In-Situ Upgrading Research Articles

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

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

Global Trends in Heavy Oil and Bitumen Recovery and In-Situ Upgrading: A Bibliometric Analysis During 1900–2020 and Future Outlook

Abstract Bitumen and heavy oil are energy resources with high viscosities, high densities, and high metals and heteroatoms content. This paper reports a bibliometric survey to investigate the historic trends and the future pattern of heavy oil and bitumen recovery and upgrading worldwide. It evaluates research outputs and their impact on the topic from 1900 to 2020. Data were extracted from Web of Science (WoS), vetted using Microsoft Excel, and visualized using VOSViewer. Globally, the study identified 8248 publications. Canada had the highest research output and was also widely cited, and the highest-productive countries are the United States from 1900 to 1970, Canada from 1971 to 2000, Canada from 2001 to 2010, and China from 2011 to 2020. The keywords frequency suggests that most research on heavy oil and bitumen focuses more on viscosity reduction, rheology, asphaltenes, enhanced oil recovery methods, and upgrading. These are the top five most productive institutions in the field: University of Calgary > China University of Petroleum > University of Alberta > Russian Academy of Sciences > China National Petroleum Corporation. The Universities of Calgary and Alberta are, however, the most frequently cited and most impactful, with respective citations and h-indexes of 10367 (50 h-index) and 8556 (47h-index). The future of heavy oil and bitumen depends on crude oil price, the economics of transportation alternatives, climate change policies and technologies, while the design of robust and low-cost catalysts would guide in-situ catalytic upgrading.

In-Situ upgrading technology: Nanocatalyst concentration levels effects and hydrocarbons paths in the porous medium

The current research work contributes one further step in developing the heavy oil in-situ upgrading technique. The experimental work was carried out using a dolomite corepack as a porous medium at temperature and pressure already investigated in In Situ Upgrading Technology (ISUT). Crude oil was saturated in the corepack to simulate the oil in place in the reservoir; then, hot vacuum residue (VR) plus nanocatalyst, and in the presence of hydrogen (H2) was continuously injected into the porous medium. The nanocatalyst was composed of ultradispersed Ni–Mo and deposited in three incremental steps in the corepack. Depositing catalyst in the corepack aimed to create a reactor in which upgrading reactions can occur. After each incremental nanocatalyst deposition step, the hot VR and H2 continuously flowed at a selected temperature, pressure and residence time through the corepack. The products of every VR plus H2 step were analyzed with techniques such as microcarbon (MCR), simulated distillation (SimDist). The products from the stage with the highest catalyst concentration were determined to have lower VR contents, much lower viscosities, lower sulfur content, and stability; this latter indicating the necessity of carefully controlling processing severity levels. Chemical tracers were added to the crude oil (Phenanthrene) and the VR (1-methylnaphthalene and n-octadecane) at a 1.0 wt% level; their distributions were studied throughout the process via chromatography and mass spectrometry analyses. Cracking, plus olefin and aromatic hydrogenation reactions were evidenced to occur during the ISUT process.

Insights into In-Situ Upgrading of Bitumen in the Hybrid of Steam and Combustion Process: From Experimental Analysis Aspects

Insights into In-Situ Upgrading of Bitumen in the Hybrid of Steam and Combustion Process: From Experimental Analysis Aspects

Insights into In-Situ Upgrading of Bitumen in the Hybrid of Steam and Combustion Process: From Experimental Analysis Aspects

Insights into In-Situ Upgrading of Bitumen in the Hybrid of Steam and Combustion Process: From Experimental Analysis Aspects

In-situ upgrading in a dolomite porous medium: A kinetic model comparison and nanocatalyst deposition study

