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