RESEARCHING AND APPLICATION OF LOW FRICTION CORE BARREL

The conventional core inner barrel which unprocessed have crude face and there are mulsteps in the core passage of barrel because the connections of compound ports of inner core barrel that made the core difficult entering barrel in soft formation coring. The low frictinal core barrel has been developed in which inner face has a lay epoxy resin coating with low frictinai factor by Shengli drilling research institute. The frictinal factor decrease with increasing of load and the hiding structure of core spring barrel with internal flush connections of core passage is adopted. Tnrough ten wells applications,total coring footage is 815.9 meters,avarege core footage per barrel is 789.94 meters and the recovery is 96.82% geater than conventinal tool by 4.16 meters per barrel in footage.