wherein {HEAD ~ a weight ratio} in {TAIL ~ the mixture} of the first heavy oil fraction relative to the deasphalting residue is from 30:70 to 70:30, and further comprising up to 10 wt % of an alkyl substituted aromatic sulfonic acid, 
in
wherein { HEAD ~ a weight ratio } in { TAIL ~ the mixture } of the first heavy oil fraction relative to the deasphalting residue is from 30:70 to 70:30 , and further comprising up to 10 wt % of an alkyl substituted aromatic sulfonic acid ,
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH