Experimental Study on Aquathermolysis of Different Viscosity Heavy Oil with Superheated Steam

Abstract

In this work, a large number of experiments have been carried out to study the aquathermolysis of heavy oil of different viscosities with superheated steam. First, a high-temperature and high-pressure autoclave was independently designed to carry out an aquathermolysis reaction with superheated steam. Second, the viscosities of the heavy oil samples were measured before and after the aquathermolysis reaction by an MCR 302 rheometer. Finally, both the saturates, aromatics, resins, and asphaltenes (SARA) content and the carbon number distribution of heavy oil samples before and after the aquathermolysis reaction were determined by chromatography. The experimental results show the following: (1) The higher the content of resins and asphaltenes, the longer is the reaction time for aquathermolysis equilibrium. (2) As for different viscosity oil samples, the starting temperature for aquathermolysis is different; however, the reaction temperature for aquathermolysis equilibrium is the same. (3) The cracking of resins is the main mechanism for the aquathermolysis of low-viscosity heavy oil. The cracking of resins is also the dominant mechanism for the aquathermolysis of medium-viscosity heavy oil, accompanied by the cracking of asphaltenes. The cracking of resins and asphaltenes is the primary mechanism for the aquathermolysis of high-viscosity heavy oil. (4) The cracking of long-chain hydrocarbons into short-chain hydrocarbons is the main mechanism of aquathermolysis.

Hydrothermal upgrading of heavy oil in the presence of water at sub-critical, near-critical and supercritical conditions

“…Due to the depletion of conventional light oil resources, the heavy hydrocarbon sources (heavy oils, natural bitumens, etc) will be one of the more promising alternatives to meet the increased demand for energy. However, the difficulty in the production, transportation and processing of these heavy hydrocarbon resources has been a serious problem faced by the operators all over the world because of their high viscosity and low quality resulted from high content of metals and asphalt-resinous components, which contain high content of sulfur, nitrogen and oxygen (heteroatoms) [3][4][5][6]. Heavy oils and bitumens accounts for about 70% of the total proved oil reserves [3,7].…”

Improvement of Steam Injection Processes Through Nanotechnology: An Approach through in Situ Upgrading and Foam Injection

“…After the first steam injection in the absence of nanoparticles, an oil recovery of 63.5% was obtained, and a pressure drop of 10 psi. In this case, the recovery is mainly due to the effect of oil viscosity reduction [69], thermal expansion [70], variation in capillary pressure, and relative permeability of the phases [36], volatilization of light hydrocarbons (C 3 -C 5 ) [71], and gravitational segregation [72] caused by the transfer of steam energy to both fluids and to the porous medium. The steam injection without nanoparticles stopped after the injection of 1 equivalent pore volume of water (PVWE).…”

“…On the other hand, the This is the first measurement, the steam injection generates a %VRD of approximately 7.2%, due to the latent heat transferred by the steam towards the formation fluids, increasing the crude oil mobility, without generating a significant increase in the quality of the same. On the other hand, the catalytic effect of the nanoparticles, their capacity to mediate water-gas shift reactions for the hydrogen production taking advantage of the formation of CO [103], and considering the lower activation energy required to break the C-S bond [112], added to the high electronegativity of S and that the H + ions attack mainly sulfur atoms, with the effect of high pressure and temperature, reactions of aquathermolysis are developed [71], breaking C-S and C = S bonds, interrupting the crude oil viscoelastic network and considerably decreasing crude oil viscosity by approximately 79.39%, 77.60%, and 31.25%, for the three scenarios evaluated, respectively.…”

A novel method for improving recovery of heavy oil reservoirs with high water cut based on polymer gel-assisted CO2 huff and puff

“…It is well known that the geological reserves of heavy oil are much higher than that of conventional crude oil (Huang et al 2018;Guo et al 2016). With the decreasing of conventional crude oil recoverable reserves, the position of heavy oil resources in energy structure is more and more important (Amirian et al 2018;Cao and Gu 2013).…”