Experiment of parameters optimization for plug removal by rotating jet flow in sand-control horizontal wells

A particular experimental device was designed to perform experiments on plug removal by rotating jet flow with actually plugged sand-control screens removed from horizontal wells in the Gudao oilfield.With this experiment,qualitative relationships of plug removal effects with construction parameters,such as plug remover types,pumping rate and moving mode,were examined and their sensitive regularity was analyzed as well.Finally,a reasonable plug removal and its corresponding parameters were recommended by optimizing construction parameters of plug removal,and this method involved a fashion ofintermittent moving and stayinginstead of the previous one ofuniform-velocity moving.An optimal distance for every advance is 1.5~2 m with staying time for 2~4 min,which can produce a better plug removal effect.During plug removal,the higher the pumping rate,the better the plug removal effect can be gained,thereby a real pumping rate should not be less than550~600L/min.In addition,the use of a compound-acid plug remover could gain a more even effect of plug removal.The comparison experiment indicated that compound acid tends to remove screen plug more efficiently than clean-water fluid and the plug removal effect of severely plugged screens is better than that of slightly plugged screens.So,the technique of plug removal by rotating jet flow should be applied preferentially to the severely plugged sand control horizontal wells.