Experimental Study Of Upgrading Heavy Oil By Vapor Extraction And Model Analysis About Related Research

Vapor extraction-VAPEX is a new recovery method which has been proposed in recent years. It developed from SAGD. Because of the advantages of low-energy, low-cost and eco-friendly, and can also upgrade the reservoir oil, the VAPEX has become an oil deposit recovery technology which has a broad application prospect.In this paper, the heavy oil of Liaohe Oilfield(Du 66 Block) is the main study object. The thesis compared the property and structure change of heavy oil before and after the vapor extraction, and also had a research on the crude oil upgrading from the microscopic and macroscopic perspective. Conducted a laboratory test to analyze the mass transfer coefficient during the extraction process to optimize the most excellent operating condition and solvent mixture. And also researched the reaction mechanism of boundary layer, and summarized the diffusion and natural model.First of all, the relationship of extraction rate and pore medium through different mediums extraction experiments, then compared the property and structure change of heavy oil before and after the vapor extraction have been studied. This paper studied the influence of solvent extraction to heavy oil upgrading and viscosity reduction ability from microscopic and macroscopic perspective by the methods of group composition, element content, viscosity-temperature relationship, infrared spectroscopy, analysis of hydrocarbon and so on.Secondly, have experimentally studied the mass transfer coefficient of different solvent system in different operating conditions. It turned out that the solvent’s mass transfer coefficient in high temperature and pressure is better than that in normal temperature and pressure; In the same high temperature and pressure, the mass transfer coefficient of mixed solvent is higher than pure solvent.Finally, through the equation calculation, researched the natural convection effect of mixture in the boundary layer, the relationship of solvent strength and viscosity, as well as the formation of boundary layer. Summarized the related theories of diffusion coefficient, and concluded the mathematical model between diffusion coefficient and concentration.