RESEARCH AND APPLICATION OF TECHNIQUE FOR PLUGGING LARGE PORE PATH IN SANDSTONE RESERVOIR AT HIGH WATER CUT STAGE

Based on the investigation to the geologic features and development history of Wen and Ma Oil Fields,this paper analyzes the origin of large pore path.In view of the high permeability,large throat radius,good connection among injectors and producers and so on,this paper conducts screening to the sort and concentration of water shutoff agent and evaluation on its property.The original profile control process is improved.Field test is carried out.Technique for plugging large pore path is formed and completed gradually.Since 1997,the technique has been used to plug large pore path in 25 wells.The accumulated incremental oil production is 7303 t,the accumulated water production decreased by 29 922 m3,and the input-output ratio is 1:3.7.The problem of plugging large pore path has been solved.