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 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 The Vapor Extraction VAPEX Process in Fractured Heavy Oil Systems written by Reza Azin and published by LAP Lambert Academic Publishing. This book was released on 2012 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Vapor Extraction (VAPEX) has been studied theoretically and experimentally. In the first part of this work, the VAPEX process was simulated using a compositional simulator on conventional and fractured systems. Different patterns of solvent flow in fractured model comparing to the conventional model, solvent spread through fractures matrix, formation of solvent chamber, and oil recovery factor under different solvent injection schemes, effects of diffusion and fracture spacing on the process were studied and discussed. A significant finding for the application of the VAPEX process in fractured reservoirs was that fractures of poor connectivity improve the effectiveness of VAPEX process. In the second part of this work, the VAPEX process was studied experimentally using a rectangular physical model. Propane ( pure and mixed with methane) was used as solvent in all experiments. It was found that heavy oil recovery is improved as the approach pressure, defined as the saturation pressure minus operating pressure, decreases regardless of solvent composition or operating pressure. These results provide a better insight into field scale implementation of the VAPEX process.

Download or read book An Improved Vapour Solvent Injection Technique for Enhanced Heavy Oil Recovery written by Tao Jiang 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 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 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 Experimental Investigations in Improving the Vapex Performance for Recovery of Heavy Oil and Bitumen written by Nima Rezaei and published by . This book was released on 2010 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: The process of vapor extraction (VAPEX) is a recovery process which targets the heavy oil and bitumen resources. Owing to high viscosity values for these unconventional types of oil, the recovery processes in such reserves are still challenging. The unconventional oil recovery processes usually include a mechanism for reducing the oil viscosity by means of heat, solvent, or both. The process of VAPEX utilizes the injection of a light hydrocarbon solvent into a reservoir for recovering the viscous oil in place by diffusing into the oil and by providing sufficient mobility to the oil upon dilution. Although this process offers a variety of advantages over the alternative thermal recovery processes such as SAGD or CSS, it suffers from two major drawbacks. First, the oil production rates obtained in the VAPEX process are considerably lower than those obtained in the thermal processes. Second, the solvent cost is considerably high. We tried to tackle these two problems during this research and we searched for potentials for an improved VAPEX process. Three potentially improved occurrences of a VAPEX project were found when: 1) the injected solvent was superheated, 2) the wettability of media was altered to oil-wet, and 3) the vugs were distributed in the porous media. Warm VAPEX process is introduced in which the VAPEX process is thermally augmented through superheating the solvent vapor. An attractive feature of this process is the capability of the solvent in being able to condense at the bitumen-solvent interface, which provides the opportunity for the bitumen to be upgraded in-situ through asphaltene precipitation. The asphaltene precipitation was not observed during the conventional vapor extraction process and was only observed during the warm VAPEX process. Upon a moderate level of superheating, the production rate of bitumen was sufficiently improved while the solvent content of the produced oil was significantly decreased as a result of decreased solubility of solvent in the oil at elevated temperatures. Therefore, more oil was produced at lower costs. The warm VAPEX experiments were conducted at 4 temperature levels in high and low permeability media using Cold Lake bitumen and Lloydminster heavy oil blend, n-pentane was used as solvent. The warm VAPEX process was found to be more effective for Cold Lake bitumen and for less permeable media. The potential of in-situ upgrading decreased when the level of superheating increased. The second potential for an improved VAPEX process obtained when the wettability of porous medium was altered to oil-wet conditions. Although this wettability condition is harmful to steam-based recovery processes, such as SAGD, it becomes beneficial to VAPEX. For the application of VAPEX process in fractionally wet media the wettability of glass beads was altered to oil-wet conditions through silylation process, and the VAPEX experiments were conducted in a random packing of water-wet and oil-wet beads of similar size at 7 different compositions. A substantial increase in the oil production rate was observed in a completely oil-wet medium, compared to the water-wet medium. By increasing the fraction of oil-wet beads in the packing up to a critical composition, the production rate of live oil increased linearly with the increase in the fraction of oil-wet beads in the packing during the vapor extraction process. Beyond this critical composition, however, the production rate of live oil did not change significantly with further increase in the fraction of the oil-wet beads in the randomly packed medium. Vugs were also found to be beneficial to the production performance of the VAPEX process. The presence of vugs was investigated in synthesized vugular media at 4 different levels of vuggy-to-total pore volume ratios. The performance of vugular media was compared to that of the homogeneous sintered media. The vugs facilitated the production of oil during the VAPEX process by providing flow communication between the vugs and the surrounding matrix, and therefore, by providing a local high permeability pathways towards the production well. A peak in the oil production rate was observed whenever a series of vugs were simultaneously invaded by the solvent vapor. The overall production rate of oil was higher in vuggy media compared to a homogeneous media at the same overall porosity and permeability. Furthermore, the magnitude of residual oil saturation left behind was also slightly lower in vuggy medium because the vugs were perfectly drained. Finally, a constant rate air injection (CRAI) porosimetry method was developed for characterization of vugs in a vugular media. This method was successfully tested in different synthetic vugular media, and the results illustrated higher accuracy in CRAI porosimetry method compared to constant rate mercury porosimetry. CRAI porosimetry method was also employed for identification of higher permeability regions embedded in a matrix of lower permeability. The analysis of a typical porosimetry signal was also modified.

Download or read book Asphaltene Precipitation and Its Effects on a Solvent based Heavy Oil Recovery Process written by Peng Luo and published by . This book was released on 2009 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: During a solvent-based heavy oil recovery process, such as vapour extraction (VAPEX), asphaltene precipitation occurs after a sufficient amount of solvent is dissolved into a heavy oil under certain reservoir conditions. Thus, such an in-situ deasphalted heavy oil has rather different physicochemical properties from those of the original heavy crude oil in the reservoir. In particular, it is much less viscous so that the heavy oil recovery is significantly enhanced.

Download or read book Coupling of Hydrocarbon Solvents of Hot Water for Enhanced Heavy Oil Recovery written by Weiguo Luo 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 Experimental Theoretical and Numerical Studies of Solvent Based Heavy Oil Recovery Processes written by Lixing Lin 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 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 Experimental Numerical and Soft Computing Based Analysis of the Vapex Process in Heavy Oil Systems written by Mehdi Mohammadpoor 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 Theoretical and Physical Modeling of Vapour Extraction Heavy Oil Recovery written by Samane Moghadam and published by . This book was released on 2007 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theoretically, a mathematical model is formulated to predict the accumulative heavy oil production data at different times. In this model, it is assumed that the transition zone between the solvent chamber and the untouched heavy oil zone has two straight-line boundaries with a constant thickness during the VAPEX process. The constant transition-zone thickness is used as an adjustable parameter and thus determined by finding the best fit of the theoretically predicted accumulative heavy oil production data to the experimentally measured data. It is found that variations of the transition-zone thicknesses determined by using the accumulative heavy oil production data at different times are relatively small for the conducted VAPEX tests. This fact indicates that the constant transition-zone thickness assumption is reasonable. In addition, it is also found that in general, the transition-zone thickness is increased when the permeability of the VAPEX physical model is decreased.

Download or read book THE RECOVERY OF VOLATILE SOLVENTS written by CLARK SHOVE ROBINSON and published by . This book was released on 1922 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Study on Improving the Waterflooding Potential in Different Heavy Oil Solvent Systems written by Xiaolong Peng and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the unfavourable mobility ratio of heavy oil and water, waterflooding cannot be used successfully without the support of natural energies (such as solution gas drive, foamy oil effect, expansion effect, etc.) in heavy oil reservoirs. In previous studies, the parameters related to the pressure change, such as the injection rate, the start time of waterflooding, the voidage replacement ratio (VRR) control, etc., have been studied to take full advantage of the nature energies in heavy oil waterflooding processes. However, few researchers have directly studied the pressure control strategies to improve the waterflooding potential in heavy oil reservoirs. Meanwhile, previous studies investigated the heavy oil waterflooding mainly in heavy oil-methane systems or heavy oil-mixed solvent (methane and CO2) systems. Heavy oil-mixed solvent (methane and propane) systems, which often existed during cyclic solvent injection (CSI) processes, are rarely examined in heavy oil waterflooding processes. Therefore, it is of importance to study pressure control strategies to improve the waterflooding potential in different heavy oil-solvent systems. Two different heavy oil-solvent systems are included in this study: (1) a heavy oil-methane system and (2) a heavy oil-mixed solvent (methane and propane) system. For the heavy oil-methane system, four pressure control patterns are firstly investigated to screen out the optimal waterflooding pattern. Secondly, effects of pressure depletion rate are studied in the selected pressure control pattern to get the optimal control strategy. Finally, a history match is conducted for a test to further understand the heavy oil waterflooding process. For the heavy oil-mixed solvent system, one pure pressure depletion test and two waterflooding tests are carried out to understand the production behaviors in this system. For experimental study in heavy oil-solvent systems, it is found that the primary-plus waterflooding, an operational pattern that conduct the waterflooding and pressure depletion simultaneously, is the optimal pressure control pattern for heavy oil waterflooding processes. However, the pressure depletion rate in that pattern should be set properly in order to make full use of natural energies and water drive energy for both heavy oil-solvent systems. In this study, it is also understood that the interactive effect between water drive and foamy oil effect/solution gas drive at different waterflooding stages. Moreover, the optimal VRRs for different production objectives are recommended for heavy oil-methane system. For the numerical study, the results indicate that the theoretical methods can be used to provide an initial relative permeability curves for heavy oil waterflooding processes. However, due to the foamy oil effect and solution gas drive, the gas production in the heavy oil waterflooding is difficult to be matched well even by tuning the relative permeability curves. Therefore, it is suggested to consider the foamy oil module into the simulation model to get a better history match.

Download or read book Simulation of Heavy oil Recovery by Vaporized Solvent Extraction written by Viera Oballa and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Novel Solvent Injection and Conformance Control Technologies for Fractured Viscous Oil Reservoirs written by Kelli Margaret Rankin and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fractured viscous oil resources hold great potential for continued oil production growth globally. However, many of these resources are not accessible with current commercial technologies using steam injection which limits operations to high temperatures. Several steam-solvent processes have been proposed to decrease steam usage, but they still require operating temperatures too high for many projects. There is a need for a low temperature injection strategy alternative for viscous oil production. This dissertation discusses scoping experimental work for a low temperature solvent injection strategy targeting fractured systems. The strategy combines three production mechanisms -- gas-oil gravity drainage, liquid extraction, and film gravity drainage. During the initial heating period when the injected solvent is in the liquid phase, liquid extraction occurs. When the solvent is in the vapor phase, solvent-enhanced film gravity drainage occurs. A preliminary simulation of the experiments was developed to study the impact of parameter uncertainty on the model performance. Additional work on reducing uncertainty for key parameters controlling the two solvent production mechanisms will be necessary. In a natural fracture network, the solvent would not be injected uniformly throughout the reservoir. Preferential injection into the higher conductivity fracture areas would result in early breakthrough leaving unswept areas of high oil saturation. Conformance control would be necessary to divert subsequent solvent injection into the unswept zones. A variety of techniques, including polymer and silica gel treatments, have been designed to block flow through the swept zones, but all involve initiating gelation prior to injection. This dissertation also looks at a strategy that uses the salinity gradient between the injected silica nanoparticle dispersion and the in-situ formation water to trigger gelation. First, the equilibrium phase behavior of silica dispersions as a function of sodium chloride and nanoparticle concentration and temperature was determined. The dispersions exhibited three phases -- a clear, stable dispersion; gel; and a viscous, unstable dispersion. The gelation time was found to decrease exponentially as a function of silica concentration, salinity, and temperature. During core flood tests under matrix and fracture injection, the in-situ formed gels were shown to provide sufficient conductivity reduction even at low nanoparticle concentration.