Heavy oil extraction currently presents economic and environmental challenges due to low prices and costly energy usage for their exploitation and transport. The use of heavy oil as a sustainable source of energy requires novel and well-engineered technologies. In-Situ (in-reservoir) Upgrading Technology, ISUT, is an EOR-Upgrading process that combines the use of a hot dense fluid (i.e., vacuum distillation residue), hydrogen, and a nanocatalyst as upgrading agents. The operating control of this technology requires performance assessment and kinetic database for each application and each type of reservoir with specific rock-oil in place characteristics. In this work, a hydrocracking kinetic study is developed based on experiments carried out in a dolomite corepack using temperatures from 335 °C to 365 °C, residence times of 12 h–72 h under the constant pressure of 10 MPag, which are the typical ISUT's conditions for carbonate reservoirs. By using kinetic modeling, the operating temperatures were compared with a previous kinetic model, finding similar yields/reaction time performance results. Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray spectroscopy (EDX) techniques were used to analyze the nanocatalyst particles on the dolomite corepack's surface. The nanocatalysts deposited on the rock were in the range of 13 nm–1220 nm with two types, spherical- and agglomerated-shaped. The X-Ray Fluorescence Spectroscopy (XRF) was also used to determine metal content distributions along the corepack. Finally, ISUT's kinetic modeling studies so far, and this one, suggest the convenience of using the same model for the reservoirs studies, which include the effects of the conditions such as temperature, pressure or residence time used during ISUT's process application.

Field-Development Optimization of the In-Situ Upgrading Process Including the Ramp-Up Phase

Summary Field-development optimization and optimization at the pattern scale are crucial to maximize the value of thermal enhanced-oil-recovery (EOR) projects. Application of a field net-present-value (NPV)-based pattern optimization algorithm honoring field-scale surface and subsurface constraints for in-situ-upgrading (IUP) projects has been described in the recent past. In this paper, we describe the development and application of a novel field-development-optimization capability, including the optimization of the ramp-up phase to accelerate the production to achieve a faster cash flow and high surface-facility utilization. We integrate this new capability into a robust field NPV optimization platform. A two-stagefield-development optimization algorithm is developed in this work. First, the steady-state pattern is optimized using the field-scale pattern optimization algorithm while honoring field-scale constraints and using a combined surface and subsurface performance-indicator-driven objective function. Ramp-up pattern designs are optimized separately using a solely pattern-scaleperformance-driven objective function in this stage. A preliminary pattern-delay time optimization follows next to precondition the problem for the subsequent field-scale optimization stage. The ramp-up pattern and pattern-delay times are optimized using a constant steady-state pattern in the second step of the algorithm. An appropriately penalized field-NPV-based objective function is used in this step to enforce field-scale surface and subsurface constraints. Optimization results on a realistic example application indicate that the time to oil-rate plateau could be significantly reduced on the order of multiple years while honoring the surface production constraints. This requires the use of an optimized ramp-up pattern in conjunction with the optimal steady-state pattern. The ramp-up pattern is approximately two patterns wide and features an increased heater density to deliver production acceleration. It is also notably more robust against the effects of subsurface uncertainties.

Performance and important engineering aspects of air injection assisted in situ upgrading process for heavy oil recovery

In-situ upgrading (ISU) via downhole heating is an innovative and efficient technique for oil shale and ultra heavy oil recovery. However, low heat transfer in the ISU process can limit its application in large scale. Therefore, efficient air injection assisted ISU process (AAISU) was proposed. In this study, reservoir stimulation of the AAISU process was performed to investigate the effect of air injection on heat transfer, oil production performance and energy conversion efficiency, as compared to the original ISU process. The influences of important engineering aspects were investigated, including well pattern, well distance, heating temperature and air injection rate for the field application of the AAISU technique. The reservoir stimulation results indicate that heat transfer rate can be significantly accelerated by air injection, and the average reservoir temperature during the AAISU can be increased to 250 °C after one year, in comparison with that of 116 °C in the ISU process. The contribution of air injection on the total heat transfer can be approached to 60%. Air injection can also enhance oil recovery and improve the energy efficiency. Heating temperature and air injection rate also have significant impact on the performance of the AAISU process. For a 15 m × 15 m × 10 m geo-model, increase of the heating temperature from 250 °C to 350 °C and air injection rate from 500 m3/day to 1000 m3/day can result in improved energy efficiency. However, heating temperature above 350 °C and the air injection rate over 1000 m3/day can led to a decreased energy efficiency, due to higher energy consumption on electrical heating and high rate of air injection.

