Download or read book Mass Transfer Studies in Heavy Oil Recovery Using Solvents written by Vijitha Mohan and published by . This book was released on 2017 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Heavy oil, sometimes called bitumen, is known for its high viscosity (above 100 cp) and low API gravity (below 22°). In most cases, viscosity reduction is needed for the final product. There is a considerable amount of heavy oil in Alberta, Canada and the world's largest heavy oil deposit is in Venezuela. Yet less than 1% of it can be recovered because of its high viscosity. For shallow reservoirs, it is possible to resort to open cast mining. For deeper reservoirs, steam is used at ~ 350 °C which gets the oil viscosity reduced to 1cp, which can now be drained out. This process requires large amount of water to make steam, the used water cannot be reused due to presence of high levels of bitumen in it and is currently leading to pollution. The recovered bitumen being highly viscous needs a diluent like naphtha for transportation. Therefore another method is devised which involves using gaseous or liquid solvents directly to bring down the viscosity of bitumen. One such method, vapor extraction (VAPEX) process uses gaseous solvents like hydrocarbon solvents and CO2 to reduce bitumen viscosity. Vaporized solvents is introduced laterally to bitumen to reduce its viscosity and the less viscous bitumen drains under gravity. Solubility of solvents in bitumen is analyzed first. As solvents solubilize, it diffuses into bitumen and the diffusivity is strongly concentration dependent. The concentration dependence of solvent diffusivity in bitumen is measured next. Knowing the solubility and diffusivity of solvents, a model is used next to simulate oil recovery. It predicts an optimum solvent for this oil recovery process"--Abstract, page iv.

Download or read book Mass Transfer Mechanisms During the Solvent Recovery of Heavy Oil written by Lesley Anne James and published by . This book was released on 2009 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Canada has the second largest proven oil reserves next to Saudi Arabia which is mostly located in Alberta and Saskatchewan but is unconventional heavy oil and bitumen. The tar sands are found at the surface and are mined, yet 80% of the 173 billion barrels of heavy oil and bitumen exist in-situ according to the Canadian Association of Petroleum Producers (CAPP). Two factors inhibit the economic extraction and processing of Canadian heavy oil; its enormous viscosity ranging from 1000 to over 1 million mPa.s and the asphaltene content (high molecular weight molecules containing heavy metals and sulphur). Heavy oil and bitumen were only included in the reserves estimates through the efforts of Canadian enhanced oil recovery (EOR) research. Viscosity reduction is the one common element of in-situ methods of heavy oil recovery with the exception of cold production. Currently, steam assisted gravity drainage (SAGD) and cyclic steam stimulation (CSS) are being used commercially in the field where the oil's viscosity is reduced by injecting steam. Thermal methods are energy intensive requiring vast volumes of water such that any improvement would be beneficial. Solvent extraction is one alternative requiring no water, the solvent is recoverable and reusable, and depending on the mode of operation the heavy oil is upgraded in-situ. Vapour Extraction (VAPEX) and enhanced solvent extraction (N-SolvTM) are two such methods. VAPEX and N-Solv reduce the bitumen's viscosity via mass transfer and a combination of mass and heat transfer, respectively. A light hydrocarbon solvent (instead of steam) is injected into an upper horizontal well where the solvent mixes with the heavy oil, reduces its viscosity and allows the oil to drain under gravity to a bottom production well. The idea of using solvents for heavy oil extraction has been around since the 1970s and both VAPEX and N-Solv are patented processes. However, there is still much to be learned about how these processes physically work. Research to date has focused on varying system parameters (including model dimensions, permeability, heavy oil viscosity, solvent type and injection rate, etc.) to observe the effect on oil production from laboratory scale models. Based on an early mass balance model by Butler and Mokrys (1989) and an improvement by Das (1995), molecular diffusion alone cannot account for the produced oil rates observed from laboratory models. Until recently, very little progress had been made towards qualifying and quantifying the mass transfer mechanisms with the exception of the diffusivity of light hydrocarbons in heavy oil. Mass transfer can only be by diffusion and convection. Differentiating and quantifying the contribution of each is complex due to the nature and viscosity of the oil. The goal of this thesis is to investigate the mass transfer mechanisms during the solvent recovery of heavy oil.

Download or read book Phase Behaviour and Mass Transfer of Solvent s CO2 heavy Oil Systems Under Reservoir Conditions written by Huazhou Li and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Enhanced Heat and Mass Transfer for Alkane Solvent s CO2 Heavy Oil Systems at High Pressures and Elevated Temperatures written by Sixu Zheng and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The tremendous heavy oil reserves have recently attracted considerable attention for sustaining the increasing global oil consumption. Heavy oil reservoirs are characterized by high oil viscosity and drastic drop of reservoir pressure in a short period during production, imposing great challenges to recover such heavy oil resources. In practice, conventional steam-based thermal recovery techniques are generally ineffective or uneconomical in thin heavy oil reservoirs due to operational and environmental constraints. Since CO2 is a highly soluble, low cost, and environment-friendly injectant, hot CO2 injection is alternatively considered to be a promising technique for enhancing heavy oil recovery from these thin reservoirs. Not only does it take advantages of both thermal energy and dissolution of solvents to recover heavy oil resources, but also it contributes to the alleviation of carbon footprint. Compared with the CO2-alone processes, addition of alkane solvents to the CO2 stream leads to enhanced viscosity reduction and swelling effect of heavy oil. Thus, it is of fundamental and practical importance to study the underlying mechanisms of hot alkane solvent(s)-CO2 processes for enhancing heavy oil recovery at high pressures and elevated temperatures. In order to more accurately determine the equilibrium phase properties for alkane solvent(s)-CO2-heavy oil systems with the Peng-Robinson equation of state (PR EOS), heavy oil is characterized as multiple pseudocomponents, while a volume translation strategy is employed to improve its prediction performance. The binary interaction parameter (BIP) correlations are tuned with the experimentally measured saturation pressures for the same heavy oil. Such volume-translated PR EOS with a modified alpha function incorporating the tuned BIP correlations is capable of accurately predicting the saturation pressures and swelling factors of the aforementioned systems. The alkane solvent-CO2-heavy oil pressure decay systems under a constant temperature have been theoretically modelled to not only examine the effect of adding alkane solvents into CO2 stream, but also determine both apparent diffusion coefficient of a gas mixture and individual diffusion coefficient of each component in heavy oil. It is found that alkane solvents (i.e., C3H8 and n-C4H10) diffuse much faster than CO2 in heavy oil at reservoir temperature. Compared to pure CO2, addition of C3H8 into the CO2 stream tends to accelerate the swelling of heavy oil under similar conditions. Experimental and theoretical techniques have also been developed to couple heat and mass transfer for hot CO2-heavy oil systems with and without addition of alkane solvents. Both molecular diffusion coefficient of each component and apparent diffusion coefficients of alkane solvent(s)-CO2 mixtures are determined once the discrepancy between the measured and calculated dynamic swelling factors has been minimized. The thermal equilibrium is found to achieve in a much shorter time than mass equilibrium. CO2 diffusion coefficient in heavy oil increases with temperature at a given pressure. Compared with hot CO2 injection, addition of C3H8 into hot CO2 stream contributes to an enhanced swelling effect of heavy oil. A higher concentration of C3H8 in the CO2-C3H8 mixture tends to accelerate gas diffusion and thus induce a stronger oil swelling. Among the n-C4H10-heavy oil system, n-C4H10-CO2-heavy oil system, and C3H8-n-C4H10-CO2- heavy oil system, smaller dynamic swelling factors are obtained for the n-C4H10-heavy oil system, while the largest dynamic swelling factor of 1.118 at the end of diffusion test is achieved for the C3H8-n-C4H10-CO2-heavy oil system.

Download or read book Nonequilibrium Phase Behaviour and Mass Transfer of Alkane Solvents s CO2 Heavy Oil Systems Under Reservoir Conditions written by Yu Shi and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: During primary heavy oil recovery, a unique phenomenon has been found to be closely associated with an unexpected high recovery factor, a remarkably low gas-oil ratio, and a higher-than-expected well production rate due mainly to the foamy nature of viscous oil containing gas bubbles. Even for secondary and tertiary recovery techniques, it is possible to artificially induce foamy oil flow in heavy oil reservoirs by dissolution with injected gases (e.g., CO2 and alkane solvents), which is characterized by time-dependent (i.e., nonequilibrium) phase behaviour. The entrained gas bubbles in the heavy oil are considered as the main mechanism accounting for such distinct phase behaviour. Therefore, it is of fundamental and practical importance to quantify the nonequilibrium phase behaviour and mass transfer of alkane solvent(s)-CO2-heavy oil systems under reservoir conditions. A novel and pragmatic technique has been firstly developed and validated to accurately quantify the preferential diffusion of each component in alkane solvent(s)- assisted recovery processes with consideration of natural convection induced by the heated and diluted heavy oil. The Peng-Robinson equation of state, heat transfer equation, and diffusion-convection equation are coupled to describe both mass and heat transfer for the aforementioned systems. The individual diffusion coefficient between each component of a gas mixture and liquid phase is respectively determined once either the deviation between the experimentally measured and theoretically calculated mole fraction of CO2/solvents or the deviation between the experimentally measured dynamic swelling factors and the theoretically calculated ones has been minimized. ii A robust and pragmatic technique has also been developed to quantify nonequilibrium phase behaviour of alkane solvent(s)-CO2-heavy oil systems at a constant volume expansion rate and a constant pressure decline rate, respectively. Experimentally, constant-composition expansion (CCE) tests have been conducted for alkane solvent(s)-CO2-heavy oil systems with a PVT setup, during which not only pressure and volume are simultaneously monitored and measured, but also gas samples were respectively collected at the beginning and the end of experiments to perform compositional analysis. Theoretically, mathematical formulations have been developed to quantify the amount of the evolved gas as a function of time, while mathematical models for compressibility and density of the oleic phase mixed with the entrained gas (i.e., foamy oil) are respectively formulated. In addition to a mechanistic model for quantifying a single gas bubble growth, a novel and pragmatic technique has been proposed and validated to quantify dynamic volume of foamy oil for the aforementioned systems under nonequilibrium conditions by taking preferential mass transfer of each component in a gas mixture into account. The individual diffusion coefficient of each gas component with consideration of natural convection is found to be larger than that obtained with conventional methods. An increase in either volume expansion rate or pressure decline rate would increase the critical supersaturation pressure, whereas a high temperature leads to a low critical supersaturation pressure. When pressure is below the pseudo-bubblepoint pressure, density and compressibility of foamy oil are found to sharply decrease and increase at the pseudo-bubblepoint pressure, respectively. Also, pseudo-bubblepoint pressure and rate of gas exsolution is found to be two mechanisms dominating the volume-growth rate of the evolved gas, which is directly proportional to supersaturation pressure, pressure decline rate, and concentration of each gas component under nonequilibrium conditions.

Download or read book Effects of Waterflooding Solvent Injection and Solvent Convective Dispersion on Vapour Extraction VAPEX Heavy Oil Recovery written by Mohammad Derakshanfar and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dynamic and Static CO2 Mass Transfer Processes in Bulk Heavy Oil and Heavy Oil Saturated Porous Media written by Ali Kavousi and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mass Transfer of Alkane Solvents CO2 Heavy Oil Systems in the Absence and Presence of Porous Media Under Reservoir Conditions written by Hyun Woong Jang and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: For a thin heavy oil reservoir where thermal methods are not applicable due to heat loss to over- and under-burdens, gas injection is considered to be an effective alternative. One of the major mechanisms associated with gas injection is the molecular diffusion of dissolved gas(es) which reduce the viscosity of heavy oil while inducing oil swelling. Physically, addition of a less volatile gas to a more volatile gas enhances both viscosity reduction and oil swelling, while the presence of porous media complicates such mass transfer processes. Diffusivity of dissolved gas(es) in heavy oil is often estimated as a constant, while limited attempts have been made to determine it as a function of concentration in the absence and presence of porous media. In this study, a power-law mixing rule is firstly developed to correlate apparent diffusivity of a binary gas mixture in heavy oil with the diffusivity of each pure gas based on the principle of corresponding states. Comparison of the correlated results with the measured data from literature proves that the correlation can be used to accurately predict the apparent diffusivities of binary gas mixtures. To verify the effect of a gas component on the other in a binary gas mixture diffusing in heavy oil, the cross-term diffusivities are estimated for a CO2-C3H8 mixture as well as its main-term diffusivities using the experimental data from Li et al. (2017b). It is found that the existence of a gas with a high concentration at the gas-heavy oil interface enhances the mass transfer of the other gas component through the cross-term diffusivity by generating a high concentration gradient. Then, a generalized methodology has been developed to determine the diffusivity of a gas (e.g., CO2) in a heavy oil as an exponential function of gas concentration with consideration of oil swelling applying the test data from Li et al. (2017b) and Li and Yang (2016). The obtained concentration-dependent diffusivity of CO2 is reasonable and accurate as well as it can be converted for use at different pressures and temperatures. Further, a robust and pragmatic technique has been developed for the first time to implicitly evaluate the concentration-dependency of diffusivity for each component in a binary gas mixture diffusing in heavy oil as a power function of oil viscosity. As for the C3H8/CO2-heavy oil systems, the dependency of C3H8 diffusivity on the gas concentration is significantly higher than that of CO2 diffusivity. Lastly, the conventional pressure decay technique has been improved and extended to determine the effective diffusivity of either a pure gas or each component in a binary gas mixture in an unconsolidated porous medium saturated with heavy oil. Effective diffusivities are determined by matching the measured gas compositions in liquid-phase at the end of pressure decay tests with the calculated ones. Such determined effective diffusivity of C3H8 is found to be larger than that of CO2, which is in accordance with previous studies performed for the same gases diffusing in the same bulk heavy oil, although the porous medium hinders the mass transfer of gas(es).

Download or read book Sustainable In Situ Heavy Oil and Bitumen Recovery written by Mohammadali Ahmadi and published by Elsevier. This book was released on 2023-03-24 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sustainable In-Situ Heavy Oil and Bitumen Recovery: Techniques, Case Studies, and Environmental Considerations delivers a critical reference for today’s energy engineers who want to gain an accurate understanding of anticipated GHG emissions in heavy oil recovery. Structured to break down every method with introductions, case studies, technical limitations and summaries, this reference gives engineers a look at the latest hybrid approaches needed to tackle heavy oil recoveries while calculating carbon footprints. Starting from basic definitions and rounding out with future challenges, this book will help energy engineers collectively evolve heavy oil recovery with sustainability applications in mind. Explains environmental footprint considerations within each recovery method Includes the latest hybrid methods such as Hybrid of Air-CO2N2 and Cyclic Steam Stimulation (CSS) Bridges practical knowledge through case studies, summaries and remaining technical challenges

Download or read book Enhanced Solvent Vapour Extraction Processes in Thin Heavy Oil Reservoirs written by Xinfeng Jia and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Interplay of Capillarity Drainage Height and Aqueous Phase Saturation on Mass Transfer Phenomena in Heavy Oil Recovery by Vapex Process written by Farid Ahmadloo and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1977 with total page 646 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Phase Behaviour of Solvent s Water Heavy Oil Systems at High Pressures and Elevated Temperatures Based on Isenthalpic Flash written by Desheng Huang and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The hybrid steam-solvent injection processes have been proved to be a promising technique for enhancing heavy oil recovery as they combine the advantages from both heat transfer of steam and mass transfer of solvent(s) to further reduce the viscosity of heavy oil. Multiphase isenthalpic flash calculation is required in compositional simulations of the aforementioned processes, which involve vapour, oleic, and aqueous three-phases since water is inevitably associated with steam injection processes. As such, it is of fundamental and pragmatic importance to accurately quantify the phase behaviour of solvent(s)/water/heavy oil systems at high pressures and elevated temperatures by use of isenthalpic flash algorithms. A modified correlation and a new enthalpy determination algorithm have been developed to more accurately predict ideal gas heat capacities and enthalpies for normal alkanes/alkenes and hydrocarbon fractions, respectively. By assuming that only the presence of water and solvents with high solubilities in water is considered in the aqueous phase, a robust and pragmatic water-associated isenthalpic flash (WAIF) model has been developed to perform multiphase isenthalpic flash calculations for solvent(s)/water/heavy oil mixtures at high pressures and elevated temperatures. The new isenthalpic flash model developed in this work can handle multiphase equilibria flash calculations at high pressures and elevated temperatures. Subsequently, phase boundaries of C3H8/CO2/water/heavy oil mixtures in both the pressure-temperature (P-T) and enthalpy-temperature (H-T) phase diagrams have been determined, respectively. Experimentally, the phase boundary pressures are determined for three C3H8/CO2/water/heavy oil mixtures by using a conventional pressurevolume- temperature (PVT) setup in the P-T phase diagram. Theoretically, the previously developed WAIF model and the new isenthalpic determination algorithm together with the new alpha functions for water and non-water components are applied as the thermodynamic model to reproduce the multiphase boundaries of the aforementioned systems. The water-associated model is able to provide a good prediction of the experimental measurement in terms of phase boundaries and phase compositions. In addition, a new algorithm is developed to determine vapour/liquid/ liquid (VL1L2) phase boundaries of alkane solvent(s)/CO2/heavy oil mixtures. A new thermodynamic model based on the modified Peng-Robinson equation of state (PR EOS) together with the Huron-Vidal mixing rule is developed to experimentally and theoretically quantify the phase behaviour of dimethyl ether (DME)/water/heavy oil mixtures which include polar components. The new model is capable of accurately reproducing the experimentally measured multiphase P-T and H-T boundaries, phase volumes, and swelling factors, while it can also be used to determine DME partition coefficients and DME solubility.

Download or read book Solvents and Explosives to Recover Heavy Oil written by Larman J. Heath and published by . This book was released on 1972 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration. Technical Information Center and published by . This book was released on 1977 with total page 982 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 1052 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.

Download or read book Aqueous Solution of Ketone Solvent for Enhanced Oil Recovery in Tight Reservoirs written by Mingyuan Wang and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Horizontal drilling and multi-stage hydraulic fracturing have made it possible to recover oil from tight formations at economically feasible production rates. However, tight oil reservoirs often show a rapid decline in the production rate. Primary recovery factors in tight reservoirs are typically smaller than 10%. There is a critical need for enhanced oil recovery in tight reservoirs. Most tight oil reservoirs are originally intermediate- to oil-wet. Wettability alteration agents have been studied to facilitate water imbibition into tight rock matrices to enhance oil recovery. However, many factors affect the efficacy and efficiency of enhanced oil recovery by wettability alteration agents. The conventional wettability modifiers, such as surfactants, decrease the interfacial tension between the aqueous and oleic phases, which tends to limit the imbibition rate. The performance of wettability modifiers also depends on their mass transfer from the fracture to the matrix. However, the mass transfer of components between the fracture and the matrix has not been studied quantitatively in the literature. In addition, initial water saturation in the matrix, the concentration of wettability modifier in the injection fluid, and the injection/production pressures also affect the efficacy and efficiency of enhanced oil recovery by wettability alteration agents. This research aims to identify a practical solvent that can alter rock wettability without affecting interfacial tension and transfer efficiently from fracture to matrix. In addition, the effect of initial water saturation on enhanced water imbibition and the impact of the chemical concentration of the injected aqueous solution is investigated. In this research, we identified 3-pentanone, a symmetric dialkyl ketone, can act as a wettability alteration agent without affecting the interfacial tension between the aqueous and oleic phases. It is conceivable that the wettability change caused by 3-pentanone is related to the polar-polar interaction between 3-pentanone molecules and the calcite surface. This interaction may reduce the polar-polar interaction of the carboxylate group of naphthenic acids in oil with the calcite surface. Next, we compared 3-pentanone with a common wettability modifier, a surfactant. The dynamic imbibition experiments demonstrated that 3-pentanone was more efficient in transferring from a fracture to the surrounding matrices than the surfactant. Results indicated that an optimal process with a wettability modifier would have a large imbibed fraction to rapidly enhance the oil displacement by brine in the matrix. Then, we demonstrated that the 3-pentanone solution increased the oil recovery from the shale matrix in comparison to the injection brine through huff-n-puff experiments. Last, we developed a new method for reliable determination of saturation pressure from constant-mass expansion data even when the total compressibility of the fluid does not show a detectable change near the saturation pressure. The new method has been used successfully to design the live-oil experiments in this and other research projects