Journal of Petroleum Science and Technology
Volume:10 Issue: 3, Summer 2020

Entropy analysis, along with convective heat transfer within rotating cylinders of the annulus, is presented using a purely analytical approach for Giesekus rheological model. Two different types of boundary conditions are considered: (a) the constant and different temperature at walls, (b) constant heat flux at the outer wall, and constant temperature at the inner wall. Also, the derived velocity and temperature profiles are coupled in the entropy equation for obtaining the volumetric entropy-generation and the Bejan number expressions. Moreover, the effects of Deborah number (De), mobility factor (α), group parameter (Br/Ω), Brinkman number (Br), and velocity ratio (β) on the above parameters are investigated. Ultimately, results indicate that increment of Brinkman number and group parameters increases irreversibility except when both cylinders rotate with identical angular velocity in the same direction.

Energy storage is one of the major challenges during the last decades. Natural gas adsorption on porous materials has notable advantages in comparison with the other approaches. Due to the lack of adsorption information about Cu-BDC (copper terephthalate), it was synthesized by two different solvent separation procedures and identified using X-ray diffraction (XRD), Brunauer-Emmet-Telller (BET) and thermogravimetric analysis (TGA) techniques. Moreover, equilibrium adsorption measurements were performed for CH4 and CO2 gases in the pressure range 0-50 bar at two various temperatures (293 and 323 K), and experimental adsorption data were modeled with adsorption isotherms. Also, the sample synthesized by the new solvent separation procedure had 918 m2/gr surface area and 0.42 cm3/gr pore volume which were respectively 45% and 50% higher than the traditional method. In addition, this sample has shown CO2 and CH4 adsorption capacity (16.72 and 13.23 mmol gr-1) were desirable in comparison with other conventional Metal-Organic Frameworks (MOFs) and its methane adsorption value was close to DOE (Department of Energy) targets. To investigate the application of the synthesized materials, the selectivity of CO2/CH4 was determined by IAST (ideal adsorbed solution theory) according to the sorption test information of the single components. Finally, adsorption enthalpy of the adsorbates on the two samples was computed using the Clausius-Clapeyron equation and the results were in accordance with the isotherms at two various temperatures (293 and 323 K).

Tuned water (brine with designed compositions) has proved to influence the oil recovery factor. One of the hypotheses supported to understand this technique involves decreasing the oil-water interfacial tension (IFT) and the rock’s wettability alteration, indicated by contact angle (CA) measurements. The literature lacks experimental data regarding the interfacial tension in oil-brine and contact angle in oil-brine-carbonate systems at reservoir conditions considering pressure and temperature, and reservoir rocks. The objective of this study is to obtain new data, at 5,000 psi and 63 °C, on brines with different concentrations. The experiments were carried out in three steps. First, the concentration of sodium chloride was varied 0, 0.25, 0.5, 0.75, and 1 times which is the quantity in a seawater sample. After identifying the best concentration of NaCl (75% of NaCl in original seawater), steps were taken to modify the amount of magnesium 0, 0.5, 1, 2, and 4 times, in the brine. Finally, the same proportions of sulfate were tested. The behavior of IFT and CA towards the function of these various concentrations was also investigated and discussed. Furthermore, the results reveal that the behavior of IFT was not predictable, as the salinity increases at times and decreases at others. This property probably depends more on the compounds in the brine than on the total salinity. Also, the images used to gauge the CA show a greater tendency toward water-wet conditions when the sulfate concentration decreases,and when the magnesium concentration decreases, the images present the opposite effect .

One dimensional basin modelling was used to evaluate the maturity of source rocks, the history of oil generation, and expulsion in north Pazanan syncline and Pazanan, Agha-Jari, and Bangestan anticlines in south Dezful Embayment in the Zagros Basin. The oil generation history of source rocks was obtained by using the basin modelling method. Burial history analysis shows an increase in the rate of burial after the Zagros folding, which it was contemporaneous with huge sedimentation. The high rate of burial is more noticeable in the Pazanan syncline, which it plays an important role in the generation of oil from source rocks. The Sargelu, Garau and Kazhdumi source rocks in the Pazanan syncline have reached the gas-maturity stage. Trapped gas in the Pazanan field could be sourced from the syncline.

