Oil Upgrading Research Articles

Use of Nickel Oxide Catalysts (Bunsenites) for In-Situ Hydrothermal Upgrading Process of Heavy Oil.

In this study, Nickel oxide-based catalysts (NixOx) were synthesized and used for the in-situ upgrading process of heavy crude oil (viscosity 2157 mPa·s, and API gravity of 14.1° at 25 °C) in aquathermolysis conditions for viscosity reduction and heavy oil recovery. All characterizations of the obtained nanoparticles catalysts (NixOx) were performed through Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), X-Ray and Diffraction (XRD), and ASAP 2400 analyzer from Micromeritics (USA), methods. Experiments of catalytic and non-catalytic upgrading processes were carried out in a discontinuous reactor at a temperature of 300 °C and 72 bars for 24 h and 2% of catalyst ratio to the total weight of heavy crude oil. XRD analysis revealed that the use of nanoparticles of NiO significantly participated in the upgrading processes (by desulfurization) where different activated form catalysts were observed, such as α-NiS, β-NiS, Ni3S4, Ni9S8, and NiO. The results of viscosity analysis, elemental analysis, and 13C NMR analysis revealed that the viscosity of heavy crude oil decreased from 2157 to 800 mPa·s, heteroatoms removal from heavy oil ranged from S-4.28% to 3.32% and N-0.40% to 0.37%, and total content of fractions (ΣC8-C25) increased from 59.56% to a maximum of 72.21%, with catalyst-3 thank to isomerization of normal and cyclo-alkanes and dealkylation of lateral chains of aromatics structures, respectively. Moreover, the obtained nanoparticles showed good selectivity, promoting in-situ hydrogenation-dehydrogenation reactions, and hydrogen redistribution over carbons (H/C) is improved, ranging from 1.48 to a maximum of 1.77 in sample catalyst-3. On the other hand, the use of nanoparticle catalysts have also impacted the hydrogen production, where the H2/CO provided from the water gas shift reaction has increased. Nickel oxide catalysts have the potential for in-situ hydrothermal upgrading of heavy crude oil because of their great potential to catalyze the aquathermolysis reactions in the presence of steam.

Prospective electric heavy oil upgrading at ambient pressure by high energy electron beam

To alleviate increasing problems of greenhouse gas emissions, two approaches should be deployed: the development of sustainable energy technologies such as wind and solar to reduce the share of fossil fuels, and greener refining and upgrading technologies of fossil/bio-fuels. Here, we introduce an electric method that uses high energy electron beam to achieve heavy oil upgrading in a methane environment at ambient pressure with nearly zero GHG emissions. Two extra-heavy crude oil samples were treated by the electron beam at different conditions. Conversion and yields to gasoline and diesel range fuels were quantified. Detailed economic analysis shown that using low specific energy input (SEI or dose), 500 kJ/kg, <$1.5/barrel, this upgrading process converts heavy fractions (>C40, ∼20 $/barrel) to stable intermediate products (C10–C24, ∼75 $/barrel) in diesel range. No coke was found in treated oil. Product yields (C10–C24) were ∼9 molecules/100 eV, comparable with thermal methods. Sufficient product separation is crucial to the success of this method. This method is electrically driven, easily adaptable to renewable intermittent electricity. It has potentially zero GHG emissions, and is attractive for on-site upgrading of heavy/bio fuels and integration with distributed renewable energy.

Catalytic In-Situ Upgrading of Heavy and Extra-Heavy Crude Oils

Catalytic In-Situ Upgrading of Heavy and Extra-Heavy Crude Oils

Cold Cracking Technology for Crude Oil Upgrading in Qaiyarah Heavy Oil Field; Technical and Economical Evaluation

Heavy oil is classified as unconventional oil resource because of its difficulty to recover in its natural state, difficulties in transport and difficulties in marketing it. Upgrading solution to the heavy oil has positive impact technically and economically specially when it will be a competitive with conventional oils from the marketing prospective. Developing Qaiyarah heavy oil field was neglected in the last five decades, the main reason was due to the low quality of the crude oil resulted in the high viscosity and density of the crude oil in the field which was and still a major challenge putting them on the major stream line of production in Iraq. The low quality of the crude properties led to lower oil prices in the global markets as well as the high operation cost of production and transportation. The purpose of this paper is testing new technology applications on an Iraqi Heavy Oil Field and specifically (Qaiyarah Oil Field) by applying the cold cracking technique to upgrade Qaiyarah heavy oil properties through using series of electrical/ mechanical activities applied on the heavy crude that generates special kind of vibrations to re-structure the (H-C) bonds in the heavy oil to convert it to lighter crude with lower viscosity/ density which was the outcome of the distillation by reducing the unsaturated components and isolating the minerals and sulfur as sold components. The results were very optimistic, where the density has improved from 16 to 30.5 API degree, sulfur content has reduced from 6.4 to 1.507 weight percent and selling price per barrel would increase by 53% compare to 2.31% cost increment due to the upgrading operation. Therefore, applying the cold cracking technology is convenience for improving Qaiyarah oil properties as the main production stream line will be increased in Iraq.

Research and Development Trend of Viscosity Reduction by Catalytic Coupling Reaction of Crude Oil

In view of the increasing consumption of fossil energy, heavy oil with large reserves and wide distribution, as an important unconventional oil and gas resource, has attracted more and more attention in its exploration and development. However, due to the high content of heavy components in heavy oil, its viscosity is high, its fluidity is low, and its quality is poor. Therefore, the key to enhance heavy oil recovery is to reduce its viscosity, improve its fluidity and improve its quality. At present, steam huff and puff, steam flooding and in-situ upgrading and viscosity reduction of heavy oil are the conventional methods for heavy oil recovery. Considering the production cost, the hydrothermal catalytic cracking technology for heavy oil recovery is studied. However, most of these researches only focus on the preparation and application of catalytic viscosity reducer, and there is still a lack of in-depth and systematic research on its specific viscosity reduction mechanism. Therefore, on the basis of abundant active hydrogen provided by alcohol water reforming reaction, it is of great theoretical value and practical significance to design the application of high-efficiency heavy oil viscosity reduction catalyst by using the super molecular interaction of in-situ active minerals and exogenous metal complexes to catalyze the high-efficiency hydrothermal cracking of heavy oil.

Influence of Sodium Metal Nanoparticles on the Efficiency of Heavy Oil Aquathermolysis

In this study, for the first time we investigated the in situ upgrading performance of Na metal nanoparticles, which were obtained by dispersing small pieces of sodium in liquid paraffin up to certain dispersity. In situ aquathermolytic reactions were modeled in a high pressure–high temperature reactor coupled with a Gas Chromatography (GC) system at a temperature of 250 °C for 24 h using a heavy oil sample, produced from the Ashal’cha reservoir, Republic of Tatarstan (Russia). The mean particle size of Na nanoparticles was 6.5 nm determined by the Dynamic Light Scattering (DLS) method. The nanoparticles were introduced to the reaction medium with a concentration of 2 wt.% The upgrading performance of Na nanoparticles was evaluated by several analytical methods such as Gas Chromatography (GC), elemental analysis (CHNS), SARA, Gas Chromatography–Mass Spectroscopy (GC-MS), FT-IR spectroscopy and viscosity measurements. It was revealed that Na nanoparticles interact with water to yield hydrogen gas, the concentration of which increases from 0.015 to 0.805 wt.% Moreover, the viscosity of upgraded heavy oil was reduced by more than 50% and the content of low-molecular-weight hydrocarbons in saturated and aromatics fractions was increased. The Na nanoparticles contributed to the utilization of hydrogen sulfide and carbon dioxide by 99 and 94 wt.%, respectively.

Effect of Ni-Fe/CaO-Al2O3 catalysts on products distribution in in-situ and ex-situ catalytic pyrolysis of Chinese herb residue

It is necessary to investigate the differences between in-situ and ex-situ methods of bimetallic supported catalysts for biomass catalytic pyrolysis. In this paper, the Ni–Fe/CaO–Al2O3 catalysts with different Ni/Fe ratios have been synthesized by coprecipitation method, and it was explored that the effect of products distribution about Chinese herb residue(CHR) catalytic pyrolysis by in-situ and ex-situ methods. The results showed that in-situ NiFe-3 group had the highest content of aromatic compounds (59.68%) and the lowest content of aliphatic compounds (17.67%). This was beneficial to the utilization of chemical raw materials extracted from pyrolysis oil. Meanwhile, the CaO in the catalyst effectively reduces the acid content and corrosion of pyrolysis oil. The results showed that higher Ni and CaO content has the synergistic catalytic action in ex-situ catalytic experiments. It could promote water-gas shift reaction, which is conducive to the generation of H2. In-situ catalysis is mainly used for the upgrading of pyrolysis oil, while ex-situ catalysis is mainly used to promote secondary pyrolysis of pyrolysis products and improve the quality of pyrolysis oil. This work provides reference for the difference and high value utilization of biomass pyrolysis by different catalytic methods.