Experimental study on thermal cracking reactions of ultra-heavy oils during air injection assisted in-situ upgrading process

In-situ upgrading (ISU) via down-hole heating can be an effective technique for exploitation of heavy oil reservoirs. In order to increase the heat transfer rate and reservoir energy, air or gas injection assisted in-situ upgrading process (AAISU) has been proposed. In the AAISU process, and also in the traditional in-situ combustion (ISC) process, complex thermal cracking reactions of heavy oils occur along with low temperature oxidation (LTO) in the presence of air or oxygen at high pressure conditions. In comparison with the conventional oil cracking or pyrolysis in refinery (without or with less oxygen), it has been concerned that low temperature oxidation of oil components during air injection may have some impacts on their cracking reactions. In this study, thermal cracking experiments of ultra-heavy oils in small batch reactor as well as thermogravimetry analysis (TGA) experiments have been conducted under high pressure in the presence of air and nitrogen to simulate the AAISU process. The starting temperature for cracking, the products of cracking reactions, reaction rate, and the influence of temperature and pressure on reaction kinetics have been investigated in order to reveal the influence of LTO on cracking reaction and to clarify the confusions. The experimental results demonstrated that the presence of air has some kind negative effect on the cracking of oils compared with that in the presence of nitrogen. For a typical ultra-heavy oil, the minimum starting temperature for cracking is around 350 °C in the presence of air at 3.2 MPa for a reaction time of over 30 days, while the starting temperature is around 325 °C when nitrogen is present. Less light oil components produced and lower cracking reaction rate (about 20–30%) were observed when air was present in comparison with that of nitrogen at the same pressure. That means higher activation energy is required to activate the thermal cracking reaction of oils when air or LTO reactions are involved.

Air assisted in situ upgrading via underground heating for ultra heavy oil: Experimental and numerical simulation study

In situ upgrading (ISU) via underground heating and thermal cracking is regarded as an effective technique for exploiting ultra heavy oils, in which the heavy oil components can be cracked into light oils and gases for production. However, the slow heating rate via conduction from wellbore to oil formation is the main issue concerned in the conventional ISU process. Herein, an air injection assisted ISU technique (AAISU) is proposed to improve heat transfer by gas convection and along with the thermal effect of oil oxidation due to the oxygen in the injected air. Air injection can also provide extra energy for oil production and reservoir pressure maintenance. To illustrate the advantage of the proposed AAISU technique, thermal cracking experiments of ultra heavy oil samples in the presence of air under high pressure were conducted to investigate the reaction mechanisms and to establish the kinetics models of the oxidation and cracking reactions. Moreover, reservoir numerical simulation studies are performed to evaluate the effects of air injection during the ISU process. The experiment results indicate that the ultra heavy oil can be effectively cracked into gases, light oils and coke-like substances in the presence of air at temperature over 350 °C. The activation energy of the thermal cracking derived is around 248 kJ/mol. The numerical simulation results show that the heat transfer rate can be effectively enhanced by air injection because of the heat convection of the air flow and the thermal effect of the low temperature oxidation reactions of oil components. The total oil recovery factor can be increased via air injection with improved energy conversion efficiency from 6.51 GJ/GJ to 8.42 GJ/GJ.

In-Situ Upgrading Process Offers Potential for Heavy-Oil Recovery

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 190695, “Simulations of In-Situ Upgrading Process: Interpretation of Laboratory Experiments and Study of Field-Scale Test,” by A. Perez-Perez, SPE, M. Mujica, and I. Bogdanov, SPE, Computational Hydrocarbon Laboratory for Optimized Energy Efficiency, and A. Brisset, SPE, and O. Garnier, SPE, Total, prepared for the 2018 SPE Improved Oil Recovery Conference, Tulsa, 14–18 April. The paper has not been peer reviewed. In-situ upgrading (IU) is a promising method of improved viscous- and heavy-oil recovery. The IU process involves a reservoir being exposed to temperatures greater than 300°C long enough to promote a series of chemical reactions. In this work, the authors developed a numerical model of IU on the basis of laboratory experiences and validated results, applying the model to an IU test published in the literature. Simulation results for the cores submitted have shown that oil production and oil-sample quality were well-predicted by the model. Introduction In this paper, results of a previously published experiment and those of an unpublished experiment (Experiment B) are modeled and discussed. To accomplish this, an in-house code is developed for coupling the kinetic model with the thermodynamic description, a process detailed in the complete paper. This code was able to represent both the reaction dynamics of bitumen-fraction decomposition and the phase distribution and production of pseudocomponents. The resulting model was used to simulate an IU field-scale test (using data from Shell’s Viking pilot). Experimental Simulation A 2D homogeneous radial model was used to simulate two IU experiments. Elemental gridblock size was 5 mm in both directions. The model size was 5×30 cells (Experiment A) and 5×138 cells (Experiment B). A total of 30 pseudocomponents was provided in the simulation model. A sensitivity analysis was performed to identify the effect of some parameters in the IU model on the basis of experimental conditions in the experiments. This analysis was focused on less-certain properties related to the core and physical properties of oil pseudocomponents. Experimental and Simulation Results. In the process of model development and adaptation, more effort has been dedicated to specify the thermodynamic model than the kinetic model. The final model is capable of successfully predicting liquid production at various test scales and conditions. To explain the mismatch observed between simulation and experimental results of solid generation during IU, the authors performed estimations of solid mass that would be generated under the IU conditions of both experiments in a closed system. The resulting amount of generated solids is the highest possible because the initial hydrocarbons were all retained inside a core. The estimated amount of pyrobitumen for Experiment A was 0.022 kg. This value is still lower than that reported for laboratory conditions (0.024 kg). With regard to Experiment B, taking into account that 35% of the original oil was evacuated by thermal expansion of fluids, the estimated mass of pyrobitumen was approximately 0.070 kg (for closed volume). This value is significantly lower than that reported by the laboratory for this experiment (0.090 kg). The most probable reason is a natural difference in the physicochemical conditions for measurements in kinetic tests and IU experiments.

In-Situ Upgrading of Organosolv Lignin- and Cellulose-Derived Pyrolyzates Over Ce-MCM-41 Catalyst.

Lignocellulosic biomass, principally consisting of cellulose, hemicellulose and lignin, is a main renewable source for the production of biofuels and valuable chemicals. For instance, the polyaromatic structure of lignin fraction of biomass makes it a high potential feedstock for the production of valuable aromatic chemicals such as phenolic compounds. In this work, selective conversion of the organosolv lignin-derived pyrolyzates to alkylphenols was carried out using Ce-MCM-41 as In-Situ catalyst. Catalytic fast pyrolysis of the organosolv lignin was carried out on a tandem micro-pyrolyzer coupled with gas chromatography and mass spectrometry (GC-MS) detectors. The refined pyrolytic vapor was mainly consisting of phenolics (phenol, alkylphenols, guaiacol and alkylguaiacols), monoaromatic hydrocarbons (benzene, toluene and xylenes), esters (formic acid ethyl ester, acetic acid methyl ester and hexadecanoic acid methyl ester), aldehydes (formaldehyde and methylbenzaldehyde), acids (hydroxyacetic acid and benzoic acids), furans (2-methylfuran and dihydrofuran) and ethanol. Our data showed that the selectivity of products was influenced by pyrolysis temperature (500, 550 and 600 °C). Maximum selectivity of alkylphenols (10.3%) was obtained at 550 °C. Besides In-Situ pyrolysis of organosolve lignin, the In-Situ upgrading of the cellulose-derived pyrolyzates was carried out using Ce-MCM-41 at 550 °C. In-Situ pyrolysis of cellulose using Ce-MCM-41 could obtain high selectivity of aldehydes (11.4%), furans (9.6%) and ketones (3.2%).

