Numerical simulation and experiment on the technology for dispersing chemicals in heavy oil

The fluids in heavy oil pipelines are characterized by high density and high viscosity. To deal with these characteristics, three chemical injection structures (i.e., high-pressure countercurrent chemical injection structure, microtube chemical injection structure and micropore chemical injection structure) and three mixing structures (i.e., inner cone cylinder mixing structure, partition mixing structure and cycling plate mixing structure) were designed in this paper. Then, CFD simulation was carried out on above-mentioned chemical injection and mixing structures to optimize their structure parameters and analyze their chemical dispersion performance. It is shown that the chemical and the heavy oil cannot be fully mixed if only chemical injection structure is adopted; the chemical dispersion performance of micropore injection structure is the best; the performance of inner cone cylinder mixing structure is optimum if the pressure drop and the chemical dispersion performance are taken into consideration comprehensively. Finally, laboratory experiments were conducted on these mixing structures to test their performance. It is indicated that the pressure drop generated by the mixing structures is in negative correlation with the chemical dispersion effect and the chemical dispersion effect is affected by the concentration of the chemical. Obviously, the experimental results are consistent with the simulation results. Thus, the medical feeding mode suitable for heavy oil pipelines is determined on the basis of CFD simulation and experimental study, i.e., the circumferential micropore injection structure outside the pipeline and the inner cone cylinder mixing structure inside the pipeline.