Petroleum Science and Technology

Published by Taylor & Francis
Online ISSN: 1532-2459
Print ISSN: 1091-6466
Publications
A pressure and temperaturedie preservation system (PTPS) is developed for natural gas hydrates (NGH) sampler. First, some pressure-coring tools for gas hydrate and free gas investigation are reviewed. Then a PTPS with length of 11.2 m and diameter of 60 mm is developed which can be divided into 4 parts with a length of less than 4 m for each part. Laboratory experiments shown that this new PTPS was suitable for maintaining the pressure and temperature of ice and water mixture. Further, this new PTPS was applied during the HY4-2006-03 voyage of No. 4 ocean ship on the northern part of the South China Sea, and two pressurized sediments of 85 and 100 cm length were obtained. All laboratory experiments and applications show that the max. operating depth and sample length of this PTPS are 3000 m and 10 m, respectively, the PTPS has a good ability of recovering sediment samples on the seafloor and maintaining their original in-situ pressure and temperature, meeting the requirement of exploration of NGH in deep-sea shallow sediment layers.
 
Emulsification is an undesired phenomenon in the refining of highly acidic oil by alkali-washing electro-refining. In this article, a novel microwave method is applied for demulsification in the removing of naphthenic acid from diesel oil. The internal heating is attributed to molecular rotation and ionic conduction. The decrease of interface zeta-potential and the viscosity of diesel oil are responsible for the demulsification with microwave irradiation. The results exhibited that the demulsification rate is maximized when the optimum microwave irradiation power, exposure time, and irradiation pressure for Anshan and Liaohe diesel oil are deemed to be 375 W, 5/6 min and 0.05 MPa, respectively.
 
The changes of n-pentane asphaltene content, penetration, softening point, and ductility of two Saudi Arabian paving asphalts have been studied during aging. Further, aging kinetics of asphalt, based on the change of n-pentane asphaltene content, has been studied. Some correlative kinetic parameters were calculated and the aging kinetics equation of asphalt was gained. The value calculated depending on the equation was in accordance with the experimental data. And the relationship between the composition of the high grade paving asphalt and its aging resistant performances was revealed. It showed that the aging of high grade paving asphalt was a first-order reaction. AH-70 paving asphalt has the following characteristics: higher reaction active energy, less reaction velocity constant, lower aging velocity, and better aging resistance performance compared with AH-90 paving asphalt. The changes of penetration, softening point, and ductility of asphalt during aging further proved that the kinetic model is reliable.
 
The paper introduces the mechanism and kinetics of the alkylation of benzene with ethylene to produce ethylbenzene. The alkylation reaction mechanism that takes place in the surface of the ZSM-5 catalyst and the [bmim]Cl/FeCl 3 ionic liquid catalyst is described; at the same time the alkylation reaction kinetics is put forward based on the corresponding mechanism. The method obtained aids in the understanding of the microcosmic process of alkylation for adapting to the necessity of industrialization.
 
To simulate multiphase flow in complex recovery processes such as water alternating gas (WAG), it is essential to consider the influences of saturation history on relative permeabilities and capillary pressures of the present phases. This effect, which is known as hysteresis, is generally handled by use of empirical models, and deciding which combinations of hysteresis options and parameters are appropriate for a specific study is required. This study investigates how reservoir simulation results are influenced by the use of different modeling options for hysteresis effect in three-phase flow. Hysteresis models were categorized for wetting and nonwetting phases, and they were applied to relative permeability and capillary pressures. In addition, sensitivity analysis was performed on effective parameters on hysteresis behavior of relative permeability. Laboratory hysteresis data were used in simulation of an immiscible WAG process. It was observed that including hysteresis options in simulation influenced the outputs significantly, mainly on oil recovery and breakthrough times (water and gas). Changing the type of nonwetting model had a negligible influence on the results, whereas the type of wetting hysteresis option had a considerable effect on prediction of recovery and breakthrough times. Furthermore, using hysteresis, capillary pressure was found to have a very weak effect on the outputs. Finally, it was observed that the significance of the hysteresis effect is very sensitive to imbibition residual saturation of oil in the presence of water.
 
The effect of mixing both local Egyptian hematitic ore and activated aluminosilicate material (bentonite clay) on the dehydrogenation activity of the former was studied. Three mixtures were prepared in which bentonite percentages were 10, 20, and 40 wt%. Cyclohexane used as a model reactant for the catalytic dehydrogenation reaction carried out in catalytic flow system within reaction temperature ranged from 150 to 500°C in the presence of hydrogen stream (75 mL/min) and at constant space velocity 3.71 h −1 . The results obtained indicated that in spite of the drop in the selectivity of the local material toward benzene formation by clay addition, a distinct increase in the benzene yield was observed. The maximum conversion attained ∼28.14% at reaction temperature 500°C using a mixture containing 20 wt% activated bentonite.
 
In view of the high energy consumption inherent in the auxiliary riser fluid catalytic cracking (ARFCC) process, a new energy optimization design has been suggested in this paper to decrease its auxiliary system energy cost and improve its product quality. The heat distribution of an auxiliary fractional system has been optimized and its surplus heat was used to heat crude gasoline, making low-temperature liquid crude gasoline into gas, which was then fed into the auxiliary reactor. The application in an ARFCC unit with 75 t/h of crude gasoline to be reprocessed showed, after the energy optimization design, that when the crude gasoline feed was heated from 40°C to 219°C, the contact temperature difference between the feed and the regenerated catalyst reduced from 650°C to 322°C, process exergy loss decreased by 77.8%, and less dry gas and coke was formed in the auxiliary reactor. At the same time, the energy-use optimization of the auxiliary fractional system increased its exergy recovery efficiency by 25%, 9.73 GJ/hr more valid heat was recovered, and 23.5 t/h more medium pressure steam was produced by the heat of the regenerated catalyst replaced by gaseous crude gasoline. The total energy consumption of the ARFCC process was reduced by a 6.8 kgEO/t feed.
 
The hot storage stability of styrene-butadiene-styrene triblock copolymer (SBS)-modified road asphalt can be improved significantly by reactive blending of SBS and asphalt under high share mixing at high temperature with elemental sulfur and vulcanization accelerator. The storage stability, morphology, and rheological properties were analyzed and evaluated by means of the hot storage test, fluorescent microscopy, and conventional and dynamic mechanical analysis using a dynamic share rheometer (DSR), respectively. The test results indicate that not only storage stability but also rheological properties of SBS-modified asphalt were enhanced by reactive blending of SBS and asphalt. Moreover, the addition of cross-linking agent resulted in the change in morphology of SBS-modified asphalt from a continuous asphalt phase with dispersed SBS particles to two interlocked continuous phases. The formation of a chemically cross-linked network enhanced the elasticity and deformation resistance of SBS-modified asphalt.
 
A lumped kinetic model for catalytic naphtha reforming with 27 lumps is developed in order to predict aromatic compositions in more detail. The 8-carbon aromatics are subdivided into ethylbenzene and xylene, and 9-carbon aromatics are subdivided into trimethylbenzene, methylethylbenzene, and propylbenzene, respectively. The simulation of a Universal Oil Products (UOP) commercial continuous reforming unit is carried out to validate the model. The results show that perfect agreement of compositions at the exit of the fourth reactor is obtained between simulated values and reported values and the mass contents of benzene, toluene, ethylbenzene, xylene, trimethylbenzene, methylethylbenzene, and propylbenzene are predicted accurately. The calculated temperature at the exit of each reactor is consistent with the actual value. The composition and temperature profiles are calculated, and the two-dimensional distributions of coke content of catalyst bed are simulated.
 
The results of a two-fluid model computational fluid dynamics (CFD) analysis of the bottom water draw-off system are presented. The simulated flow in the pipeline is segregated and consists of a water layer at the bottom and oil dispersion on top of it. CFD simulations allowed calculations of oil concentration in the bottom draw-off pipe and visualization of the behavior of the interface between the top and bottom fluid layers in the main pipe. A simplified one-dimensional analysis, which makes use of the CFD results is also performed and provides a useful chart that should aid the complex operation of the bottom water draw-off system.
 
Emulsification is an unwanted phenomenon in the refining of highly acidic oil by alkali washing electrorefining. In this work, a novel microwave demulsification method is applied in the removing of naphthenic acid. The internal heating is attributed to molecular rotation and ionic conduction. The decrease of Zeta-potential of interface and the viscosity of diesel oil are responsible for the acceleration of separation of naphthenic acid and demulsification with microwave irradiation. The results show that both the separation efficiency and the demulsification rate are maximum when the optimum microwave irradiation power, exposure time, and irradiation pressure are deemed to be 375 W, 5 min, and 0.05 MPa, respectively.
 
Layered shales in reservoir.
An illustration of the pseudo REVGS.
, the local method greatly underestimates large permeability values and
Permeability fields of the FIELD data set.
Realistic upscaling of fine-scale reservoir models is a great challenge for reservoir engineers. The common problem of conventional upscaling methods is that they may smear out the spatially continuous permeability extremes, such as shale barriers and open fractures. Recent studies have shown that such smearing effect has a significant impact on recovery in heterogeneous reservoirs, especially the breakthrough oil recovery. The conventional methods are considered as local upscaling which concentrate on only local areas and ignore geologically important structural information. A recent global upscaling approach attempts to solve this problem, but the resulting grid system may be over-irregular and becomes impractical for field applications. This paper presents an improved global upscaling approach based on the representative elemental volume (REV) theory and the stepwise idea from renormalization. The new method focuses on the use of a new concept of REVGS (REV Grid System) for constructing coarse blocks, which taking into account the spatial connectivity of a global permeability field. Mathematically, the variance of permeability in the coarse blocks is the smallest within the blocks, and the largest between the blocks. The resulting system can be readily used in flow simulators. The proposed method is applied to two case studies. Compared to the conventional methods, the coarse grid system derived from our improved global method successfully retains the permeability extremes observed in the fine-scale models. The flow simulation results show that the consistency of the reservoir behavior before and after upscaling is excellent.
 
This article takes the Saucier method as the foundation and aim at fracturing packing, under ideal gravel conditions, through the analysis of the pore of gravel bed in the condition of fracturing or high-pressure packing and the arch bridge theory to revise the Saucier method and put forward the design space of gravel-to-sand median diameter ratio (GSR) is 5.464-6.831, thereby providing the foundation for optimizing and gravel size decision with high-pressure packing control sanding.
 
