it is not clear to us with the mechanisms of oil-displacement. Two influencing factors on the distribution of residual oil after polymer flooding are the oil-displacement efficiency and the swept volume. Given that, when the remained oil distribution after polymer flooding was described, the effects of enhancing oil-displacement efficiency and altering swept volume and the influencing factors should first be studied. Nowadays, all the researches about the polymer flooding were basically in terms of the methods of numerical and one-dimensional physical simulation, while this kind of studies which were conducted in areal models was minor. In addition, it has never been reported about the measurement of the oil-displacement and the sweep efficiency and their effects on enhanced oil recovery.In this paper, based on the similarity theory, the similarity criterion of polymer flooding was constructed with the method of equation analysis. And the criterion was checked in and the sensitivity was analyzed, which determined the norm figure with bigger influence on experiments. Combined with the influence of different lengths of models on recovery, it can be concluded that: If we want to achieve the reasonable contribution to the recovery through enhancing the oil-displacement efficiency and enlarging the swept volume, the influence of the uncertainty of the system and the end face effect. Thus, we should use longer cores ( not less than 30cm) or larger areal models to carry out the relative experimental studies.The large-scale physical models ( 60cm× 60cm× 4. 5cm) has been actually made out. And the method on measuring oil-water saturation with micro-electrodes has also been successfully constructed, which has been used into the oil-displacement experiments in the areal physical models to study the alteration of oil-displacement and sweep efficiency and the relative dynamical characteristics of polymer flooding.