Organic geochemical investigations using thin layer chromatography-flame ionization detection (TLC-FID), Gas Chromatography (GC), Gas Chromatography-Mass Spectrometry (GC-MS), API gravimetry, elemental analysis, and isotope-ratio mass spectrometry (IR-MS) were carried out on eleven oil samples from the Sarvak reservoir in the Abadan Plain (SW Iran). Oil chemical composition, source, thermal maturity, age, lithology, and depositional environment of these oils’ source rock were determined in this study. Moreover, Sarvak oils are mainly naphthenic and paraffinic type. Their API degree between 16.2 and 20.14 and about 4.6% sulfur content indicate heavy and sulfur-rich oils. The results of the study of biomarkers, stable carbon isotope composition, trace elements, aromatic and sulfur content indicated that all oil samples are related to a marine-carbonate source rock with strongly anoxic conditions. The absence of oleanane in all oil samples, the variation of Pr/Ph versus δ13C of the whole oil, and C28/C29 steranes versus geological age proved that these oils had been produced earlier than the Late Cretaceous. Furthermore, the distribution of n-paraffins, calculation of Rc (%) from aromatic compounds, CPI (Carbon Preference Index) from gas chromatograms, and biomarker maturity indices indicated that the Sarvak oils are mature. Although the Sarvak oils are heavy, they show approximately maturity of peak oil-generative window, which represents a challenge in this study. It is guessed that the high sulfur content and low API gravity in the Sarvak reservoir oils are due to the presence of sulfur-rich organic matter (type IIS kerogen) in the source rock.

Artificial neural networks (ANN) have emerged as a useful artificial intelligence concept in various engineering applications. Also, ANN only recently has been used in modeling the mechanical behavior of polymers. This study aims to show the applicability of ANNs, to predict and determine the mechanical properties of High Impact Polystyrene (HIPS). Moreover, Izod, Vicat, and MFI of pure HIPS were considered, and the effect of 25 different parameters on them investigated. By using ANN, a black-box model is considered as a calculator of mechanical properties. It is not easy to predict the accurate value of these properties without experimental works for two reasons: (1) the nonlinear behavior of the polymerization process and (2) the inaccuracy of experimental results of measurement of each of the properties. To overcome these problems, an alternative prediction model was proposed for calculating properties using a hybrid ANN-PSO model. All parameters in various cases have been gathered from the industrial DCS system and laboratory for the training of the ANN. First, by using the ANN model, the sensitivity analysis of parameters has been performed. It is then filtered using the effective ANN-PSO hybrid parameters. Out of 25 proposed parameters, 14, 10, 11 of them were selected in MFI, Izod, Vicat, respectively, and used to predict new parameters in the modified ANN. Ultimately, according to the obtained results, it was found that the hybrid ANN-PSO model was powerful in predicting properties with an average relative error of 6, 5, and 1% for predicting considered properties between industrial and computed ANN-PSO hybrid model data.

A novel polymeric nanocomposite pour point depressant (PPD), based on polymethyl methacrylate (PMMA) and montmorillonite (MMT) clay, was synthesized and characterized. For a comprehensive comparison, the influence of neat polymethyl methacrylate (PMMA) and PMMA/clay nanocomposite on reducing pour point, gelation point, apparent viscosity, and yield stress of a model waxy crude oil was investigated, followed by evaluation of their performances precisely. The rheometry test results showed that the addition of 400 ppm of PPMA and 800 ppm of PMMA/clay nanocomposite to waxy crude oil reduced the pour point from 13˚C (for untreated sample) to 0 and -3 ˚C, respectively. Thus, the addition of PMMA/clay nanocomposite to waxy crude oil resulted in a 120% reduction in the pour point.