Experiment Research On Homogeneity Oil Layers EOR By Steam Flooding After Polymer Flooding

Aimming at the current status of exploitation of the homogeneity thin oil layers,in order to achieve the purpose of enhancing oil recovery after polymer flooding,we proceed the steam flooding experiments after the polymer flooding in laboratory,and researched the effect of the different steam injection temperature and different steam injection velocity and permeability contrast to enhancing oil recovery.By means of experiments of six temperature which covered from 100℃～200℃,the result indicated:when the temperature of steam injection is 100℃,the recovery is only 2%,when the temperature of steam injection is 200℃,and the recovery is 29.5%,the range of recovery advance significantly from 120℃～140℃;By means of experiments of four different steam injection velocities,the result indicated: the recovery is the lowest while the steam injection velocity is minimum(0.04ml/min), the recovery is the highest while the steam injection velocity is maximum(0.24ml/min) ,the difference between them is 6.4% at most;.By means of steam injection experiments of different backpressure,the result indicated :the effect of steam flooding after the polymer flooding is influenced by backpressure,the recovery difference is great under the different backpressure with the same temperature ,in the condition of different backpressure,the recovery can enhance significantly when the average temperature of the rock exceed 10～15℃than the temperature of saturated steam;By means of experiments of the rock of three kinds of permeability,the result indicated :in the condition of the same temperature and velocity,the recovery of rock that the permeability of which is 2000×10-3μm2 is the highest,the recovery of rock that the permeability of which is 300×10-3μm2 is the lowest,and the recovery of rock that the permeability of which is 900×10-3μm2 is in the middle of them; By means of economic analysis of the experiment result,it indicated that oil-gas ratio can achieve 0.1 in the condition of the appropriate temperature and pressure.