PETROLEUM RESEARCH
Year:2017 | Volume:27 | Issue:93 |Papers Count:21

The most important source intervals through Cretaceous to Tertiary succession in the Zagros basin which generated most of the oil and gas in the Cretaceous reservoirs include Garau, Gadvan, Kazhdumi and Pabdeh formations. In this study, the Tertiary Pabdeh and Early Cretaceous Kazhdumi formations were geochemically investigated. More than 87 core and cutting samples were collected from 22 exploration wells of 13 oil fields in the Abadan Plain, south-west of Iran. After required preparations, samples were subjected to Rock-Eval pyrolysis and organic petrography in order to measure their generation potential and thermal maturity levels. The results showed that Pabdeh Formation with an average TOC of %1.25 and average HI of 145 mg HC/g TOC can be regarded as fair to good source rock, whereas Kazhdumi Formation with average TOC and HI values of %1.8 and 278 mg HC/g TOC, respectively, is found to be a good to very good source rock. Maturity indicator parameters; such as, Tmax and vitrinite reflectance indicated an immature stage for the Pabdeh Formation in the Abadan Plain. However, the maturity levels for the Kazhdumi Formation range from immature level in the western part of the study area to the beginning of the oil window in the eastern part and in the vicinity of the Dezful Embayment. The iso TOC map and the Tmax maps of Pabdeh and Kazhdumi formations in the studied area revealed an eastward increasing trend for the production potential and organic matter maturity toward the Dezful Embayment.

In this research, the adsorption of sulfur compounds from propane and butane streams (real gas from Assaluyeh) using faujasite-type zeolite in constant pressure and temperature was studied. Zeolite NaY was synthesized in order to specify the effect of NaY size on adsorption of sulfur compounds. The synthesized samples were characterized by XRD, FE-SEM and BET analyses then three different sizes of NaY zeolite (60nm, 800nm, 2400nm) were selected to specify the effect of the particle size on the sulfur compound’s removal performance. The outlet gas streams were characterized using a potentiometric method (UOP212). Breakthrough curves were plotted for each stream; moreover, the breakthrough curves were modeled using BDST (bed depth service time) model and Yoon-Nelson model in order to determine the effect of adsorbent’s size, type of inlet gas and the amount of sulfur compounds on the parameters of Yoon-Nelson and BDST models. After making a comparison between the results from breakthrough modeling, it was concluded that for BDST model, decreasing the size of NaY zeolite increased the adsorption capacity index while the proportionally constant model was being decreased; however, in Yoon-Nelson model, decreasing the size of NaY zeolite increased time to %50 of breakthrough curve and decreased the proportionally constant model.

In many explored gas reservoirs in the word, which are considered as gas-gas condensate reservoirs, many surface facilities receive the gas as well as hydrocarbon condensates and water. Condensates cause slugs in a pipeline. The slugs, which are an aggregate of fluids, cause many problems in multiphase pipelines. Therefore, in order to separate condensates, slug catchers are normally used. A slug catcher is necessary equipment at the entry of a multi-phase flow processing factory. The specific performance of a slug catcher is the separation of gas and liquid phases and temporary storage of the liquids. In this paper, we recommend a method for designing finger type slug catchers, based on two phase flow in principles. Then, using the proposed method, we design a slug catcher for the two present phases in the South Pars gas field. At the end, by considering condensate recovery and economical investigation of the suggested slug catchers, we choose the optimum slug catcher for these two phases. Among the most important results of this investigation, we can mention an efficient pattern for designing finger type slug catchers and the selection of the optimum one. Using this pattern is recommended for a proper design and reduction of time and costs.

Hydrogen evolution via water splitting was investigated over the son ochemically synthesized TiO-2clinoptilolite photo catalysts with the aim of assessing the effect of ultrasonic irradiation during the impregnation procedure employing for TiO2 deposition. To this aim, photo catalysts containing 10wt% titania were prepared by an impregnation method in the presence and absence of ultrasound irradiation. The samples were characterized by XRD, FESEM, EDX, BET, FTIR, PL and UV-vis techniques. The characterization results indicated that ultrasound irradiation endowed the photo catalysts with uniform morphology, higher surface area and more homogenous dispersion. In addition, the analyses also exhibited less population of particle aggregates, a strong titania-support interaction and a lower electron-hole pair recombination rate. The high photo catalytic activity, 502.29, mmol/gTio2.h was obtained for TiO2/Clinoptilolite photo catalyst prepared by the ultrasound assisted the impregnation method (TiO2/CLT (UI)), which was about 7 times more than that of bare TiO2. Furthermore, TiO2/CLT (UI) photo catalyst showed sufficient reusability, making it a good choice for photo catalytic water splitting applications.

One of the challenges of the exploitation and production of oil from reservoirs is the deposition of asphaltene particles on the transfer surfaces; such as, porous media, wells and piplines. Knowing about the particle size of asphaltene, in the studies of solid mass transfer of fluid to the surface, is essential to estimate the location, amount and time of the scale. One of the questions wich has been studied less is «How do the sizes of asphaltene particles change at different thermodynamic conditions? » In this study, asphaltene instability in one of the iranian heavy oil was determined by SARA test, initially. Thermodynamic behavior of asphaltene was found through filtration tests in high pressure and temperature conditions. Then, using an optical microscope, the sizes and distributions of the asphaltene particles were measured at 12 temperature and pressure points. The experimental results showed that both particle sizes and distribution of particles are sensitive to temperature and pressure. The thermodynamic and microscopic results are matched appropriately. Finally, the obtained experimental results were modeled in the form of an empirical correlation. The results of this study could be as an integrated chain between thermodynamic behavior of the asphaltene and the transfer phenomena of the asphaltene deposition in the oil well column and reservoir porous media.

Carbon dioxide is a greenhouse gas that has the most effect in the phenomenon of global warming. Carbon dioxide capture and storage are considered to be a top choice for reducing greenhouse gases in the atmosphere. Saline aquifers have high potential compared with other storage options, such as, depleted oil and gas reservoirs to store Carbon dioxide. In the last decade, there has been a great interest in the study of storing Carbon dioxide in the saline aquifers. Among the different mechanisms, Carbon dioxide can traped in the aquifer by dissolving in water. Water evaporation is a process that leads to salt deposition in the surrounding area of the injection well that reduces the porosity, damages the reservoir permeability near the wellbore and reduces the well injectivity. Modeling and the simulation have been performed by MATLAB R2013a software to study the effect of Carbon dioxide injection on the aquifer properties. A comparison between the results and those obtained using Zeidouni et al. shows that the proposed model has the same values for porosity change and permeability reduction. The proposed model with an average relative deviation about %7 is able to accurately predict the aquifer properties during CO2 gas injection.

The goal of this paper is to optimize Alkylation unit based on industrial data in order to maximize the production rate as well as keeping operational condition of the unit at the desired values. The input variables of alkylation unit are usually input feeds, and output variables are products (i.e. alkylate, normal butane and propane), acid consumption, alkylate octane number, reflux flow of isobutene to reactor and isobutene to olefin ratio in the reactor. Based on industrial data of alkylation unit, the mathematical process model has been obtained using response surface method (RSM). The method has a dominated application in numerous areas of research particularly in chemical process industries. The accuracy of the proposed method has been validated using an analysis of variance (ANOVA). Finally, the optimization of operational condition for an alkylation unit has been carried out using Design Expert 7.

Cupronickel 90-10 is one of the most applicable Cu-based alloys which possess suitable corrosion resistance and strength and is employed extensively in marine industries particularly in the boilers and heat exchangers. Generally, the tubes of water cooling systems especially those use seawater as cooling medium are made of this alloy. In this paper, the causes of premature failure of a cupronickel (90-10) condenser tube used in a cooling system of an oil refinery in the south of Iran have been studied by different microscopical and analytical methods, e.g. X-ray fluorescence spectroscopy (XRF) and X-ray diffraction (XRD). The results showed that pitting corrosion on the internal surface of the tube was the main cause of its failure which was a consequence of the stagnant of the tube by external solids and preparation of an appropriate environment for the activity of microorganisms, hence, microbial corrosion.

Among various methods available for chemical enhanced oil recovery, alkaline injection has great potential for production of heavy acidic crudes from oil reservoirs. Through the reaction with acidic components of crude oil, caustic solution reduces the interfacial tension of different existing phases which leads to higher oil production. Besides, asphaltene deposition is a major problem during the production and exploitation from heavy oil reservoirs. The inhibition of asphaltene deposition and proposing a suitable amendatory solution in case of deposition occurrence are significantly important. In this study, the efficiency of alkaline injection on the recovery of crude and synthetic oil solutions was investigated using two different glass micro models, (i.e. homogeneous and heterogeneous). Furthermore, the effect of alkaline injection in the case of the presence of precipitated asphaltene due to heptane injection was visually observed. Experimental results showed that in crude oils and synthetic solutions, whenever no asphaltene was precipitated, alkaline injection was effective but after asphaltene precipitation, alkaline injection did not have any considerable impacts on oil recovery. The results also demonstrated and authenticated that alkali flooding can alter micro model wettability in some parts of the model. This wettability alteration mechanism eventually results on enhanced oil recovery.

Blend membranes based on the poly (ether-b-amide) and vinyl acetate/ dibutyl maleate copolymer were prepared via solution casting. Results of the gas permeability test showed that the selectivity of carbon dioxide gas (CO2) relative to the methane (CH4) gas in the prepared membranes increases twofold while the permeability of these gases decreases by increasing amount of vinyl acetate/ dibutyl maleate copolymer. Diffusivity and solubility of CO2 in the membranes were calculated, and it was found that decrease in permeability is due to the decrease in the diffusivity of gases in the blend membranes. To further understand this issue, fractional free volumes (FFV) of the membranes were calculated by two different methods, one without and another with considering the permeated gas from membrane. It was observed that by increasing the amount of the vinyl acetate/ dibutyl maleate copolymer in the blend membranes, FFV decreases. By equations at hand for polymers, a relationship between the FFV of membranes and diffusivity and permeability of the gases was established, and a good correlation between them was found.

This paper presents the feasibility (or possibility) of removal of asphaltenes from aqueous solutions by using low-cost natural adsorbents; such as, light expanded clay aggregate (LECA), perlite and bentonite. The effect of adsorbent type, initial asphaltene concentration, particle size of adsorbent and temperature on the adsorption capacity was investigated. The results showed that at the initial asphaltene concentration of 125 mg L1-, contact time of 24 hrs, temperature of °50C and adsorbent dosage of 1 g, removal of asphaltenes onto LECA, perlite and bentonite was 53.59, 93.01 and %99.77, respectively. Also, Langmuir and Freundlich models were applied to describe the experimental data; moreover, the results indicated a good fitting by Langmuir isotherm. Thermodynamic parameters; such as, DH, DS and DG were calculated. It was revealed that the adsorption was spontaneous and exothermic nature, which was evident by decreasing the randomness of the dye at the solid and liquid interfaces. The characteristic results and the dimensionless separation factor (RL) showed that perlite and bentonite could be employed as an alternative to commercial adsorbents in the removal of asphaltenes from aqueous solution and oil.

The use of Biogas as a feed for dry reforming of methane has many environmental and economical advantages. Despite the high activity and low cost of Ni/Al2O3 catalyst, it shows pour stability due to coke deposition and active phase sintering. In this study, the effect of the synthesis method (impregnation vs. sol-gel) was evaluated on (1) physicochemical properties, (2) activity and (3) stability of Ni/Al2O3 catalyst. Extraction of physicochemical properties of nano catalysts by XRD, FESEM, FTIR, BET, PSD and TG-DTG showed that the sol-gel method produced amorphous phases, uniform nanoparticles´ distribution and a higher surface area in comparison with impregnation method. FTIR analysis confirmed the existence of desired functional groups and lack of spinel compounds which were in agreement with XRD analysis. PSD analysis (<60 nm) demonstrated the promotion of Ni/Al2O3 catalyst by sol-gel method synthesis. Therefore, it can be found that preparation method had a great influence on physicochemical properties of catalyst; such as, crystallinity, surface area and morphology. The performances of catalysts were evaluated at atmospheric pressure, feed gas ratio of CO2/CH4=1, GHSV=24 l/g.h and temperature ranges from 550 to 850°C. The stability test also was performed at °850C for 24 h. The results revealed that the synthesized catalyst by sol-gel method had better performances. The excellent syngas ratio (0.99) had been produced only by sol-gel synthesized Ni/Al2O3 nano catalyst; besides, its activity loss was less than the nano catalyst synthesized using impregnation method.

Induction time and the amount of gas consumed, two important kinetic parameters in gas hydrate formation process, were investigated for the systems of water + methane and water + TBAC + methane, in this research. In order to study the effect of TBAC on the kinetics of methane hydrate formation, three aqueous solutions of TBAC with concentrations of (0, 3, and 5) wt% were prepared. The experiments were carried out (or done) in a 169 cm3 batch reactor and at a temperature of 278.15 K and initial pressures of (6.5 and 8) MPa. The results showed that adding TBAC decreases the induction time of hydrate formation process. The utilization of TBAC with concentration of 3 wt% at 8 MPa decreases the induction time from 437 min to 3 min and increases the amount of gas consumed during hydrate formation %47.09, compared to pure water. The experimental results showed that by increasing the pressure form 6.5 MPa to 8 MPa, the induction time of methane hydrate formation decreases, and the amount of methane consumed increases. In addition, by increasing the pressure form 6.5 MPa to 8 MPa in aqueous solution of TBAC with concentration of 3 wt%, the induction time decreases from 41 min to 4.12 min and the amount of methane consumed increases from 20.98 mmol/mol of solution to 28.29 mmol/mol of solution.

In this research, an integrated model to provide both pure and mixed viscosity hydrocarbons in areas; such as, supercritical gas and liquid using only one equation of state (Peng and Robinson) is provided. The main idea of this method is based on the similarity between data and theory TmP, PVT and balance. In this modeling, the constants of the viscosity state’s equation are calculated from a similarity between diagrams of PVT and TmP at the critical turning point. The equation of R constant viscosity (similar to universal gas constant parameter) is calculated from the dependence on the pressure in critical situations. In the model proposed by Fan Wang (the same model), critical compressibility factor values for each variable were reported. In this study, for the purpose of simplicity and better performance, a given amount (Zc=0.3074) has been provided for this coefficient (index). Finally, a statistical objective function has been used for the purpose of making a comparison between the model’s performance and the experimental data. So that the mean absolute error for the mixture of heavy and light compounds by using modeling on 122 experimental data as well as for the purpose of extending the model to a mixture of two, three, four and five which for the thermal limitation based on Kelvin and the pressure’s limitation based on Bar for the compounds of three at the limitation of pressure (3.08 to 6.35), thermal (324.26 to 395.37); for the compounds of four at the limitation of pressure (2.73 to 4.12), thermal (359.82 to 395.37); for the compounds of four with Carbon dioxide at the limitation of pressure (25.14 to 48.28), thermal (324.26 to 395.37) and the incorporation of the new rules for more accurate modeling is used. Based on PRμ0 model, the calculated liquid viscosity has had less accuracy, so that by generating the optimization parameters in PRμ0 equation, deviation calculations will be reduced. Moreover, the average error rate for each of these mixtures is 5.04, 3.21, 5.16 and 2.9 percent recpectively, which is more accurate than the Wang technology for predicting the behavior of this mixture.

The permanent problems in production of oil and gas are water conning and water production. If one well is affected by this phenomenon, hydrocarbon production will be decreased and related costs will be increased. Researches prove that for any scenarios in production or development of a field, investigating the reservoir parameters is very indispensable (or necessary) in controlling water conning or delaying the breakthrough. Investigating the impact of key reservoir parameters on this phenomenon in one of the Iranian fractured gas field is the aim of this article. For this purpose, a synthetic model was constructed and simulated using real reservoir data in a radial system. Then, the effect of different reservoir parameters on the percentage of water cut production was analyzed. By comparing the results of the simulations, it is concluded that the injection of non-permeable fluid flow in the bottom layers of production formation decreased the percentages of water cut and increased the breakthrough. Also, it was proved that fracture permeability, the thickness of the gas column, gas flow rate, perforation position and aquifer strength are the most important parameters to occur and exacerbate water conning. It was also concluded that the less pressure drop was exerted on the reservoir, and the water production was reduced by increasing the matrix porosity to fracture porosity.

WC-Co composite which is named hardmetal and has widespread application in excavation industry, usage of these composites with nano-structure, is concerned recent years. In this research, WC-9Co-0.7VC composite in two cases, microstructure and nanostructure, was made by rapid hot pressing process, and then their metallographic inspection and mechanical properties were compared with each other. Mechanical properties in micro-hardmetal and nano-hardmetal; such as, density, hardness, fracture toughness and transverse rupture strength were measured. Approximately, in all properties, nano-hardmetal had better results than micro-hardmetal. The microstructure of samples was checked out by using of scanning electron microscope. It seems that nanometer WC grains leads to this upgrade. In measurements, it turned out that, hardness and transverse rupture strength increased %33 and %21, respectively. Due to the application of this composite in oil and gas well drilling, nano-structures can improve function and working life of these tools.