Control release capsules comprising {HEAD ~ a breaker} contained within {TAIL ~ a enclosure member} are employed to break fracturing fluids 
contained within
Control release capsules comprising { HEAD ~ a breaker } contained within { TAIL ~ a enclosure member } are employed to break fracturing fluids
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH