PHYSICAL-CHEMICAL STUDY OF ZnO-MWCNT NANOPARTICLES FOR A WATER FLOODING EXPERIMENT IN ENHANCED OIL RECOVERY (EOR)

Extracting the trapped oil is still one of the main challenges faced by the oil and gas industry to this point of time. Conventional recovery methods like chemical, thermal, alkaline and gas are found not able to meet the expectations and demands of the current era. Therefore the industry has started to look forward at non-conventional methods. Nanotechnologywith the impressive size ofparticles gave the hope to tackle this problem. Therefore, injection ofdielectric nanofluids with different surface nature accompanied with electromagnetic waves has been proposed to enhance recovery efficiency in enhanced oil recovery(EOR) stage. It was found that the viscosity of the dielectric nanofluid changes and increases with exposure to electric field which can provide better sweep efficiency during water flooding experiment. Hydrophilic Zinc oxide (ZnO) and hydrophobic MultiWall Carbon Nanotubes (MWCNT) were used as dielectric material. Successfully, ZnO was synthesized by sol-gel method in the presence of gelatin type B as a gelatinization agent with mean size 20 nm. Then the microstructure properties of both of ZnO and MWCNT were investigated

Adsorption isotherm and molecular modeling of phytoconstituents from Dillenia suffruticosa leaves for corrosion inhibition of mild steel in 1.0 M hydrochloric acid solution

Plant extracts as green corrosion inhibitors have gained significant attention in minimizing metallic corrosion due to the presence of heteroatoms and polar groups found in extract molecules. The present work focused on the novel implementation of Dillenia suffruticosa leaves extract (DSLE) as a green corrosion inhibitor for corrosion protection of mild steel in 1 M hydrochloric (HCl) acid. Gravimetric characterizations and adsorption isotherm modeling (Langmuir, Temkin, El-Awady Sips, and Freundlich) showed that DSLE is an excellent corrosion inhibitor with inhibitive performance that increases with increasing extract concentration. Potentiodynamic polarization (PDP) showed that DSLE behaved as a mixed-type corrosion inhibitor. Given that one limitation of using plant extracts is its solubility in polar electrolytes, Monte Carlo (MC) simulations and density-functional theory (DFT) calculations were carried out to investigate the surface adsorption properties between polar and non-polar compounds found in DSLE. The results obtained showed that polar phytocompounds (saponins) were primary agents for corrosion inhibition. Our findings highlight the potential of using polar phytocompounds from Dillenia suffruticosa as green corrosion inhibitors for mild steel particularly in applications containing polar solvents and electrolytes

Empirical Modeling of the Viscosity of Supercritical Carbon Dioxide Foam Fracturing Fluid under Different Downhole Conditions

High-quality supercritical CO2 (sCO2) foam as a fracturing fluid is considered ideal for fracturing shale gas reservoirs. The apparent viscosity of the fracturing fluid holds an important role and governs the efficiency of the fracturing process. In this study, the viscosity of sCO2 foam and its empirical correlations are presented as a function of temperature, pressure, and shear rate. A series of experiments were performed to investigate the effect of temperature, pressure, and shear rate on the apparent viscosity of sCO2 foam generated by a widely used mixed surfactant system. An advanced high pressure, high temperature (HPHT) foam rheometer was used to measure the apparent viscosity of the foam over a wide range of reservoir temperatures (40–120 °C), pressures (1000–2500 psi), and shear rates (10–500 s−1). A well-known power law model was modified to accommodate the individual and combined effect of temperature, pressure, and shear rate on the apparent viscosity of the foam. Flow indices of the power law were found to be a function of temperature, pressure, and shear rate. Nonlinear regression was also performed on the foam apparent viscosity data to develop these correlations. The newly developed correlations provide an accurate prediction of the foam’s apparent viscosity under different fracturing conditions. These correlations can be helpful for evaluating foam-fracturing efficiency by incorporating them into a fracturing simulator

Experimental study on electromagnetic-assisted ZnO nanofluid flooding for enhanced oil recovery (EOR).

Recently, nano-EOR has emerged as a new frontier for improved and enhanced oil recovery (IOR & EOR). Despite their benefits, the nanoparticles tend to agglomerate at reservoir conditions which cause their detachment from the oil/water interface, and are consequently retained rather than transported through a porous medium. Dielectric nanoparticles including ZnO have been proposed to be a good replacement for EOR due to their high melting point and thermal properties. But more importantly, these particles can be polarized under electromagnetic (EM) irradiation, which provides an innovative smart Nano-EOR process denoted as EM-Assisted Nano-EOR. In this study, parameters involved in the oil recovery mechanism under EM waves, such as reducing mobility ratio, lowering interfacial tensions (IFT) and altering wettability were investigated. Two-phase displacement experiments were performed in sandpacks under the water-wet condition at 95°C, with permeability in the range of 265-300 mD. A crude oil from Tapis oil field was employed; while ZnO nanofluids of two different particle sizes (55.7 and 117.1 nm) were prepared using 0.1 wt. % nanoparticles that dispersed into brine (3 wt. % NaCl) along with SDBS as a dispersant. In each flooding scheme, three injection sequential scenarios have been conducted: (i) brine flooding as a secondary process, (ii) surfactant/nano/EM-assisted nano flooding, and (iii) second brine flooding to flush nanoparticles. Compare with surfactant flooding (2% original oil in place/OOIP) as tertiary recovery, nano flooding almost reaches 8.5-10.2% of OOIP. On the other hand, EM-assisted nano flooding provides an incremental oil recovery of approximately 9-10.4% of OOIP. By evaluating the contact angle and interfacial tension, it was established that the degree of IFT reduction plays a governing role in the oil displacement mechanism via nano-EOR, compare to mobility ratio. These results reveal a promising way to employ water-based ZnO nanofluid for enhanced oil recovery purposes at a relatively high reservoir temperature

Optimal Process Parameters for a Thermal-Sprayed Molybdenum-Reinforced Zirconium Diboride Composite on a Dummy Substrate

Thermal spray is an effective process for the fabrication of a metal matrix composite (MMC), where a zirconium diboride reinforcement is embedded in a molybdenum matrix to enable the combining of favorable properties in a new composite. The combination of two leading materials in the category of ultra-high-temperature ceramics (UHTCs) is due to a very high melting point (Mo: 2623 °C and ZrB2: 3245 °C), high thermal conductivity (Mo: 139 W/m°C and ZrB2: 24 W/m°C), good thermal shock resistance, low coefficient of thermal expansion (Mo: 5.35 µm/m°C and ZrB2: 5.9 × 10−6 K−1), retention of strength at elevated temperatures and stability in extreme environments. Thermal spraying of the Mo/ZrB2 composite possesses a non-linear behavior that is influenced by many coating variables. This characteristic makes finding the optimal factor combination difficult. Therefore, an effective and strategic statistical approach incorporating systematic experimental data is needed to optimize the process. In this study, the L9 orthogonal array in the Taguchi approach was utilized to optimize the spraying distance (SD), number of passes (NP), pressure (P) and coat-face temperature (TCF) using a dummy fiberglass substrate. The performance was evaluated based on the coating density (Cd) of the surfaces. Based on confirmation tests, our Taguchi analysis determined the ideal process parameters, which considerably enhanced the coating process. From the output response of the ANOVA, the most influential parameters for achieving a high coating density (Cd) were determined to be SD = 20 cm, NP = 24, P = 4 bar and TCF = 330 °C ((SD.)1-(NP.)3-P2-(S.T.)3). These observations show that the coating density (Cd) was significantly influenced by the coat-face temperature, followed by the number of passes, spraying distance and pressure with the following contributions 6.29, 17.89, 17.42 and 3.35%, respectively

In-situ hydrogenolysis of glycerol using hydrogen produced via aqueous phase reforming of glycerol over sonochemically synthesized nickel-based nano-catalyst

1,3-Propanediol (1,3-PDO) is a commercially valuable chemical for the production of polytrimethylene terephthalate polymers and polyurethane. In this study, the production of 1,3-PDO was investigated via aqueous phase reforming (APR) and selective hydrogenolysis of glycerol over Ni-Ca/CeO2 catalysts synthesized by sonochemical (Us) and wet impregnation (WI) methods. The experiments were performed in a batch reactor at 20 bar, 230 ℃, and 450 rpm for 1 h. The synthesized catalysts were characterized using XRD, TEM, FESEM, BET, H2-TPR, XPS, CO-chemisorption, and NH3-TPD to better understand the physio-chemical and surface characteristics. The results revealed that sonochemical catalysts showed a larger surface area, smaller crystallite size, low reduction temperature and more homogenous particle distribution than wet impregnation catalysts. For both preparation methods, monometallic Ni/CeO2 catalysts showed the highest activity, whereas Ca modification of Ni/CeO2 catalysts significantly decreased the activity of the catalysts. The highest yield and selectivity of 1,3-PDO were 19.54% and 52.73%, respectively, using Ni/CeO2_Us catalyst. The best catalyst was further utilized for parameters optimization study to observe the effect of varying glycerol concentration (10 to 25 vol.%), temperature (210 to 250 ℃) and pressure (10 to 30 bar) on the yield and selectivity of 1,3-PDO and glycerol conversion. The results demonstrated that the highest yield (19.54%) and selectivity (52.73%) of 1,3-PDO were obtained over 10 vol.%, 230 ℃ and 20 bar with glycerol conversion of 54.26%. This present study provides a promising and economical process of converting glycerol to 1,3-PDO, which has wide applications in the industry

Synthesis, characterisation, and performance evaluation of promoted Ni‐based catalysts for thermocatalytic decomposition of methane

Thermocatalyatic decomposition (TCD) of methane to COX free hydrogen and carbon nanofibre (CNF) was investigated over a series of self‐designed monometallic Ni catalyst and bimetallic Ni−Cu and Ni−Pd catalysts. The catalysts were synthesised from the wet impregnation method and characterised using a series of complementary techniques include TGA, XRD, BET, TPR, FESEM, TEM, and Raman Spectroscopy. Despite a substantial reduction of surface area in the promoted catalysts, the catalytic activity of the promoted catalyst was enhanced due to the nature of the process which is a metal‐catalysed reaction. As a whole, bimetallic Pd−Ni catalyst with a surface area of 2.76 m2 g−1 possesed the highest conversion of 77 % after 6 h reaction. The overall TCD reaction was found to be first‐order with the calculated activation energy, Ea of 38 kJ mol−1. The methane consumption rates at 1023 K and 1073 K were 0.5 mol s−1gcat−1 and 0.58×104 mol s−1gcat−1 respectively. Meanwhile, the methane consumption rates improved considerably from 0.58 mol s−1gcat−1 to 0.67×104 mol s−1gcat−1 under the methane partial pressure of 41 kPa. The XRD profile of the fresh catalysts revealed that mixed oxides were formed over the surface of the support upon the addition of Cu and Pd to 50 %Ni/Al2O3. Moreover, the formation of carbon nanofibers followed both tip and base growth mechanisms as evident from the TEM images. Larger and wider carbon fibres were found in the Pd promoted catalyst

Experimental Investigation of Surfactant Partitioning in Pre-CMC and Post-CMC Regimes for Enhanced Oil Recovery Application

The applications of surfactants in Enhanced Oil Recovery (EOR) have received more attention in the past decade due to their ability to enhance microscopic sweep efficiency by reducing oil-water interfacial tension in order to mobilize trapped oil. Surfactants can partition in both water and oil systems depending on their solubility in both phases. The partitioning coefficient (Kp) is a key parameter when it comes to describing the ratio between the concentration of the surfactant in the oil phase and the water phase at equilibrium. In this paper, surfactant partitioning of the nonionic surfactant Alkylpolyglucoside (APG) was investigated in pre-critical micelle concentration (CMC) and post-cmc regimes at 80 °C to 106 °C. The Kp was then obtained by measuring the surfactant concentration after equilibration with oil in pre-cmc and post-cmc regimes, which was done using surface tension measurements and high-performance liquid chromatography (HPLC), respectively. Surface tension (ST) and interfacial tension (IFT) behaviors were investigated by performing pendant and spinning drop tests, respectively—both tests were conducted at high temperatures. From this study, it was found that APG was able to lower IFT as well as ST between water/oil and air/oil, and its effect was found to be more profound at high temperature. The partitioning test results for APG in pre-cmc and post-cmc regimes were found to be dependent on the surfactant concentration and temperature. The partitioning coefficient is directly proportional to IFT, where at high partitioning intensity, IFT was found to be very low and vice versa at low partitioning intensity. The effect of temperature on the partitioning in pre-cmc and post-cmc regimes had the same impact, where at a high temperature, additional partitioned surfactant molecules arise at the water-oil interface as the association of molecules becomes easier

Oil recovery performance and differential pressure of SDBS surfactant flooding as a function of injected PV.

<p>Oil recovery performance and differential pressure of SDBS surfactant flooding as a function of injected PV.</p

Schematic representation of deformation of oil drop, surrounded with nanoparticles, by an electric field.

<p>Schematic representation of deformation of oil drop, surrounded with nanoparticles, by an electric field.</p