Influence of FeP and Al(H2PO4)3 Nanocatalysts on the Thermolysis of Heavy Oil in N2 Medium

The high viscosity of heavy oil is the main challenge hindering its production. Catalytic thermolysis can be an effective solution for the upgrading of heavy oil in reservoir conditions that leads to the viscosity reduction of native oil and increases the yield of light fractions. In this study, the thermolysis of heavy oil produced from Ashalchinskoye field was carried out in the presence of FeP and Al(H2PO4) nanocatalysts at a temperature of 250 °C in N2 gas environment. It was shown that Al(H2PO4)3 and FeP catalysts at a concentration of 0.5% significantly promoted the efficiency of the heavy oil thermolysis and are key controlling factors contributing to the acceleration of chemical reactions. The Al(H2PO4)3 + NiCO3 nanoparticles were active in accelerating the main chemical reactions during upgrading of heavy oil: desulfurization, removal of the side alkyl chains from polyaromatic hydrocarbons, the isomerization of the molecular chain, hydrogenation and ring opening, which led to the viscosity reduction in heavy oil by 42%wt. Moreover, the selectivity of the Al(H2PO4)3 + NiCO3 catalyst relative to the light distillates increased up to 33.56%wt., which is more than two times in contrast to the light distillates of initial crude oil. The content of resins and asphaltenes in the presence of the given catalytic complex was reduced from 34.4%wt. to 14.7%wt. However, FeP + NiCO3 nanoparticles contributed to the stabilization of gasoline fractions obtained after upgraded oil distillation. Based on the results, it is possible to conclude that the thermolysis of heavy oil in the presence of FeP and Al(H2PO4)3 is a promising method for upgrading heavy oil and reducing its viscosity.

Catalytic Low-Temperature Thermolysis of Heavy Oil in the Presence of Fullerene C60 Nanoparticles in Aquatic and N2 Medium

Catalytic thermolysis is considered to be an effective process for viscosity reduction, the conversion of high-molecular components of oil (resins and asphaltenes) into light hydrocarbons, and the desulfurization of hydrocarbons. In this paper, we conducted non-catalytic and catalytic thermolysis of a heavy oil sample isolated from the Ashalcha oil field (Tatarstan, Russia) at a temperature of 250 °C. Fullerene C60 nanoparticles were applied to promote selective low-temperature thermolytic reactions in the heavy oil, which increase the depth of heavy oil upgrading and enhance the flow behavior of viscous crude oil. In addition, the influence of water content on the performance of heavy oil thermolysis was evaluated. It was found that water contributes to the cracking of high-molecular components such as resins and asphaltenes. The destruction products lead to the improvement of group and fractional components of crude oil. The results of the experiments showed that the content of asphaltenes after the aquatic thermolysis of the heavy oil sample in the presence of fullerene C60 was reduced by 35% in contrast to the initial crude oil sample. The destructive hydrogenation processes resulted in the irreversible viscosity reduction of the heavy oil sample from 3110 mPa.s to 2081 mPa.s measured at a temperature of 20 °C. Thus, the feasibility of using fullerene C60 as an additive in order to increase the yield of light fractions and reduce viscosity is confirmed.

Experimental Study on Optimizing Steam Solvent Co-Injection Process in Akan Carbonate Oilfield

Steam solvent co-injection processes are generating considerable interest in terms of improving heavy oil upgrading in unconventional reservoirs. The characteristics of the opted solvents in the field have not been dealt with in depth. This paper presents a study on selecting the most optimal solvent for the Akan oilfield enhanced oil recovery (EOR). The first step in this work consisted of determining the Akan oil field viscosity, through an elemental and SARA analyses. Next, a set of physical and chemical methods was used to understand the mechanism of solvents’ effect on oil viscosity dynamics. The compositions of the used solvents were analyzed by a gas chromatography-mass spectrometer system equipped with a mass selective detector ISQ (USA). The evidence from the present study suggests that toluene and o-xylene are the most optimal solvents for enhancing the Akan oil recovery and reducing its viscosity. The obtained data demonstrated a higher efficiency of the used solvents on the oil viscosity reduction where the maximum oil viscosity reduction was observed in the presence of toluene, which led to a value of 178.1 mPa.s. Moreover, the obtained results reported that the solvent co-injection process efficiency increases gradually depending on the chemical composition of the used solvent, as witnessed by the obtained oil recovery factor (RF) values. It has been found that the oil recovery factor values during the capillary soaking in the presence of water was equal to 20%, in the presence of o-xylene it was equal to 61%, and in the presence of toluene, it was equal to 69%. Likewise, a similar efficiency behavior has been demonstrated during filtration experiments where water led to a 26% recovery factor, o-xylene to 69%, and toluene to 78%, meanwhile the solvent slug led to 65%. The results of this study would seem to suggest that the viscosity of the investigated oil decreases in the presence of aromatic solvents, such as toluene and o-xylene, as witnessed by the recovery factors they demonstrated. A consequence of these changes is the possibility that aromatic solvent molecules tend to separate the asphaltene layers and reduce the overlap between large asphaltene macromolecules, which leads to the dissociation of asphaltene aggregates.

