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Beside their worldwide abundance, oil recovery from fractured carbonate reservoirs is commonly low. Such reservoirs are usually oil-wet, thus, waterflooding leads into early breakthrough and low recovery due to the high conductivity of the fracture network, negative capillary pressure of the matrix and, consequently, the poor spontaneous imbibitions of water from fractures into the matrix during the course of waterflooding. In such problematic reservoirs, changing the wettability of the matrix toward water-wetness can improve spontaneous imbibition by changing the sign and, thus, the direction of capillary forces, resulting in an improvement of waterflood efficiency and, consequently, oil... 

Several corrosion inhibitors, such as, HEDP, sodium molybdate and zinc ions, were added to an aqueous corrosive media containing different concentrations chloride ions, and the corrosion rates (CRs) of carbon steel were measured at various temperatures. It was shown that, in the presence of more than 1,200 ppm of chloride ions, and temperatures greater than or equal to 42.5°C, the combination of HEDP, molybdate and zinc could not control the corrosion in a cooling water system. Then four different models were designed to represent the CR of carbon steel in presence of various corrosive parameters  

Gas injection into reservoirs can be used to increase oil recovery. However, reservoir heterogeneity and high gas mobility reduce sweep efficiency and decrease recovery. Using foam can reduce gas mobility and therefore increase sweep efficiency. Foam is thermodynamically unstable, so it is important to predict the foam stability. In order to understand the influence of oil presence on foam stability, static experiments performed on foam by varying the type and amount of added oil and molecular weight of added alkane. Also static foam properties have been investigated by varying the surfactant concentration, ionic strength, composition of different salts in the sample, and addition of polymer... 

Power generation consumes a substantial amount of water in the power industry. In order to address the impact of water consumption restriction on the power generation, this paper proposes a security-constrained unit commitment (SCUC) formulation considering water consumption impact as an additional constraint. To this end, the water consumption in power plants is formulated. Consequently, the SCUC is extended to consider the consumed water volume as a restricting factor. A procedure is introduced to investigate the most appropriate point of power generation operation to save a vital amount of water by raising reasonable generation costs. The objective of the proposed model is to minimize the... 

The deactivation of solid acid catalysts in liquid-phase alkylation of isobutane with butenes was investigated. The role of pore mouth plugging, in particular, was studied and it was found that it had a significant effect on the deactivation behavior. Simple explicit correlations were developed for catalyst lifetime in a CSTR, both in terms of time-on-stream and butene turnover per catalyst weight. The correlations were tested using available experimental data from the literature and a reasonable agreement was observed. It was shown that for a zeolitic catalyst the butene turnover per catalyst weight was proportional to the square root of catalyst loading, while it was inversely proportional... 

Dimensional analysis of the governing equations in liquid-phase, solid-acid-catalyzed alkylation was used to develop an empirical model for the catalyst lifetime in terms of important operating variables. It was found that the dimensionless catalyst lifetime in a continuous stirred tank reactor was a function of four dimensionless groups, incorporating all important kinetic and operating variables. A power-law correlation was found to be adequate in representing the available experimental data. Because the alkylation reactions are highly diffusion-limited, it was shown that only three of the four exponents in the power-law correlation were independent. As such, the fourth exponent was... 

The differential form of the decay law for a solid acid catalyst in liquid-phase alkylation of isobutane with butenes was investigated. A pseudo-first order expression for the intrinsic rate of the main reaction and a pseudo-second order one for the poisoning reaction were assumed. The role of intraparticle diffusion on the apparent deactivation behavior was studied through the Shell Progressive Model (SPM), as the overall reaction is severely diffusion limited. The decay rate law was found to be fourth order in pellet activity and second order in external butene concentration. The effect of pore-mouth plugging was also studied. It was shown that this phenomenon causes an increased deviation... 

This paper studies a WAG process for improving the recovery efficiency in light oil reservoirs. Until now, few references have reported the role of CO2 mole percent on recovery improvement in light oil reservoirs. The injected gas was changed, and the effect of composition changes on performance of core flood experiments were conducted at fixed flow rate. Five series of experiments (varied in methane mole percentages, 0, 25, 50, and 75, 100) were systematically examined. The results indicated that the oil recovery efficiency improved with the increasing of CO2 mole ratio and there was also maximum recovery efficiency in this work. That would be helpful to better understanding the role of CO2... 

In this paper, thermal and catalytic hydrocracking of liquid paraffin hydrocarbons, from Tehran refinery, is studied using a pilot plant reactor. The experimental system consisted of a vertical tubular flow reactor where hydrogen and liquid products were fed from the top of the reactor and after passing through a bed of catalyst (or quartz beads in the case of thermal hydrocracking experiments), the liquid and gaseous products were separated and sampled for subsequent analyses. The reaction temperature was in the range of 410-430°C for catalytic hydrocracking and 440-470°C for thermal hydrocracking experiments. The space velocities for both sets of experiments varied between 0.5 to 1.5... 

A new and general procedure for history matching that uses streamline simulation and a gradual deformation technique has been proposed. Streamline trajectories define the major flow paths and help the algorithm to modify the reservoir model only in the regions that cause the mismatch between simulation results and field observations. The use of a gradual deformation technique enables the algorithm to remain constrained to reservoir geostatistics. It also reduces the number of independent variables in the optimization problem. In our algorithm, effective conductivities are defined along each streamline. The effective streamline conductivities are then adjusted using the values of measured and... 

Exhaust gas emissions from mobile sources and its importance in urban pollution have currently attracted lots of interests towards studying on alternative fuel systems for road vehicles usage. One of the best replacements is the natural gas/diesel dual fuel, which offers an alternative to standard compression-ignition diesel engines. In the dual fuel system the primary fuel is natural gas, which may replace as much as 90% of the diesel fuel with a small amount of diesel fuel required ensuring effective ignition. Methane, the main constituent of natural gas, has high combustion efficiency. Dual fuel engines produce lower NOx emissions and fewer particulates. However, at moderate engine loads,... 

This paper presents a formulation of fuzzy optimization for uncertainties in natural gas in fuel constraints for hourly individual unit and total unit fuel consumptions. Security Constrained Unit Commitment (SCUC) is usually a mixed integer programming and gas load flow has a non-linear equation a genetic algorithm is proposed to solve natural gas transmission network. A fuzzy mixed integer programming optimization is briefly discussed and adapted to deal with security constrained unit commitment schedule. Finally, two case studies are investigated (IEEE 6-bus system with 7-node natural gas transmission grid and the IEEE 118-bus power system linked with 14-node gas transmission test system)... 

Ti4Ni2O, Ti4Ni2N, TiC and Ti2Ni are brittle compounds usually formed during production and processing of the Ti-Ni SMA alloys. These compounds adversely affect on workability and shape memory properties of the alloy. This paper presents most recent findings related to the morphologies of various inclusions and Ti-Ni phases formed during and after vacuum induction melting and casting of Ti-45wt.% Ni material. Cast samples were mechanically and/or electrolytically polished and etched. Extensive optical and scanning electron microscopic studies were carried out to characterize the composition and microstructure of the as cast Ti-Ni alloys. Results indicated that mechanical polishing followed by... 

The concentration distribution and microstructure of NiTi shape memory alloys produced in vacuum induction furnaces operating at high and medium frequencies are compared with those of materials melted in vacuum resistance furnaces. The production procedure consisted of charging pure metals into a graphite crucible; raising the temperature to 1450°C under vacuum; holding the materials in high and medium frequency induction and resistance furnaces for 3, 5, and 120 min under vacuum; and allowing alloys to solidify in the crucibles under the same vacuum. The procedures in each of the three furnaces were made as similar as possible. Chemical composition, microstructure, and surface hardness of... 

Using natural gas combined with diesel fuel in diesel engines provides a considerable contribution to modern industrial societies in order to control air pollution and, also, generalize and facilitate the use of public vehicles. In spite of the attractive features of this idea, including reduction of NO(X) and particulates, there is an important burden imposed upon the system at low to intermediate torques, namely high concentration of CO and unburned total hydrocarbons (THC), mostly composed of methane. In this work, based upon the oxidation of CO and unburned HCs and through experimental results, application of a monolithic oxidizing bifunctional catalytic converter as a novel... 

There is a global tendency towards using Distributed Generation (DG) and renewable energy resources. Considering low utilization cost and low undesirable environmental effects, wind farms have become a considerable resource for producing electrical energy in many countries. Since Wind farms are not programmable and their power output which depends on weather and wind speed is uncertain, they create problems for utilizing electricity system. There are different methods for preserving system stability against the uncertainty of wind power plants. Optimal utilization of pumped storage and gas resources is one of the approaches for reducing production risk of wind farms. In this paper, it is... 

Reduction of aromatics implies that the gasoline pool would suffer both quantitatively and qualitatively. Alkylates (highly branched paraffinic hydrocarbons) are ideal substitutes because of their high octane numbers, and environmental friendly characters. Alkylates have played significant roles in US gasoline pool, while in Europe alkylates have a lesser important role. The phase out of lead and the increased capacity of FCC units for making more gasoline from heavier petroleum cuts have enhanced the validity of alkylation processes in petroleum refineries. Based on the data obtained in the laboratory using a new developed catalyst, it is predicted to behave as a successful catalyst for C4...