... was 9491.24m 3 , and the profile modification radius was 20m, approximately corresponding to 0.0065PV of pore volume for the well cluster tested. Injection pressure rises steadily during operation During injection of nitrogen foam, the injection pressure of each of three wells rises in a varying range...

... No. of injectors Responding time, d Water breakthrough, d Max Min Avg Max Min Avg 35 109 1 55 330 85 200 Table 2 Comparison of results from different profile modification methods Well pattern Methods Concentration, ppm Incremental oil, 10 4 m 3 A21 Single slug 3000...

...) injection of high concentration slug; 2) polymer injection to separate layers; 3) in depth profile modification. The success of these techniques and processes have enlarged the polymer flooding scale year by year and the technology of polymer flooding itself has been improved. The successful experience...

.... This is caused by uneven water sweep due to severe reservoir heterogeneities. Unfortunately, there are no in-depth profile modification agents that can stand such harsh reservoir conditions. To address the problem, a novel process is developed which takes advantage of the multi-valence cations concentrated...

... flooding. Generally speaking, it is very hard to obtain the current reservoir permeability data. Only the native permeability, which has great diversity with the actual reservoir conditions, can be considered in profile modification. So a lot of problems usually exist in the process program designed...

... strength in-depth profile modification with ultra high molecular weight polymer flooding’ is applied to a commercial polymer flooding project conducting in this oil zone, which would finally result in an increase in oil recovery efficiency by 10% OOIP. This paper introduces the design features...