Strategies for adding tetralin in thermal processing of heavy oil

The strategy of adding tetralin as a H-donor in the thermal processing of heavy oil was investigated by experimental characterization and theoretical calculations. According to the experiments, the timing of adding 1 wt% of tetralin has a great influence on the visbreaking performance of heavy oil. Calculations based on density functional theory showed that benzyl radicals released from the thermal cracking of tetralin accelerate the dealkylation that determines the heavy oil upgrading. Meanwhile, Hα provided by tetralin is able to selectively saturate aromatic C radicals which are essential for condensation. Compared with the conventional H-donor addition, i.e., pre-mixing of tetralin with heavy oil, a similar viscosity reduction rate of about 98% can be obtained during the visbreaking with delayed tetralin addition. Furthermore, the addition of tetralin before the significant occurrence of condensation further increases the conversion of vacuum residue fraction by 3.4% and reduces the asphaltene content of the product by 2.6 wt%.

Solute structure effect on aromatics-alkanes extractive separation toward rational LCO upgrading

Unravelling solute effect on extractive separation of aromatics and alkanes is highly required toward its rational incorporation into economical upgrading of light cycle oil (LCO). This work systematically examines the effect of aromatic and alkane structures on extraction performance from experimental and theoretical perspectives. Liquid-liquid extraction experiments demonstrate that the distribution coefficient and extraction efficiency strongly depend on the aromatic structure, whereas the selectivity and theoretical purity of aromatics significantly rely on the alkane structure. The extraction mechanism is elucidated from interaction strength and interfacial thickness analysis using molecular dynamics simulation. The diaromatics of 1-methylnaphthalene has stronger affinity to deep eutectic solvent (DES) than the monoaromatics of tetralin, while longer alkyl-chain in hexadecane enhances its repulsive interaction with DES than dodecane. Extraction process simulation was then carried out with well-regressed parameters of NRTL thermodynamic model. Process simulation confirms that a high extraction performance can be achieved for model LCO containing more diaromatics. Therefore, it is preferable to incorporate aromatics-alkanes extractive separation into the pre-hydrotreating step of LCO upgrading process.

CONVERSION OF NIGERIAN OILSAND TO LIGHT CRUDE IN THE PRESENCE OF ENHANCED FLUID CATALYTIC CRACKING (FCC) CATALYST.

Conversion of heavy oil to light crude in the presence of a catalyst better known as catalytic upgrading of heavy and extra-heavy oil is been explored worldwide as one important in-situ upgrading technology among others. In this study, an equilibrated Fluid Catalytic Cracking (FCC) catalyst was sourced from a refinery, enhanced by the addition of transition metal ions, characterized using X-Ray Diffractometer (XRD), X-Ray Flourencence (XRF) and Fourier Transform - Infrared (FT-IR) techniques and tested in upgrading heavy crude oil. The enhanced FCC (Fluid Catalytic Cracking) commercial catalyst, hydrogen and glycerol were added into bitumen (32000cSt measured at 40oC) in a high-pressure batch reactor at 350oC for reaction time of two hours, pressure of 10bar and catalyst to bitumen ratio of 0.02. Viscosity reduction after thermal upgrade were 83 and 98% at room temperature and at 40oC respectively while the reduction after catalyst upgrade were 87.9 and 98.9% correspondingly under the same conditions. It was found that there was improved API gravity from 11.6 to 26.0 in thermal reaction and 30.5 in catalytic reaction. Other physiochemical properties of the bitumen investigated also improved significantly towards the production of lighter oil. The structural compositions of the bitumen before and after the reaction at 350oC were investigated using Fourier Transform - Infrared (FT-IR) and Gas Chromatograph – Mass Spectrometer (GC-MS). The result shows that the heavy molecular compounds like resins and asphaltene were broken down to lighter compounds. Keywords: Bitumen, Oilsand, Fluid Catalytic Cracking, Catalyst, Heavy oil, Upgrade.

Enhanced Oil Recovery by In-Reservoir Hydrogenation of Carbon Dioxide Using Na-Fe3O4

In-situ conversion of carbon dioxide into value-added products is an essential process in terms of heavy oil upgrading and utilization of the main anthropogenic greenhouse gas. In this paper, we discuss a synthesis of sodium-coated magnetite (Fe3O4) particles for in-reservoir hydrogenation of CO2. The performance of the obtained catalyst was tested in upgrading of heavy oil in a High Pressure/High Temperature (HPHT) reactor imitating the reservoir conditions during steam injection techniques. The experiments were conducted for 48 h in a CO2 environment under the steam temperature and pressure of 250 °C and 90 bar, respectively. The results showed irreversible viscosity reduction of oil from 3931 mPa.s to 2432 mPa.s after the degassing of unreacted carbon dioxide. The content of resins in the composition of upgraded oil was significantly altered from 32.1 wt% to 19.01 wt%, while the content of aromatics rose from 32.5 wt% to 48.85 wt%. The GC-MS results show the presence of alkyl benzenes and phenanthrenes, which were initially concentrated in resins and asphaltenes, in the aromatics fraction of upgraded crude oil. Thus, Na-Fe3O4 exhibits promising results for in-situ heavy oil upgrading through the hydrogenation of carbon dioxide, which contributes not only to the reduction of greenhouse gas emissions, but also enhances heavy oil recovery.

Performance of Structural Alloys in Bio-oil Production, Upgrading, and Storage Systems

Selection of corrosion-resistant, cost-effective structural materials for the process and containment vessels required for the production, upgrading, and storage of biomass-derived oils has been the subject of study in our laboratory for many years. The wide variety of biomass resources and the many liquefaction techniques and processing conditions result in products with a broad range of properties and compositions. This paper will address the materials issues in three distinct areas. In production, materials are exposed to temperatures that range from 350 to 550 °C depending upon the process. Generally, austenitic stainless steels have performed reasonably well, although thicker oxide scales and intergranular attack have sometimes been observed. For storage and transport of the bio-oil products, temperatures experienced by the containment materials are not expected to exceed 50 °C. Our studies have shown that most raw bio-oils contain significant concentrations of organic acids, and low-molecular-weight organic acids were quite corrosive to carbon and low alloy steels. For some applications, subsequent processing is required, which includes hydrotreating or co-processing with a petroleum-derived liquid. These processes utilize a catalyst that requires periodic retreatment with a sulfidizing gas, and the exposure to this gas at elevated temperatures can cause appreciable corrosion to the more common austenitic stainless steels. The materials considered most cost-effective and sufficiently corrosion-resistant for each of these environments were identified.

In-situ heavy oil upgrading by high temperature oxidation through air injection

Air injection has been widely considered as a technology to enhanced heavy oil recovery on account of the heavy oil upgrading caused by high temperature oxidation during this process. This paper aims at exploring the effects of oxidation thermal processing in a porous media at high temperature from 500 to 540℃ which is the high temperature oxidation range of heavy oil known from TG results, and reaction time from 8 to 16 hours for heavy oil upgrading. It was suggested that the viscosity decreased with the temperature and retention time increased due to getting less ring structure seen from IR Spectrum results. It was observed that the viscosity of heavy oil was reduced 1 to 2 orders of magnitude. Besides, the kinetics of heavy oil upgrading were analysed using five pseudo components including HO (C35+), MO (C15 ~ C35), LO (C5 ~ C14), coke, G (gas products) and successfully predicted the products results with an error of 4.34%, and great correlation to Arrhenius equation. The activation energies obtained are in the range of 44 ~ 215 kJ/mol. This work has great value in revealing the mechanisms of high temperature oxidation heavy oil upgrading and assisting heavy oil production.

Innovative Experimental Design for the Evaluation of Nanofluid-Based Solvent as a Hybrid Technology for Optimizing Cyclic Steam Stimulation Applications

Worldwide gas emissions are being strictly regulated, therefore processes to reduce steam injection for enhanced oil recovery (EOR) require a deeper analysis to identify the means to contribute to environmental impact reduction. Lately the usage of additives such as a solvent for steam injection processes has taken a new interest due to its positive impact on improving oil recovery and energy efficiency and reducing greenhouse gas emissions. In that sense, the use of nanoparticles in thermal EOR has been explored due to its impact on avoiding the volatilization of the solvent, offering greater contact with the oil in the reservoir. Nanoparticles have well-known effects on asphaltenes adsorption, aquathermolysis reactions, oil upgrading, and improving energy efficiencies. This article presents a summary and ranking of the nanoparticles evaluated in nanofluid-based solvent for steam processes, specifically in the catalysis of aquathermolysis reactions. A novel experimental design is proposed for the characterization, formulation (based on catalytic activity and dispersion), and evaluation of solvent improved with nanoparticles. This new approach will be used as a guideline for the evaluation of nanoparticles dispersed in hydrocarbon-type solvents as a hybrid technology to improve steam injection processes.

The effect of chlorella hydrothermal products on the heavy oil upgrading process

In-situ upgrading can improve the scale of heavy oil development, but the efficiency of in-situ hydrothermal hydrogen supply is limited. In this paper, the combination of algae hydrothermal liquefaction and heavy oil upgrading and viscosity reduction process is proposed. The liquefaction products of hydrothermal liquefaction are used to supply hydrogen to the heavy oil upgrading and viscosity reduction process, thereby enriching the supply path of active hydrogen. The effects of hydrothermal liquefaction temperature of Chlorella and the addition of 5% Fe/HZSM-5 catalyst on the liquefaction rate and product distribution of Chlorella were investigated, and the upgrading and viscosity reduction process of heavy oil with the participation of hydrothermal liquefaction products was discussed. The results show that when the temperature of upgraded heavy oil is 280 °C and 5 wt% of hydrothermal liquefaction products are added and reacted for 24 h can make the viscosity reduction rate of heavy oil reach 84.32%, and 31.2% of resin in heavy oil was converted into aromatic hydrocarbon. Elemental analysis showed that the upgraded heavy oil H/C ratio increased, and GC–MS analysis showed that the distribution of algae hydrothermal liquefaction products could be adjusted by the catalyst, and more aromatics were produced after the addition of the catalyst, which confirmed that the aromatics in hydrothermal liquefaction products had a significant effect on the quality improvement and viscosity reduction of heavy oil. Its molecular weight was also found to be reduced from 853 to 326 in the average molecular weight test (GPC). The efficient carbon sequestration of algae is combined with the demand for carbon dioxide emission reduction in oilfields to realize the recycling of carbon resources.

Experimental investigation of enhanced oil recovery and in-situ upgrading of heavy oil via CO2- and N2-assisted supercritical water flooding

Exploitation of heavy oil is critical for mitigating the energy crisis. However, conventional thermal recovery methods cannot completely exploit the potential of heavy oil owing to its high viscosity and heavy distillates. A new technology is proposed with reference to CO2– and N2-assisted supercritical water (MGA-SCW) injection for heavy oil recovery. In this study, an experimental apparatus was developed to simulate the MGA-SCW flooding process and test its feasibility. MGA-SCW injection remarkably enhanced oil recovery, increased the oil production rate, and improved the oil quality. For MGA-SCW flooding at 25 MPa and 400 °C, the recovery factor approached 95 %, and the oil viscosity decreased by 32 %; the light distillate fraction (180–350 °C) increased from 11 to 15 %. The dynamic process of MGA-SCW flooding is divided into three stages: pressure difference, thermal, and miscible drives. This technology can be applied to the development and utilization of offshore heavy oil fields.

Kinetic study of asphaltenes phase separation in supercritical water upgrading of heavy oil

Supercritical water upgrading heavy oil is a promising way to produce light oil and gas. To understand the reactions pathways and the role of supercritical water during the upgrading process, experiments were carried out in a batch reactor at 380–440 °C and reaction times up to 2900 min. The products were classified as gas, coke and liquid products which were further separated into saturates, aromatics, resins and asphaltenes. A kinetic model including aromatics and resins partially dissolved in both supercritical water phase and oil phase was developed. This model could fit experimental data well and interpret effects of supercritical water solubility for aromatics and resins on heavy oil upgrading process. Further, supercritical water upgrading process was divided into three stages: pre-induction primary cracking stage, post-induction primary cracking stage and gas-generation stage. This work provides an in-depth understanding of mechanism of heavy oil upgrading in supercritical water.