Optimizing Viscosity Reduction of Sherq Baghdad Heavy Crude Oil: A Comparative Study of Naphtha, Toluene, and Kerosene Diluents

Heavy crude oil transportation is severely limited by high viscosity, creating major operational and economic challenges.This study investigates viscosity reduction of Iraqi heavy crude oil from the East Baghdad field using dilution with light hydrocarbons.Three solvents-kerosene, toluene, and naphtha-were tested at concentrations of 5-20% v/v under controlled temperatures (21, 40, and 62 C) and mixing times (30 and 60 min).Viscosity measurements were conducted using a capillary viscometer following ASTM D445.The results demonstrate that viscosity reduction is strongly influenced by solvent type, dosage, temperature, and mixing time.Naphtha emerged as the most effective diluent, achieving up to 60% reduction at 20% v/v, while toluene and kerosene showed lower but still significant effects.The combined influence of solvent choice and operating conditions highlights the importance of optimization for field application.These findings provide a practical, data-driven basis for improving pipeline transport efficiency and reducing operational costs in heavy crude handling, while also pointing to future work on cost-benefit evaluation and environmental considerations.