Scaling analysis of the In-Situ Upgrading of heavy oil and oil shale

The In-Situ Upgrading (ISU) of heavy oil and oil shale is investigated. We develop a mathematical model for the process and identify the full set of dimensionless numbers describing the model. We demonstrate that for a model with nf fluid components (gas and oil), ns solid components and k chemical reactions, the model was represented by 9+k×(3+nf+ns-2)+8nf+2ns dimensionless numbers. We calculated a range of values for each dimensionless numbers from a literature study. Then, we perform a sensitivity analysis using Design of Experiments (DOE) and Response Surface Methodology (RSM) to identify the primary parameters controlling the production time and energy efficiency of the process. The Damköhler numbers, quantifying the ratio of chemical reaction rate to heat conduction rate for each reaction, are found to be the most important parameters of the study. They depend mostly on the activation energy of the reactions and of the heaters temperature. The reduced reaction enthalpies are also important parameters and should be evaluated accurately. We show that for the two test cases considered in this paper, the Damköhler numbers needed to be at least 10 for the process to be efficient. We demonstrate the existence of an optimal heater temperature for the process and obtain a correlation that can be used to estimate it using the minimum of the Damköhler numbers of all reactions.

Modelling in-situ upgrading of heavy oil using operator splitting method

The in-situ upgrading (ISU) of bitumen and oil shale is a very challenging process to model numerically because of the large number of components that need to be modelled using a system of equations that are both highly non-linear and strongly coupled. Operator splitting methods are one way of potentially improving computational performance. Each numerical operator in a process is modelled separately, allowing the best solution method to be used for the given numerical operator. A significant drawback to the approach is that decoupling the governing equations introduces an additional source of numerical error, known as the splitting error. The best splitting method for modelling a given process minimises the splitting error whilst improving computational performance compared to a fully implicit approach. Although operator splitting has been widely used for the modelling of reactive-transport problems, it has not yet been applied to the modelling of ISU. One reason is that it is not clear which operator splitting technique to use. Numerous such techniques are described in the literature and each leads to a different splitting error. While this error has been extensively analysed for linear operators for a wide range of methods, the results cannot be extended to general non-linear systems. It is therefore not clear which of these techniques is most appropriate for the modelling of ISU. In this paper, we investigate the application of various operator splitting techniques to the modelling of the ISU of bitumen and oil shale. The techniques were tested on a simplified model of the physical system in which a solid or heavy liquid component is decomposed by pyrolysis into lighter liquid and gas components. The operator splitting techniques examined include the sequential split operator (SSO), the Strang-Marchuk split operator (SMSO) and the iterative split operator (ISO). They were evaluated on various test cases by considering the evolution of the discretization error as a function of the time-step size compared with the results obtained from a fully implicit simulation. We observed that the error was least for a splitting scheme where the thermal conduction was performed first, followed by the chemical reaction step and finally the heat and mass convection operator (SSO-CKA). This method was then applied to a more realistic model of the ISU of bitumen with multiple components, and we were able to obtain a speed-up of between 3 and 5.

Kinetics of the In-Situ Upgrading of Heavy Oil by Nickel Nanoparticle Catalysts and Its Effect on Cyclic-Steam-Stimulation Recovery Factor

Summary The effect of nickel nanoparticles on in-situ upgrading of heavy oil (HO) during aquathermolysis and the effect of this process on the recovery through cyclic steam injection were studied. High-temperature experiments were conducted with a benchtop reactor to study the kinetics of the reactions among oil, water, and sandstones in the presence and absence of the nickel nanoparticles. Eighteen experiments were conducted at three different temperatures and at three different lengths of time, and the evolved hydrogen sulfide during the reaction was analyzed. The kinetic analysis showed that nickel nanoparticles reduce the activation energy of the reactions corresponding to the generation of hydrogen sulfide by approximately 50%. This reaction was the breakage of C-S bonds in the organosulfur compounds of the HO. The maximal catalysis effect was observed to be at a temperature of approximately 270°C. Also, the simulated-distillation gas-chromatography (GC) analysis of the oil sample, after the aquathermolysis reactions, confirmed the catalysis effect of nickel nanoparticles. According to this analysis, by catalytic process, the concentration of the components lighter than C30 increased whereas the concentration of heavier components decreased. Next, the effect of the catalytic aquathermolysis on the recovery factor of the steam-stimulation technique was studied. The stimulation experiments consisted of three injection/soaking/production phases. The results showed that the nickel nanoparticles increased the recovery factor by approximately 22% when the nanoparticles were injected with a cationic surfactant and xanthan-gum polymer. This increase of recovery was approximately 7% more than that of the experiment conducted with the surfactant and polymer only.

