Injection profile changes analysis of Ⅳ1-3 series during polymer flooding in Shuanghe oilfield

Through injection profiles statistics of Ⅳ1-3 series during polymer flooding in Shuanghe oilfield,the injection profile reversals exist inter and inner-layers.The interlayer injection profile has characteristics of multiple types and large difference.For layers with low permeability,the reversal timing for is late,the reversal frequency is low,the layers with no water injection are more,the accumulative water injection volume and the average water injection intensity are the lowest.The more oil-bearing layers horizontal-ly,the more difficulties in polymer flooding adjustment.From inner-layers water injection status,water injection profiles of river channel and mouth bar sand have cyclical reversals.The inner-layers water injection changes of sand sheet are small,with strong water injection intensity at the bottom of oil layers.According to the research results,profile control or separate injection manner has been suggested so as to increase the producing degree of layers with lowpermeability and improve the development effect by polymer flooding.