STUDY ON THE THREE-LAYER SPHERICAL CAPSULE GEL BREAKER

The three-layer spherical capsule gel breaker is made of capsule nucleus,mantle and shell,which are cohered together by physical method.The main composition of nucleus and mantle is ammonium persulfate.The capsule shell is made from polymer,which has good performances of water insulation,heat resistance and slow oil-solubility.This gel breaker can isolate jelly fracturing fluid from ammonium persulfate gel breaker.Large dosage and high concentration use of gel breaker can not early break down the performance of fracturing fluid such as rheological property,filter loss and prop-carrying capacity.Compared with the existing techniques,it not only increases the used concentration,but also has advantages of delaying release,triggering overall release and good effectiveness of gel breaking.