In-Situ Upgrading of Heavy Oil/Bitumen During Steam Injection by Use of Metal Nanoparticles: A Study on In-Situ Catalysis and Catalyst Transportation

Summary Studies on the application of transition-metal catalysts for heavy-oil or bitumen in-situ upgrading were conducted in the absence of a porous medium, mainly measuring the characteristics of heavy oil in reaction with metal ions at static conditions with the help of a magnetic stirrer. Metal species in ionic form are not soluble in oil phase. Therefore, metal particles, as inhomogeneous catalysts, are considered in this paper. Furthermore, dynamic tests in porous media are needed to clarify the injection possibility of the metal particles and their effect on in-situ upgrading of heavy oil. Injection of metal particles may deteriorate the recovery process by damaging porous media because of attractive forces such as van der Waals and electrostatic forces between particles and porous rock. A better understanding of these forces and their importance in the retention of particles is required. In this paper, the catalysis effect of pure nanometer-sized nickel during steam-injection application was compared with that of an industrial catalyst such as micron-sized Raney nickel. The changes in the viscosity, refractive index, and asphaltene content were measured after each test to analyze the catalysis effects. Nickel nanoparticles showed a better catalysis compared with Raney nickel. The approximate optimum concentration of the catalysts was determined. Then, the catalysis effect of nickel nanoparticles was studied in the presence of sandpack as a porous medium. The results showed accelerated catalysis in presence of the sands. Also, nickel nanoparticles improved the oil recovery factor. The next phase of this paper studies the injectivity and transport of nickel particles. The injected suspension was stabilized by use of xanthan gum polymer and ultrasonication. The effect of solution pH, which controls the magnitude of the repulsive electrostatic forces, was clarified. Stabilization of the metal particles’ suspension was studied at different pH values through zeta-potential measurements. Also, the zeta potential of the recovered suspensions was studied to confirm the stability of the suspension during travel through the porous medium. Depending on the size, particles carry different charges and have different settling velocities. Therefore, the stabilization pH and dispersant concentration were different from one sample to another. The results of the injectivity tests confirmed the lower retention and better injectivity of nanoparticles in comparison with micron-sized particles.

Numerical Simulation of the In-Situ Upgrading of Oil Shale

Summary Oil shale is a highly abundant energy resource, though commercial production has yet to be realized. Thermal in-situ upgrading processes for producing hydrocarbons from oil shale have gained attention recently, however, in part because of promising results reported by Shell using its in-situ conversion process (Crawford et al. 2008). This and similar processes entail heating the oil shale to approximately 700°F (371°C), where the kerogen in the shale decomposes through a series of chemical reactions into liquid and gas products. In this paper, we present a detailed numerical formulation of the in-situ upgrading process. Our model, which can be characterized as a thermal/compositional, chemical reaction, and flow formulation, is implemented into Stanford's General Purpose Research Simulator (GPRS). The formulation includes strongly temperature-dependent kinetic reactions, fully compositional flow and transport, and a model for the introduction of heat into the formation through downhole heaters. We present detailed simulation results for representative systems. The model and heating patterns are based on information in Shell publications; chemical-reaction and thermodynamic data are from previously reported pyrolysis experiments. After a relatively modest degree of parameter adjustment (with parameters restricted to physically realistic ranges), our results for oil and gas production are in reasonable agreement with available field data. We also investigate various sensitivities and show how production is affected by heater temperature and location. The ability to model these effects will be essential for the eventual design and optimization of in-situ upgrading operations.

Benefits of Insitu Upgrading Reactions on the Integrated Operations of the Orinoco Heavy Oil Fields

Benefits of Insitu Upgrading Reactions on the Integrated Operations of the Orinoco Heavy Oil Fields