{HEAD ~ A first portion} of heavy oil or another feedstock can be deasphalted using propane deasphalting or {TAIL ~ another suitable deasphalting process} 
deasphalted using
{ HEAD ~ A first portion } of heavy oil or another feedstock can be deasphalted using propane deasphalting or { TAIL ~ another suitable deasphalting process }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH REL REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL