Experimental Research on Using Horizontal Well with Chemical Flooding to Exploit Remaining Oil of Side Interlayer after Polymer Flooding

In order to study the influence of horizontal well with chemical flooding on remaining oil of side interlayer after polymer flooding, experiments about high concentration polymer flooding, polymer activator alternating flooding and variable concentration polymer flooding are completed, after determining optimum position of horizontal well and the way of injection and production of water flooding and polymer flooding. Results show that the three methods all can improve recovery efficiency of side interlayer after polymer flooding effectively; horizontal well with variable concentration polymer flooding compared with high concentration polymer flooding, the improved recovery efficiency difference is small because of the same polymer total amount; horizontal well with polymer activator alternating flooding can not only enlarge sweep volume, but also improve the efficiency of wash oil, enhance recovery efficiency obviously, when compared with high concentration polymer flooding, is the best method for remaining oil of side interlayer after polymer flooding.