Method of saving string of {HEAD ~ tools} installed in {TAIL ~ an oil well} and a corresponding transmission assembly 
installed in
Method of saving string of { HEAD ~ tools } installed in { TAIL ~ an oil well } and a corresponding transmission assembly
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH