Showing papers in "Petroleum Science and Technology in 2007"
TL;DR: Microbial enhanced oil recovery (MEOR) as mentioned in this paper represents the use of microorganisms to extract the remaining oil from reservoirs, which has the potential to be cost-efficient in the extraction of oil remained trapped in capillary pores of the formation rock or in areas not swept by the classical or modern enhanced OOR methods, such as combustion, steams, miscible displacement, caustic surfactant-polymers flooding, etc.
Abstract: Microbial enhanced oil recovery (MEOR) represents the use of microorganisms to extract the remaining oil from reservoirs. This technique has the potential to be cost-efficient in the extraction of oil remained trapped in capillary pores of the formation rock or in areas not swept by the classical or modern enhanced oil recovery (EOR) methods, such as combustion, steams, miscible displacement, caustic surfactant-polymers flooding, etc. Thus, MEOR was developed as an alternative method for the secondary and tertiary extraction of oil from reservoirs, since after the petroleum crises in 1973, the EOR methods became less profitable. Starting even from the pioneering stage of MEOR (1950s) studies were run on three broad areas, namely, injection, dispersion, and propagation of microorganisms in petroleum reservoirs; selective degradation of oil components to improve flow characteristics; and metabolites production by microorganisms and their effects.
287 citations
TL;DR: In this article, the mass transfer of CO2 into water and aqueous solutions of sodium dodecyl sulphate (SDS) is experimentally studied using a pressure, volume, temperature (PVT) cell at different initial pressures and a constant temperature (T = 25°C).
Abstract: The mass transfer of CO2 into water and aqueous solutions of sodium dodecyl sulphate (SDS) is experimentally studied using a pressure, volume, temperature (PVT) cell at different initial pressures and a constant temperature (T = 25°C). It is observed that the transfer rate is initially much larger than expected from a diffusion process alone. The model equations describing the experiments are based on Fick's Law and Henry's Law. The experiments are interpreted in terms of two effective diffusion coefficients—one for the early-stages of the experiments and the other one for the later stages. The results show that at the early stages, the effective diffusion coefficients are one order of magnitude larger than the molecular diffusivity of CO2 in water. Nevertheless, in the later stages the extracted diffusion coefficients are close to literature values. It is asserted that at the early stages, density-driven natural convection enhances the mass transfer. A similar mass transfer enhancement was obser...
91 citations
TL;DR: In this paper, the authors used size exclusion chromatography with 1-methyl-2-pyrrolidinone (NMP) as eluent, combined with mass spectrometry and fluorescence spectroscopy to determine the molecular mass of petroleum asphaltenes.
Abstract: The molecular weight of petroleum asphaltenes remains the subject of debate. Our previous work using size exclusion chromatography with 1-methyl-2-pyrrolidinone (NMP) as eluent, combined with mass spectrometry and fluorescence spectroscopy has indicated molecular masses up to 40,000 u. The present work investigates the asphaltene fraction of Kuwaiti crude oil. The asphaltene was separated into several NMP-soluble fractions and an insoluble residue. The evidence from size exclusion chromatography (SEC) and UV-fluorescence spectroscopy (UV-F) shows that the molecular size range and the size of the aromatic chromophores increased with increasing insolubility in NMP. A steady increase in the sizes of the range of chromophores was shown by UV-fluorescence in going from the maltene fraction, via the asphaltene sample to the NMP-insoluble residue, using chloroform as solvent. Laser-desorption mass spectra showed very wide mass ranges for the whole asphaltene and the NMP-insoluble residue of asphaltenes,...
42 citations
TL;DR: In this article, the authors illustrate the importance of measuring composition profiles within liquids as a function of time, as a basis for mutual diffusion coefficient c. The authors also propose a method to measure composition profiles of liquid mixtures of bitumen + carbon dioxide.
Abstract: Liquid-phase mutual diffusion coefficients are a key parameter in reservoir simulation models related to both primary production and envisioned secondary recovery processes for heavy oil and bitumen. The measurement of liquid-phase mutual diffusion coefficients in bitumen and heavy oil + light hydrocarbon or gas mixtures present numerous experimental and data analysis challenges due to the viscosity and opacity of the mixtures, the variability of density, viscosity and mutual diffusion coefficient with composition, and the multi-phase nature of these mixtures. Data analysis challenges are particularly acute. For example, recently reported mutual diffusion coefficient values for liquid mixtures of bitumen + carbon dioxide vary over three orders of magnitude when different analysis methods are applied to the same experimental data. In this contribution, we illustrate the importance of measuring composition profiles within liquids as a function of time, as a basis for mutual diffusion coefficient c...
41 citations
TL;DR: In this paper, the extent of similarity between the properties and composition of various types of asphalt obtained from different sources has been carefully explored, showing how ductility, penetration, and softening point are related to the chemical nature of paving asphalts in the range 41-58 softening points.
Abstract: The simplest general compositional model considers asphalt to be made up of asphaltenes, heavy oils, and resins. In the present study the extent of similarity between the properties and composition of various types of asphalt obtained from different sources has been carefully explored. It shows how ductility, penetration, and softening point are related to the chemical nature of paving asphalts in the range 41–58 softening points. Asphalt properties are found to be a direct function of its chemical constituents. The relationship between softening point and asphaltene content was found to be linear while asphalts of the same softening point are easily distinguished by the content of the resins. Evaluation of the two asphalt indices—the asphaltene index (I A ) and the Gaestel index (I C ), reveals that they both vary linearly with the composition of asphaltenes and resins thus confirming their suitability in the characterization of asphalts. Comparison of the two indices shows that IC is more suita...
38 citations
TL;DR: In this paper, the effect of various solvents on average molecular structure of asphaltenes and insolubles was studied using nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared (FTIR), and size exclusion chromatography (SEC).
Abstract: Asphaltenes and insoluble fractions of vacuum residues (VRs) of two Indian crude oils (viz Heera and Jodhpur) of different specific gravity were obtained by precipitation of VRs in n-hexane, n-heptane, and ethyl acetate, and also by subsequent reprecipitation of n-heptane and ethyl acetate soluble fractions by n-pentane The effect of various solvents on average molecular structure of asphaltenes and insolubles was studied using nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FTIR), and size exclusion chromatography (SEC) The asphaltenes and insolubles of Jodhpur VR have higher amounts of high molecular weight species with a high concentration of condensed and substituted aromatic rings, branched and/or short alkyl side chains, oxygen and nitrogen functionalities, compared to that of Heera VR Ethyl acetate insolubles comprise a higher number of substituted aromatic structures, branched aliphatic structures, complex average unit structures, nitrogen and oxygen functionalities, and high molecular weight (MW) species as compared to hexane and heptane asphaltenes Heptane insolubles consist of more naphthenic rings condensed with aromatic rings than C6A and EAI
36 citations
TL;DR: In this paper, a systematic study for a concept governing support effect in heavy oil hydrotreating (HDT) catalysts is performed, which confirms that coke and metals deposition on the surface of catalyst is most probably near the pore mouth.
Abstract: A systematic study for a concept governing support effect in heavy oil hydrotreating (HDT) catalysts is performed. Different Al2O3 and its mixed oxides supports were prepared and CoMo supported catalysts were tested for Maya heavy crude oil hydrotreating. Fresh and spent catalysts are characterized with N2 adsorption-desorption, element analysis, and scanning electron microscopy-energy dispersion analysis by x-ray (SEM-EDAX), which confirms that coke and metals deposition on the surface of catalyst is most probably near the pore mouth. It is also demonstrated from these results that asphaltene conversion depends on the pore diameter of the catalyst, while other hydrotreating conversions (hydrodesulfurization (HDS), hydrodenitogenation (HDN), and in some extent hydrodemetallization (HDM)) are more likely affected by the nature of active metal distribution. The evaluation of alumina mixed oxide (TiO2, ZrO2, B2O3, and MgO) supported catalysts indicates that supports with basic nature have better sta...
33 citations
TL;DR: In this paper, a waxy crude oil (pour point = 21°C and wax content = 18.9 wt%) was treated with four synthesized additives as pour-point depressants and determined using x-ray diffractometer.
Abstract: α-Olefin maleic anhydride copolymers were prepared by reacting C8 or C14 olefin with maleic anhydride, then esterified with dodecyl or NAFOL 1822B alcohol, purified and characterized through average molecular weight, polydispersity index, and infrared spectroscopy. A waxy crude oil (pour point = 21°C and wax content = 18.9 wt%) was treated with the four synthesized additives as pour-point depressants and determined using x-ray diffractometer. It is found that the x-ray diffraction patterns of waxes with additives are remarkably different from those without additives. The NAFOL 1822B ester of 1-tetradecene maleic anhydride copolymer also show stronger interaction with the wax than NAFOL 1822B ester of 1-octene copolymer, dodecyl ester of 1-tetradecene maleic anhydride copolymer, and dodecy ester of 1-octene maleic anhydride copolymer. These effects can be attributed to the chain length of side hydrocarbon. The wax solubilization is a function of copolymer.
32 citations
TL;DR: In this paper, asphaltenes were extracted from vacuum residues of Heera (HVR) and Jodhpur (JVR) Indian crude oils using n-hexane, n-heptane, and soluble and insoluble fractions obtained using ethyl acetate, were characterized for elemental analysis, molecular weight, conradson carbon residue (CCR), specific gravity, and pour points.
Abstract: Solvent separation is frequently applied to petroleum vacuum residues to reduce the coke-forming tendencies of these materials. This process is capable of removing all or a substantial amount of asphaltenes from feedstocks that are destined for further processing and thus applied as the first step of refining. Maltenes and asphaltenes obtained from vacuum residues of Heera (HVR) and Jodhpur (JVR) Indian crude oils using n-hexane, n-heptane, and soluble and insoluble fractions obtained using ethyl acetate, were characterized for elemental analysis, molecular weight, conradson carbon residue (CCR), specific gravity, and pour points. The resulting degree of removal of asphaltenes ranged from 10–28 wt% of the HVR and 25–50 wt% of the JVR. The increasing trend of the American Petroleum Institute (API) gravity and the decreasing trend of CCR and pour point are observed with the increase in removal of asphaltenes.
29 citations
TL;DR: In this paper, a simple Fourier transform infrared (FTIR) analysis spectroscopy was adapted to the determination of aromatic hydrogens in asphaltenes and resins and elucidation of their average molecules.
Abstract: Asphaltenes are components of crude oil, and their average chemical structures are characterized with difficulty. This study shows that simple Fourier transform infrared (FTIR) analysis spectroscopy could be adapted to the determination of aromatic hydrogens in asphaltenes and resins and elucidation of their average molecules. The work demonstrates the existence of a linear correlation in the infrared (IR) intensities of the symmetric and asymmetric aromatic hydrogens in methyl substituted arenes, in the 2,900 to 3,100 cm−1 region and of the out-of-plane deformation in the 700 to 900 cm−1 region.
29 citations
TL;DR: In this paper, the authors show that previously reported UV/vis spectra of asphaltenes/crude oils may have been strongly distorted by artifacts, affecting not only quantitative parameters (spectra's slopes), but also qualitative features (a presence of strong UV peaks).
Abstract: New experimental data show that previously reported UV/vis spectra of asphaltenes/crude oils may have been strongly distorted by artifacts, affecting not only quantitative parameters (spectra's slopes), but also qualitative features (a presence of strong UV peaks). In a popular revised “amorphous semiconductor” (AS) model, the properties of UV/vis spectra are defined by population distribution of higher aromatics. This interpretation is obviously incompatible with the newly observed concentration effects in toluene solutions. Possibly, some specific features of UV/vis absorbance in asphaltenes/crude oils may be better described by the traditional AS model, taking into account the distribution of defects in chromophore carriers, e.g., nanosized carbonaceous species of the graphene family.
TL;DR: In this paper, a review covers publications in the open literature and patents issued during the last 10 years on issues related to fluid catalytic cracking (FCC) gasoline sulfur reduction.
Abstract: This review covers publications in the open literature and patents issued during the last 10 years on issues related to fluid catalytic cracking (FCC) gasoline sulfur reduction. Emphasis was placed on FCC additives, their composition and performance. An attempt was made to elucidate the mechanism for sulfur reduction at FCC cracking conditions. Fluid catalytic cracking technology advances, both process and catalyst, have historically worked together to achieve significant improvements in FCC performance. There is every reason to expect that this will continue to be the case in the future. These advances will have an impact on the volume and quality of the FCC gasoline produced and will offer additional operating flexibility.
TL;DR: In this article, the effect of asphaltene contained in heavy crude on the deactivation of NiMo catalysts was studied. But the authors focused on the degradation of the catalysts.
Abstract: The effect of asphaltene contained in Maya heavy crude on the deactivation is studied. Different heavy feeds are prepared by the mixing of Maya with desulfurized diesel. A standard NiMo catalyst is used in a batch reactor to evaluate hydrodemetallation (HDM), hydrodesulphurization (HDS), and asphaltene (HDAsp) conversion. Textural properties of the spent catalysts are studied by pore size distribution and x-ray diffraction (XRD). Metals and coke deposition on the deactivated catalysts are also measured. It is found that HDM and HDAsp activities decrease with increasing concentration of asphaltene in feed, whereas the opposite trend is observed in the case of HDS. Both deposits of coke and vanadium on the catalyst's surface increase with the concentration of asphaltene in feed. The presence of asphaltene is the main reason to decrease surface area and total pore volume and hence it causes deactivation.
TL;DR: In this paper, a model of artificial neural networks (ANNs) using back propagation (BP) is developed for modeling thermal cracking of naphtha, and the optimum structure of the neural network was determined by a trial-and-error method.
Abstract: Thermal cracking of naphtha has such numerous reaction routes that the detailed reaction mechanism has not yet been determined. In this regard, a model of artificial neural networks (ANNs), using back propagation (BP), is developed for modeling thermal cracking of naphtha. The optimum structure of the neural network was determined by a trial-and-error method. Different structures were tried with several neurons in the hidden layer. The model investigates the influence of the coil outlet temperature, the pressure of the reactor, the steam ratio (H2O/naphtha), and the residence time on the pyrolysis product yields. A good agreement was found between model results and experimental data. A comparison between the results of the mathematical model and the designed ANN was also conducted and the relative absolute error was calculated. Performance of the ANN model was better than the mathematical model.
TL;DR: In this article, the emission factor approach was employed to predict the emission potential of volatile organic compounds (VOCs) from both operating and proposed petroleum refineries in Nigeria, and the emission sources from the refineries (4 operating and 14 newly licensed) were classified as point and area with anticipated VOC release into the environment estimated.
Abstract: The emission factor approach was employed to predict the emission potential of volatile organic compounds (VOCs) from both operating and proposed petroleum refineries in Nigeria. The emission sources from the refineries (4 operating and 14 newly licensed) were classified as point and area with anticipated VOC release into the environment estimated. The overall contribution was also estimated using human population and land mass distribution. The no-control-measure option gave estimated VOCs from the existing 4 petroleum refineries located in the states of Delta, Kaduna, and Rivers as 147,212 ton/annum (if operated at full capacity), while the successful construction and commissioning of the approved 14 refineries located in the states of Akwa Ibom, Anambra, Cross River, Delta, Lagos, Ogun, Ondo, and Rivers can raise this by about 240%. Rivers State with the highest number of refineries has the highest emission distribution per head while Lagos State has the least; the southern part of the country...
TL;DR: Asphaltenes obtained from raw vacuum residue from Russian (Ural) petroleum have been characterized by means of elemental analysis and 1H proton nuclear magnetic resonance (NMR) as discussed by the authors.
Abstract: Asphaltenes obtained from raw vacuum residue from Russian (Ural) petroleum have been characterized by means of elemental analysis and 1H proton nuclear magnetic resonance (NMR) and compared with asphaltenes separated from the residue desulfurized in the H-oil process. The latter have much lower molecular weight and more aromatic character. In high-temperature conditions of fractionation of the whole H-oil product and in the presence of catalyst dust carried away from reactors, asphaltenes tend to condense, dehydrogenate, and separate from the desulfurized oil as a coke-like sediment. Some correlations have been found between the asphaltene contents of raw and desulfurized residue and the tendency of sediment formation in desulfurized residual oil that causes serious operating problems in H-oil units.
TL;DR: In this article, a hybrid method for modeling discrete fracture network in an actual naturally fractured reservoir (Palm Valley, Australia) is presented. And the results show an improvement of the hybrid method over previous fracture models.
Abstract: This article presents application of a hybrid method for modelling discrete fracture network in an actual naturally fractured reservoir (NFRs) (Palm Valley, Australia). The hybrid method integrates features of geological, statistical, artificial intelligence, and conditional hierarchical stochastic simulation techniques. Both discrete and continuum fracture information could be utilized, such as statistical distributions of fracture orientations, spatial distributions of fracture density, and discrete multi-fractal dimensions. The final output is a 3D network model of discrete fractures, with their corresponding details of location, size, and orientation. The results show an improvement of the hybrid method over previous fracture models.
TL;DR: The basic mechanisms and general characteristics of severe slugging in a pipeline-riser system are detailed and the research studies that have been carried out are presented in two parts; experiments on different flexible riser configurations, and existing OLGA code predictions.
Abstract: Flexible risers are key components of floating production systems, particularly in harsh environmental conditions where the riser must deal with substantial vessel motion. Liquid slugging in flexible risers often causes severe operational problems for the downstream production system. To avoid such costly delays, it would be desirable to predict severe slugging behavior in flexible risers using experiments and transient codes. This article details the basic mechanisms and general characteristics of severe slugging in a pipeline-riser system. It also tries to present the research studies that have been carried out on severe slugging in flexible risers in two parts; experiments on different flexible riser configurations, and existing OLGA code predictions.
TL;DR: In this paper, the carboxylic acid groups in asphaltene with the reactive ethylene terpolymer to form ester were used to improve features of 60/70 penetration grade, modified bitumen used on highways.
Abstract: Polymer modified bitumen (PMB) is used in various construction applications, especially in motorways. The aim of this study is to improve features of 60/70 penetration grade, modified bitumen used on highways. Increasing the sensitivity to temperature and oxidation resistance are very important points for the modified bitumen. This condition was provided by reacting the carboxylic acid groups in asphaltene with the reactive ethylene terpolymer to form ester. Reactive ethylene terpolymer (RETP) and ethylene terpolymer (ETP) manufactured by DuPont USA were used as additives in this study. Infrared Spectrophotometer (IR) graphics and optical pictures of the modified bitumen have been examined. It has been observed that the softening point has increased on the other hand, the penetration and ductility values have decreased according to the test results.
TL;DR: In this article, it is shown that these kinetic parameters are invariant with respect to residue compositions and therefore this model is able to predict yields of delayed coking products for a wide variety of ranges of charge stock and operating conditions beyond that of the tests.
Abstract: Lumping of the residue charge stock is based on saturate, light and heavy aromatics, soft and hard resins, as well as asphaltenes, whose concentrations can be obtained by solvent sedimentation and Al2O3 column separation. The reaction scheme contains 11 lumped species, including two middle fractions, naphtha, gas, and coke in addition to the above six lumps for residua. It is shown that these kinetic parameters are all invariant with respect to residue compositions and therefore this model is able to predict yields of delayed coking products for a wide variety of ranges of charge stock and operating conditions beyond that of the tests.
TL;DR: Asphaltenes from Iranian Light, Khafji and Maya were cracked in batch reactors at 350, 370, 390, 410, and 430°C under hydrogen to produce liquid products for kinetic analysis as discussed by the authors.
Abstract: Asphaltenes from Iranian Light, Khafji and Maya were cracked in batch reactors at 350, 370, 390, 410, and 430°C under hydrogen to produce liquid products for kinetic analysis. The cracking kinetics of the asphaltenes and their intermediates were analyzed on a total molar basis, to avoid the assumptions inherent in lumped kinetics. The overall reactivity of the three asphaltenes was similar for reaction times from 1 to 37 min. The behavior of Khafji was distinct in its initial high reactivity of sulfur species, while the high yield of hydrocarbon gases from Iranian Light was likely due to the poly-alkyl side chains of the aromatic rings. The apparent first order activation energies were in between 170 and 255 KJ/mol. The activation energies were in the sequence Iranian Light > Maya > Khafji.
TL;DR: In this paper, the organic geochemical and biomarker analyses of the Miocene source rocks of some wells in the onshore Nile Delta, suggested that the Abu Madi Formation has poor immature to marginally mature source rock of Type III Kerogen deposited under the terrestrial environment.
Abstract: The organic geochemical and biomarker analyses of the Miocene source rocks of some wells in the onshore Nile Delta, suggested that the Abu Madi Formation has poor immature to marginally mature source rocks of Type III Kerogen deposited under the terrestrial environment. The Sidi Salem Formation has fair-to-good mature source rocks of producing mixed oil and gas, originating mainly from marine organic sources. The Moghra Formation has mature good source rocks for Type (II/III) kerogen, derived from organic matter and rich in both terrigeneous and marine sources. The geochemistry of condensates revealed that the Abu Madi and Moghra condensates originated from marine organic matters with little input from a terrestrial source, while Sidi Salem condensate was derived from more contribution of terrestrial organic matters. Abu Madi condensate is less mature than Sidi Salem and Moghra condensate. The geochemical thermal modeling of the Miocene source rocks indicates that the Abu Madi formations are in ...
TL;DR: In this paper, a new extrapolation procedure, the direct reduced flash (DRF), is formulated for the selected set of independent variables, taking into account both changes in pressure and composition.
Abstract: A possibility for reducing the dimensionality of the phase equilibrium problem is given by the reduction method. The number of independent variables for reduced phase equilibrium calculations is independent of the number of components in the mixture. For two-phase flash calculations, the number of independent variables is m + 2, where m is the number of non-zero (or non-negligible) eigenvalues of the matrix with (1 − k ij ) elements (k ij denotes the binary interaction coefficient between components i and j). In this work, a new extrapolation procedure, the direct reduced flash (DRF), is formulated for the selected set of independent variables, taking into account both changes in pressure and composition. This non-iterative extrapolation algorithm is particularly efficient when results of previous flash calculations, performed at some close reference conditions (pressure and composition), are available. This is the case for most of the phase equilibrium calculations performed during a composition...
TL;DR: In this paper, the effects of the operating conditions on the evolution of asphaltenes and on their inhibition effect during the hydrodesulfurization reactions were analyzed and significant changes in the average structure were also observed.
Abstract: Residue upgrading processes are very important for the production of distillates and low sulfur fuel oils. Among those, fixed bed technologies are very efficient for deep desulfurization of petroleum residue heavy oils, even for highly asphaltenic feeds. This work analyzes the effects of the operating conditions on the evolution of asphaltenes and on their inhibition effect during the hydrodesulfurization reactions. Residue hydrotreating experiments were performed on a pilot plant and asphaltene fractions were investigated using size exclusion chromatography (SEC), 13C nuclear magnetic resonance (NMR), liquid chromatography, and elemental analyses. Besides the overall decrease in asphaltenes yield, significant changes in the average structure of the asphaltenes were also observed.
TL;DR: Active carbons were prepared by the steam activation of a brown coal char as mentioned in this paper, and the active carbon with mesopores showed greater adsorption selectivity for asphaltenes.
Abstract: Active carbons were prepared by the steam activation of a brown coal char. The active carbon with mesopores showed greater adsorption selectivity for asphaltenes. The active carbon was effective at suppressing coke formation, even with the high hydrocracking conversion of vacuum residue. The analysis of the change in the composition of saturates, aromatics, resins, and asphaltenes in the cracked residue with conversion demonstrated the ability of active carbon to restrict the transformation of asphaltenes to coke. The active carbon that was richer in mesopores was presumably more effective at providing adsorption sites for the hydrocarbon free-radicals generated initially during thermal cracking to prevent them from coupling and polycondensing.
TL;DR: In this paper, the effect of adding Ti and P to NiMo/ab Al2O3 catalysts in heavy Maya crude was investigated and the results showed that not all the catalyst functionalities respond equally well to the addition of Ti and p to the catalyst formulation.
Abstract: The effect of adding Ti (4.5 wt%) and P (∼1.0 wt%) by several routes to a NiMo/ab Al2O3 catalyst on the hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodemetallization (HDM), and hydrodeasphaltenization (HDAs) of heavy Maya crude was investigated. The results show that not all the catalyst functionalities respond equally well to the addition of Ti and P to the catalyst formulation. There is not a single catalyst formulation that can achieve optimum performance in all the catalyst functionalities. For HDS, Ti incorporation increases activity but the route by which P is added afterwards can improve or be detrimental to HDS activity. For HDN, the incorporation of P to the catalyst can lead to significant improvements in catalytic activity and catalyst stability. Ti increases HDM activity but the addition of P to the catalyst is detrimental to this functionality. For the elimination of asphaltenes, the catalyst supported on pure alumina is the best. So for HDAs, no benefit is obtained by...
TL;DR: In this article, the authors developed a simple, accurate, and reliable empirical equation for estimating the asphaltene deposition envelope (ADE) by determining the upper and lower onset pressures as well as the saturation pressures.
Abstract: There has been an increasing interest in the construction of asphaltene deposition envelope (ADE) to determine a safe zone of operation during oil production. Equations of state are usually used for calculations of ADE; however, the method requires tuning some experimental Pressure Volume Temperature (PVT) data of the reservoir fluid. The objective of this study is to develop a simple, accurate, and reliable empirical equation for estimating the ADE by determining the upper and lower onset pressures as well as the saturation pressures. Three simple empirical equations are developed to calculate these onset pressures of several crude oils. Experimentally measured compositions, saturation, and onset pressures of 33 crude oil samples, primarily from the Middle East, at different temperatures were used to develop the equations. Another set of compositions and upper saturation and lower onset pressures of different crude oil samples from the literature were used to test the accuracy of the empirical e...
TL;DR: In this paper, a series of experiments on two-phase, air-water flow in a flowline-riser geometry have been made, and the authors identify areas that pose substantial difficultly to the code for the simulation of severe slugging in a catenary-shaped riser.
Abstract: A series of experiments on two-phase, air-water flow in a flowline-riser geometry have been made. The riser has a catenary-shaped form (10.5 m high), and the flowline has a 2-degree downward inclination toward the riser-base (10.16 cm ID). Experimental data were used to characterize the severe slugging and unstable flows in terms of pressure cycling and fluid production characteristics. A model to study dynamic behavior of severe slugging flow in a pipeline-riser system was also developed under the environment of the OLGA2000 code, and experimental test results were compared with the OLGA model predictions. The motive for this work was to identify areas that pose substantial difficultly to the code for the simulation of severe slugging in a catenary-shaped riser. In addition, numerical experiments, exploring some of the reasons for difference between experimental and simulation results, have been presented in this article.
TL;DR: A review of the vapor extraction process and its variations can be found in this paper, which describes important factors affecting the process such as solvent requirements, mass transfer, asphaltene precipitation, oil rate, and wettability.
Abstract: The high viscosity of Canadian crude oil is a serious challenge for the recovery efficiency of this resource by conventional methods. Since 1991, the vapor extraction process (VAPEX) has emerged as a promising technology that has gained considerable attention within the oil industry. This article presents a current review of this process and its variations, as well as describing important factors affecting the process such as solvent requirements, mass transfer, asphaltene precipitation, oil rate, and wettability. Recent research has shown that VAPEX is an efficient alternative for the recovery of heavy oil.
TL;DR: In this article, the properties, chemical composition, and structural composition of coker gas oil from Daqing, Shengli, and Liaohe saturated hydrocarbon fields were analyzed.
Abstract: The coker gas oil from Daqing, Shengli, and Liaohe, which are three famous oil fields in China, are studied. The properties, chemical composition, and structural composition of coker gas oil from Daqing, Shengli, and Liaohe saturated hydrocarbon are analyzed. The results show that nitrogen and sulfur content in Daqing coker gas oil is the lowest, and saturated hydrocarbon content is the highest, and Daqing coker gas oil is the most easily processed raw material, and Liaohe coker gas oil mediates between two raw materials, but Shengli coker gas oil is the most difficult to process. By comparing with vacuum gas oil and nitrogen, sulfur content and carbon residue in the coker gas oils is higher and saturated hydrocarbon content is lower. Shengli coker gas oil is a somewhat inferior raw material. The factor of effecting on the processing and use of coker gas oil are analyzed, and the processing ways of coker gas oil are put forward.