This article addresses the use of Centric Scan SPRITE Magnetic Resonance Imaging (MRI) technique to visualize the performance of polymer flooding as a mobility-control technique. The fronts and interfaces between displaced and displacing fluids are monitored. The development of a piston-like displacement front, as a result of polymer-augmented waterflood, and the effect of polymer concentration on the development of a favorable water displacement front are directly observed. MRI demonstrates to be a useful imaging tool for the evaluation of the efficiency of polymer flooding. Experiments indicate a close agreement between fluid saturations determined by MRI and fluid saturations estimated from material balance.
 
In the past two decades, a great many upscaling procedures have been proposed. The major methods are power-law average, renormalization technique, pressure-solver method, tenser method, and pseudofunction technique. The common problem of conventional upscaling methods is that they tend to smear out the spatially continuous extremes, such as shale barriers and open fractures. However, experience and previous simulation works in heterogeneous reservoirs have shown that oil recovery (especially water breakthrough oil recovery) mainly depends on the spatial connectivity of the extreme permeability values.The main idea of upscaling is to replace a number of heterogeneous fine grid blocks with one equivalent coarse homogeneous grid block. So, the essence of upscaling is averaging. Therefore, we think that all upscaling approaches could be sorted as two types. One is explicit averaging model: including power law averaging, renormalization technique, and global upscaling. The other is implicit averaging model: pressure-solver methods and pseudofunctions. If regarding their theoretical strategies, we may classify them as another two types, one is grid-upgridding-oriented approaches, such as global upscaling, sedimentological approach of upscaling; and the other is property-upscaling-oriented approaches, which include most of the traditional upscaling methods. It goes without saying that some information loss in upscaling is inevitable. The key issue is how to optimize the upscaling technique and minimize the information loss. Lasseter et al. (1986)19. Lasseter , T. J. , Waggoner , J. R. and Lake , L. W. 1986. “Reservoir heterogeneities and their influence on ultimate recovery”. In Reservoir Characterization, Vol. 545, Orlando, Florida: Academic Press Inc.. View all references proposed that scaleup of properties should be done from the scale of a representative elementary volume (REV), a volume for which the measured property does not change with an increase in scale over a given limit of scale. The notion of REV is physical-model oriented and proposed a criterion for upscaling technique. However, the decisive factor in upscaling is the grid system rather than individual physical point.This paper concludes that how to obtain REV for real system, how to evaluate the upscaling results quantitatively, how to treat extremes of permeability as well as how to perform upscaling for naturally fractured reservoirs and carbonate reservoirs are the remaining major challeng problems in this area. It is concluded that a great effort should be made on how to obtain the REV grid, which could best describe the heterogeneity of given reservoir at given scale. Second, how to perform the upscaling of all properties based on REV grid is also a critical aspect and should be considered according to different extent and pattern of heterogeneity of original geological model, respectively.
 
Transport properties of transformer oil are important parameters for electric equipment designing. In this work, thermal conductivity was measured from 253 K to 363 K by single transient hot-wire technique. And influence of transformer oil's thermal conductivity was investigated. It is found that the thermal conductivity decreases linearly with increasing temperature. When different oils are mixed together, the thermal conductivity shows additive property. For different oils with about the same viscosities, their thermal conductivities are directly related to alkane and aromatic content, while for oils with the same oil source, oil refinery process, similar carbon type, and different boiling range, the thermal conductivity increases with its viscosity.
 
Fuels from Japan, Senegal, and Turkey were investigated to determine the organic nitrogen content. The organic nitrogen compounds were isolated by mild acid extraction followed by silica gel adsorption. Three extracts were obtained from each sample: a basic nitrogen extract in methylene chloride (BNC); a non-basic nitrogen extract in methylene chloride (NBNC); and a non-basic nitrogen extract in methanol (NBNC). The constituents of each extract were determined by high-resolution gas chromatography/mass spectrometry (GC/MS). Common nitrogen compounds identified were pyridines, tetrahydroquinolines (THQs), quinolines, indoles, pyrroles, and carbazoles. The largest number of compounds identified in all three fuels was the pyrroles, followed by the indoles and pyridines, carbazoles, quinolines, and THQs.
 
Percentage distribution of hydrogen and carbon atoms in insolubles of JVR estimated by NMR spectroscopy
Average number of carbons and hydrogens per molecule and per unit sheet r from NMR data and elemental composition of insolubles
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.
 
Isobutane/2-butene alkylation catalyzed by binary mixtures of acidic ionic liquids (ILs) and strong acids (sulfuric acid or H2SO4 and triflic acid or CF3SO3H) was investigated. The catalytic performances of H2SO4 and CF3SO3H were considerably improved when ILs were added. Using [Emim][OTf]-CuCl/H2SO4 as the catalyst, an alkylate with a high content of the desired trimethylpentane (up to 79.6 wt%) and a high research octane number (up to 99.1) was obtained. The results of electrospray ionization-mass spectrometry indicated that the better distributions of the products obtained with the IL/acid mixtures were due to the Cu-containing anions and cations of the ILs.
 
Adaptive neuro-fuzzy inference system (ANFIS) is a powerful nonlinear, multivariable regression technique. Here ANFIS was used to identify complex relation between water-oil relative permeability key points and rock and fluid properties. Some 260 relative permeability curves from Iranian carbonate and sandstone reservoirs were used in this study. For each curve six key points (i.e., end points and the crossover points) were considered. ANFIS was then used to predict these key points from different rock and fluid properties. The results showed that very high correlation coefficients in the range of 0.8–0.92 are achievable for Kr key points. ANFIS is a very suitable tool therefore to obtain un-normalized water-oil relative permeability curves with high accuracy when the required core and fluid properties are available.
 
A comparative study of additive performance (viscosity modifier [VM], pour point depressant [PPD], and anti wear [AW]) of homo polydecylacrylate (D) and its blend with three different types of liquid crystals (each containing three samples) has been performed. Very low concentrations (100 ppm) of liquid crystals are used in this study and processes include synthesis of D, characterization (FT-IR, NMR) and evaluation. A comparison based on performances has been made among the three different series of liquid crystals (LC) blended homo polydecylacrylate (D). The study indicates the LC blended additives are far better in AW performance compare to only D and their VM and PPD properties are comparable with D and amongst all the three series of liquid crystals, AW performance is better for long alkyl chain length sample. Multifunctional additive performance of this kind of LC blended polyacrylate is reporting for the first time.
 
Sodium hydroxymethyl lignosulfonate (NaHLS) was prepared by hydroxymethylation of sodium lignosulfonate (NaLS) with formaldehyde. NaLS and NaHLS were characterized using Fourier transform infrared (FTIR) and transmission electron microscopy. The performance of NaLS- or NaHLS-modified drilling fluid was evaluated. The results showed that both NaHLS and NaLS can be used as low-temperature thickeners, high-temperature thinners, and filtration-loss control agents. For each of the technical performance measures, NaHLS is more effective than NaLS under any condition, especially under higher temperatures (180°C). In addition, the performance of NaHLS is similar to that of ferric chomium lignin sulfonate (FCLS), which means that it can be developed as a chromium-free drilling fluid additive. A test of the influence of NaHLS on the growth of wheat seedlings showed that NaHLS solution benefits the growth even better than a commercial culture solution.
 
Polydecylacrylate (PDA) is synthesized, characterized (FT-IR and NMR), and evaluated for its performance as anti wear (AW), pour point depressant (PPD), viscosity modifier (VM), and thickening agent in lube oil of different compositions. In addition physical blend of it with liquid crystal (LC) of cholesteryl benzoate (CB) is also made and evaluated, and the data is compared. Molecular weight of the prepared polymer and that of it blends was determined by viscometric analysis. The blends showed better efficiency to act as multifunctional (AW, PPD, VM) additives compare to the pure homopolymer in lubricating oil.
 
Twelve terpolymeric additives were prepared via free radical chain addition polymerization. The rheological properties of lube oil (SAE-30) were studied with and without additives. The prepared terpolymers have a good effect on the viscosity-temperature relationship. The flow curves and viscosity-shear rate curves of the prepared additives doped with lube oil were studied and it was found that they behave as Bingham fluids. The sensitivity of the prepared terpolymers to mechanical stresses was studied and it was found that the sensitivity increases with increasing the molecular weight of the prepared additives.
 
RCA X ray diffraction results Q Quartz, maximum at 4,150 counts 
Boiling Water Test results. Bitumen coverage after 24 hours: a) Control mixture, b) RCA with grey Portland cement filler, c) RCA left in the oven for 4 hours and d) RCA coated with bitumen emulsion. a) Control mixture (20% of bitumen coverage) b) RCA with grey Portland cement filler (80% of bitumen coverage) 
In this investigation, rolling bottle tests and boiling water tests were conducted to evaluate the effect of different fillers and treatments on the adhesion between recycled concrete aggregates (RCA) and asphalt. The test results when 100% RCA loose mixtures were evaluated indicated that the filler that achieves the best asphalt aggregate bond was grey Portland cement. Curing the mixture in an oven for 4 h at mix temperature before compacting and coating RCA with bitumen emulsion are treatments that achieved satisfactory adhesion results as well.
 
In adiabatic FCC regenerators, the classical approach of design and control of continuous stirred tank reactors identify stable steady states. This kind of reactors is a particular case of lumped parameter nonlinear systems. The easiness of regulation of the steady operating states depends on the relationship between system dynamics and control scheme. There have been several attempts for the evaluation of this relationship by systematic approaches, however the nonlinearities of these systems have troubled the evaluation goals. In partially controlled systems, such as chemical reactors, dynamic interactions among process variables might exhibit unexpected responses to control actions when the system is operating in some particular regions. These responses depend on the selection of control and manipulable variables. In this work, a methodology for the evaluation of control strategies is used to identify possible troubles when production objectives and process dynamics are noncompatible. The methodology is easy to understand and to apply to nonlinear lumped parameter systems that present control affine structure. Because the proposed methodology is independent of the kind of control used and the full process model is evaluated, it is possible to study the system behavior at any operating condition. An adiabatic FCC regenerator is used as example of the methodology application; three common production objectives are evaluated. Recommendations for the selection of operation objectives are given.
 
Tectonic sketch map of the Kuangshanliang Area of the Sichuan Basin (Reprinted from Marine and Petroleum Geology, 37(1), L. Wu, Y. Liao, Y. Fang, A. Geng, The study of the source of the oil seeps and bitumens in the Tianjingshan structure of the northern Longmen Mountain structure of Sichuan Basin, China, Pages 147-161, Copyright (2012), with permission from Elsevier).
TIC chromatograms of n-hexane eluates from soluble components of solid bitumen extracted with various solvents. Bitumen-1 through Bitumen-6 (B1-B6) indicate samples taken from different sites; (a), (b), and (c) represent n-hexane, acetone, and dichloromethane extracts from solid bitumen, respectively.
Mass spectra of m/z 85 ions in n-hexane eluates of oxidative degradation products of solid bitumen.
The geochemical characterizations of adsorbed and occluded components of solid bitumen in the Kuangshanliang area of northwestern Sichuan Basin were studied by comparing the results of conventional extraction and mild oxidative degradation. The results indicate that the solid bitumen originated from Sinian–Cambrian ancient oil reservoirs. The main source of the parent material is lower-order aquatic deposited in a high-sulfur anoxic marine environment. Exposed solid bitumen suffered from severe biodegradation, altering the tricyclic terpane/pentacyclic terpane and (pregnane + homo-pregnane)/regular sterane ratios as compared to the earlier parent material.
 
The injection of chemical solutions plays an important role in increasing the recovery factor of mature fields. Chemical flooding is considered as an attractive alternative to conventional waterflooding; it can improve the area sweep efficiency not only at the macroscale but also in the microscale by control mobility of displaced fluid. Adsorption of polymer in reservoir rock is an extremely important parameter for chemical flooding. Adsorption represents a loss of chemical agent from solution and, consequently, a net reduction in the surfactant–polymer slug. Therefore, the efficiency of polymer flooding is significantly diminished both technically and economically. However, numerical simulation of multicomponent adsorption is still limited and adsorption processes in a polymer–rock system have not yet been well developed, especially for highly heterogeneous reservoirs. In this article, adsorption was modeled by the Langmuir isotherm theory. The simulation results indicated that polymer adsorption strongly depends on polymer concentration, shear rate, pH, salt concentration, and reservoir heterogeneity. Effective control of such parameters can reduce the effect of polymer adsorption to minimize chemical loss and improve the economic efficiency of chemical flooding processes.
 
An aged emulsion from polymer flooding was dewatered using demulsification and centrifugal separation, and factors of influence on electrical dehydration were investigated. The lowest moisture (0.12%) was achieved at 16000 rpm separated separation. In recycled oil, there were significantly decreases in content of nitrogen, impurities, and iron. The results of simulative electrical dehydration showed that a small amount of separated wastewater (10%) could increase current continually. However, the recycled oil can achieve a satisfactory result of dehydration even mixed with 30% wastewater. It indicated that polymer, impurities, resins, and asphaltene contributed to the electric field collapse of the electric dehydrator.
 
The presence of homogeneous porous media allows a uniform sweep during a waterflooding process, but it is very rare to find homogeneous reservoirs. The typical heterogeneous character of most formations causes an uneven production from different permeability sands in the reservoir. The preferential movement of the injected water to zones with less resistance to flow causes earlier water breakthrough time than if the formation was homogeneous. This phenomenon will exacerbate at offshore reservoirs and the wells with water production potential. To suggest a solution to this problem, the use of emulsions as a mobility control and selective plugging agent has been studied here. Three different W/O emulsion formulations were injected into high-permeable heavy oil saturated waterflooded sandpacks and the one with the best recovery factor was injected to sandpacks with different permeabilities. The change in oil recovery pattern is considered as the main aim of this work. Experiment results revealed that invert W/O emulsions with high viscosities could act as a selective plugging agent and help the displacement process.
 
In the present study, a new chemical formulation is designed by combining acrylic acid with the conventional alkali-surfactant-polymer (ASP) components. Acrylic acid generates precipitation inhibitor that dissolves insoluble salts. The salts known as precipitations are formed by the reaction of added chemicals with carbonate reservoir minerals or brine compositions. Various fluid-fluid compatibility tests were first performed to find an optimum acid-alkali ratio to keep ASP solutions without any precipitations for 30 days at 80°C. Using the optimum ratio, a comprehensive study was conducted to investigate the impact of acid, acid-alkali, and acid-alkali-surfactant on the viscosity of copolymer. The optimum acid-alkali ratio was found 0.6:1.0. It was observed that blend of acid with ASP solutions did not cause significant impact on the polymer viscosity. This new chemical combination provided sufficient viscosity for mobility control in the hard brine environment. Hence, the main feature of this work is the development of acid-ASP formulation, which can be more feasible for enhanced oil recovery in carbonate reservoirs as compared to conventional ASP.
 
In this study, performance of a full-scale combined treatment plant for oilfield wastewater from alkaline/surfactant/polymer flooding was investigated. The combined process consisted of chemical coagulation, hydrolysis/acidification, and bio-contact oxidation. The experimental results demonstrated that chemical coagulation treatment with polymeric ferric sulfate proved to be the most effective in removing the chemical oxygen demand (>80%) from the wastewater under the dosage of 600 mg/m3. The highest acidification efficiency in hydrolysis acidification tank was 25.8% at hydraulic retention time of 20 h. The average values of chemical oxygen demand, biochemical oxygen demand, oil, and NH3-N of the combined process could be reduced to 116, 19, 4, 11, and 20 mg/L, respectively. The final effluent could meet the class II national wastewater discharge standard of petrochemical industry of China.
 
The authors have statistically analyzed the relationship between the distributions of n-alkanes in diesels and the response of the diesel flow improver (DFI) to explore the reasons for the performance variation of DFIs. Diesel with a small n-alkane distribution variance showed a weak sensitivity to the DFI. The wax settling levels of the diesels were calculated at low temperature using a thermodynamic model and were found to increase as the n-alkane distribution variance decreased. Higher levels of settled crystals led to the poor performance of the DFI in the diesel with a small n-alkane distribution variance.
 
Heavy alkyl benzene (HAB) is a byproduct in the process of linear alkyl benzene (LAB) production. It is used as heat transfer oil and lubricating greases. In this article the potential of the usage of HAB in the formulation of gasoline and diesel engine oils as well as hydraulic fluid is indicated. With the aim of passing 5W30, 5W40, 10W40, and 15W40 standards, different engine oils have been formulated. The formulations contain various amounts of HAB as minor component, and miscellaneous quantities of solvent neutral 100 (SN-100), SN-150, and SN-650 as major component. The measurement of typical properties of obtained oils indicates that some of them do have the intended criteria. Test field of the recent oils designate that they have good performance. In the next step, different blends of HAB as major component and polyisobutene (PIB) as minor component have successfully been employed in the formulation of several ISO grade hydraulic fluids. The achieved materials do have suitable air release and demulsibility.
 
The foamability (solid line, left vertical axes) and foam stability (dashed line, right vertical axes) in AOS (a) and TX100 (b) surfactants in aqueous CO 2 system.
Normalize foam height of AOS-TX100 (2:8) (a), AOS-TX100 (5:5) (b), and AOS-TX100 (8:2) (c) solutions at different concentration.
The foamability (solid line, left vertical axes) and foam stability (dashed line, right vertical axes) in AOS-TX100 (2:8) (a), AOS-TX100 (2:8) (b), and AOS-TX100 (2:8) (c) surfactants in aqueous CO 2 system.
Synergistic effect in mixed anionic and nonionic surfactants.
Polar chart compare the surface tension variation among the single and mixed surfactants.
Foaming behavior is an important consideration in the design of many foam-based operations and processes. The foam behavior and synergistic effect of aqueous CO2 by the single anionic surfactant alpha olefin sulfonate (AOS), nonionic single surfactant Triton X-100 (TX100), and mixed surfactant solution (AOS-TX100) with varying concentrations were investigated in detail. The role of each surfactant and mixed surfactant solutions were analyzed in view of the foamability, foam stability, and synergistic effect after equilibrium of aqueous CO2 foam. It was found that AOS and the composite surfactant AOS-TX100 (8:2) had better foaming behavior than any single surfactant and mixed surfactants.
 
Foam behavior and synergistic effect of aqueous CO2 by three different sizes of hydrophobic silica nanoparticles with varying concentrations in presence of single anionic surfactant alpha olefin sulphonate with constant concentration of 1000 ppm were investigated in detail. The role of each size of silica nanoparticle was analyzed in view of the foamability, foam stability, and synergistic effect after equilibrium of aqueous CO2 foam. Result reveals that the bigger size of silica nanoparticle has better effect in low concentration and generally smaller size of silica nanoparticle has better influence on CO2 foam stability at higher concentrations.
 
Gas well productivity is affected by liquid blockage of the wellbore region, and if the wettability of porous media shifts to gas-wetting, then deliverability in gas condensate reservoirs will increase. In this article, a sol-gel process and modification of perfluoroalkyl methacrylic copolymer (Zonyl[Inline formula] 8740) were employed to alter the wettability of rock core surfaces. Contact angle analysis and a spontaneous imbibition test suggested that wettability of the core could be altered to gas-wetting by sol-gel deposition and treatment with Zonyl 8740. Consequently, the rough surfaces made by sol-gel, which were modified by Zonyl 8740, resulted in wettability reversal to gas-wetting of porous media.
 
BET Surface Area and BJH Desorption Average Pore Diameter of the Fresh and Spent Forms of Cu/Ca (10:90)/Al 2 O 3
The presence of naphthenic acids in crude oils has caused a major corrosion problem to the production equipment, storage and transport facilities in the petroleum industry. To overcome this problem, catalytic neutralization method will be investigated on real petroleum crude oil sample with various parameters study such as the type of basic chemical used, dosing amount, type of catalyst, catalyst calcination temperature, and catalyst ratio of basic metal and dopant. Potential catalyst was characterized by XRD, NA, and TGA-DTA for its physical properties. Cu/Ca(10:90)/Al2O3 catalyst with calcination temperature of 1000°C was an effective catalyst for all three types of crude oil. In the presence of catalyst, all three types of crude oil samples showed enhancement in the removal of naphthenic acid.
 
This work presents an experimental and theoretical investigation of CO2 absorption into aqueous of 2-amino-2-methyl-1-propanol (AMP). The solubility of CO2 in AMP solution has been measured at temperature range of 293, 303, 313, and 323 K. The amine concentration ranges studied are 2.0, 2.8, and 3.4 M. A solubility apparatus was used to measure the solubility of CO2 in AMP solution on samples of flue gases from thermal and central power plants of Esfahan Steel Company. The Deshmakh-Mather model was used to correlate and predict the vapor-liquid equilibria of the (CO2 + AMP + H2O) system. Data on CO2 loading in aqueous solutions of AMP were fitted to generate the different interaction parameters required to calculate the activity coefficients in the model. The model predicted results are in good agreement with the experimental vapor-liquid equilibrium measurements.
 
Potential source rocks west of the central Anatolia basin, in Beydili/Nallıhan (Turkey) include Paleocene-Eocene oil shale. Organic geochemical analyses show that the organic components in oil shale are of mainly algal-amorphous organic matter, indicating that they are marine (mainly type I–II kerogen). The organic carbon content of Beydili rocks ranges from 1.35 to 11.12 wt%, Göksarlık Tepe rocks 1.06 to 13.8 wt%, and Kepeztepe rocks 1.55 to 11.31 wt% They have source rock quality for oil generation. The Paleocene-Eocene oil shale is in the early stage of oil generation. The redox conditions of depositional environment in three different areas have a transition period from oxic to anoxic.
 
Hydrogenation of maleic anhydride (MA) to succinic anhydride (SA) over Ni-Pd bimetallic catalysts prepared by impregnation method has been studied at different Pd contents, pressures and temperatures. Catalytic activity was greatly influenced by the Pd content, pressure and temperature. Use of 5wt%Ni-0.02wt%Pd/clay catalyst, the 100% conversion for MA and 100% selectivity for SA were obtained for MA hydrogenation at normal pressure. The catalysts were characterized by an array of techniques, including X-ray diffraction (XRD) and H2 temperature-programmed reduction (TPR). XRD and TPR studies showed that nickel was present as Ni2+ species on the support, and that there was no elemental nickel (Ni0) and Ni2O3 in the unreduced samples. XRD and TPR also showed that Pd was as amorphous existence on the catalysts.
 
Surfactant flooding is an amazing approach which is a subgroup of enhanced oil recovery approaches. Two phenomena which are involved in oil recovery with the aim of surfactant are wettability alteration and interfacial tension reduction between oil and water phases. Reservoir fluid contains a mixture of some slats which have a major effect on surfactant properties. Also the temperature in the reservoirs affects the surfactant flooding condition. Salinity and temperature play a vital role in the performance, effectiveness and successfulness of the surfactant flooding which highly affect on critical micelle concentration (CMC) of the used surfactant. Put another way, the CMC of the surfactant depends on the salinity and temperature of the solution. The goal of this study is figuring out the CMC of alkylebenzene sulfonic acid (ABSA) in various conditions which include different potassium chloride concentrations and various temperatures; this was done by the conductivity method. The CMC value of ABSA as an anionic surfactant was gained with the aim of electrical conductivity approach. Thanks to the experimental results of this article, the CMC of the ABSA is highly dependent on the KCl concentration which is reduced by increasing the KCl content of the solution. On the other hand, the CMC of ABSA slightly depends on the magnitude of the temperature which varied from 25°C to 70°C with increments of 5°C. Finally, CMC value of the aforementioned surfactant increased versus increasing the temperature of the solution.
 
Topographic map with distribution of gravity stations and aeromagnetic data.
Regional geological map with structure units in the northern area of Eastern Xinjiang.
The correlation coefficient map with (A) regional gravity anomaly and (B) regional magnetic anomaly at a corresponding scale of 70 km. (Correlation coefficients were calculated between regional gravity and magnetic anomalies with a filter at a geometric scale of 70 km).
The authors discuss the genesis of the regional gravity and magnetic anomalies in the northern part of Eastern Xinjiang, a correlation analysis was carried out between the regional gravity anomaly and the regional magnetic anomaly. Through data processing and integrated interpretation of the gravity and magnetic data in the study area, the Bouguer gravity anomaly and the magnetic anomaly by reduction to the pole were separated. Then, the regional gravity and magnetic anomalies across multiple scales were extracted; in addition, the correlation coefficients between the regional gravity anomaly and the regional magnetic anomaly at different scales were calculated. Finally, the features of the gravity and magnetic fields, their geological significance, and the origins of these regional gravity and magnetic anomalies were analyzed. The results showed that the regional negative gravity anomaly in the Turpan-Hami basin and the Santanghu basin was mainly caused by Cenozoic and Mesozoic strata; the regional positive magnetic anomaly was mainly caused by the Precambrian metamorphic basement. The study revealed that the regional positive gravity and magnetic anomalies resulted from the crust and the mantle substances in the eastern part of the Junggar basin. While the regional positive gravity anomaly was mainly caused by Pre-Mesozoic strata, and the regional negative magnetic anomaly by the sedimentary formation and intermediate acid rocks in the Bogeda-Harlike folded zone and the Jueluotage anticlinorium. The regional negative gravity and magnetic anomalies in the active zone of the northern margin of Tarim were mainly caused by the sedimentary formation and intermediate acid rocks.
 
The classical Apriori algorithm model for predicting yields of Huabei liquefied petroleum gas have been introduced based on Visual FoxPro software in the present article. The experimental results show that the classical Apriori algorithm model can predict yields of Huabei liquefied petroleum gas and the experimental data are in agreement with the quantitative analytic conclusions drawn from the predicted data. This proves that it can be used to predict yields of Huabei liquefied petroleum gas. It results in good economic and social benefits for Chinese chemical plant.
 
The commercial Co-based Fischer-Tropsch catalyst and HZSM-5 were tested in a single reactor process. FT catalyst was evaluated at 463 K, whereas HZSM-5 was evaluated at various temperatures (523, 573, and 623 K). The effect of syngas flow rate, HZSM-5 temperature and loading on liquefied petroleum gas (LPG) and aromatics selectivities were investigated. HZSM-5 addition suppressed the formation of CO2 and CH4, and remarkably enhanced the simultaneous formation of LPG and aromatics. The optimal operating conditions were identified as: THZM-5 = 623 K, HZSM-5 loading = 2.5 g, and GHSV = 4.8 Lsyngas/(gcat h).
 
By using Lanlian catalytic gasoline aromatization production as a feedstock, the effects of reaction conditions on the aromatization product yield, conversion, motor octane number (MON), research octane number (RON), and solvent product compound were researched in a confined fluidized bed reactor. The experimental results show that the changeable trend of secondary aromatization yield of Lanlian FCC gasoline are the same with FCC gasolines under the operation condition. Although the aromatics contents of FCC gasoline after the secondary aromatization are about 5%, MON value of production decreases and RON value of production remain no change and coke yield contents are very high. These show that the qualities of secondary aromatization of FCC gasoline are very poor.
 
The Khesht field was discovered in 1992 and located some 25 km from Kazeron town. One reservoir (Asmari) was found to be hydrocarbon bearing in the field. The discovery well also tested to a production rate of 9,450 barrels of oil per day. Artificial lift method selection is very important. An improper selection of artificial lift can reduce production and increase the operating cost substantially. Once a decision has been made on the type to install on a well, it can be rarely altered whether or not the method selected was and still is the optimal for the existing conditions. The authors present the screening criteria on the different artificial lift techniques and discuss among them to choices suitable technique to apply in the field. A comparison among natural flow, electrical submersible pump, and gas lift will present for the Khesht field only to help in reaching the conclusions to verify the best solution to produce the wells. In this study the production rates are the only factor in determining the best well completion. Reservoir simulation model was used to predict the performance of different artificial lift methods.
 
The interaction of fly ash (FA) on dichlorocarbene modified styrene butadiene rubber (DCSBR) is evaluated with reference to their flame and oil resistance. Flame and oil resistance of the composite increased progressively with increasing filler content in DCSBR. The barrier properties of these composites are examined in an atmosphere of petrol, diesel and kerosene. The solvent uptake nature of composite is found to be much reduced. The solvent uptake is minimum for composites with 30 phr filler and increased with increasing filler content, which is presumably due to aggregation of filler at higher loading; activation parameters are also estimated.
 
Modified asphalt binders with varying Xinjiang asphaltite contents between 4% and 16% were prepared in laboratory. Dynamic shear rheometer temperature sweep and time sweep tests, bending beam rheometer tests, some conventional tests including penetration and softening point were performed to analyze the rheological properties of these asphalt binders and evaluate Xinjiang asphaltite potential as asphalt modifier. Test results showed with the Xinjiang asphaltite content increasing, complex shear modulus increased and phase angle decreased, which indicated Xinjiang asphaltite could improve the elasticity and deformation resisting of binders. Fatigue failure life of asphalt binders grew exponentially with Xinjiang asphaltite content. Moreover, Xinjiang asphaltite had an adverse effect on the low temperature performances of asphalt binders based on measured creep stiffness and m-value. Based on these test results modification mechanism of Xinjiang asphaltite was analyzed. It is thus suggested that Xinjiang asphaltite is better suitable as a high temperature resistant and anti-fatigue asphalt modifier material.
 
This work aims at evaluating the effects of the proportions of crumb rubber and shale-oil residue on the fatigue parameter G*sinδ. Eight asphalt binders were submitted to short- and long-term aging and then tests in the oscillatory-shear mode were performed. Based on regression models, response trace plots, and contour plots were made. Both rubber and oil reduce the G*sinδ parameter, increasing the controlled-mode fatigue resistance. As the test temperature decreases, the intensity of the effects of rubber and oil on G*sinδ increases and the number of mixtures that meet the Superpave limit of 5.0 MPa reduces.
 
Top-cited authors
Simon Ivar Andersen
Ravikanth S Vajjha
Debendra K. Das
  • University of Alaska Fairbanks
Miguel Orea
  • Central University of Venezuela
Mohammad Hossein Ghazanfari
  • Sharif University of Technology