Mechanistic understanding of asphaltene precipitation and oil recovery enhancement using SiO2 and CaCO3 nano-inhibitors.

Asphaltene precipitation in oil reservoirs, well equipment, and pipelines reduces production, causing pore blockage, wettability changes, and decreased efficiency. Asphaltenes, with their unique chemical structure, self-assemble via acid-base interactions and hydrogen bonding. Nano-inhibitors prevent asphaltene aggregation at the nanoscale under reservoir conditions. This study investigates the effect of two surface-modified nanoparticles, silica, and calcium carbonate, as asphaltene inhibitors and oil production agents. The impacts of these nano-inhibitors on asphaltene content, onset point, wettability, surface tension, and oil recovery factor were determined to understand their mechanism on asphaltene precipitation and oil production. Results demonstrate that these nano-inhibitors can significantly postpone the onset point of asphaltene precipitation, with varying performance. Calcium carbonate nano-inhibitor exhibits better efficiency at low concentrations, suspending asphaltene molecules in crude oil. In contrast, silica nano-inhibitor performs better at high concentrations. Wettability alteration and IFT reduction tests reveal that each nano-inhibitor performs optimally at specific concentrations. Silica nano-inhibitors exhibit better colloidal stability and improve oil recovery more than calcium carbonate nano-inhibitors, with maximum oil recovery factors of 33% at 0.1 wt.% for silica and 25% at 0.01 wt.% for calcium carbonate nano-inhibitors.

Increasing productivity by using smart gas for optimal management of the gas lift process in a cluster of wells.

In the face of the escalating global energy demand, the challenge lies in enhancing the extraction of oil from low-pressure underground reservoirs. The conventional artificial gas lift method is constrained by the limited availability of high-pressure gas for injection, which is essential for reducing hydrostatic bottom hole pressure and facilitating fluid transfer to the surface. This study proposes a novel 'smart gas' concept, which involves injecting a gas mixture with an optimized fraction of CO2 and N2 into each well. The research introduces a dual optimization strategy that not only determines the optimal gas composition but also allocates the limited available gas among wells to achieve multiple objectives. An extensive optimization process was conducted to identify the optimal gas injection rate for each well, considering the limited gas supply. The study examined the impact of reducing available gas from 20 to 10 MMSCFD and the implications of water production restrictions on oil recovery. The introduction of smart gas resulted in a 3.1% increase in overall oil production compared to using natural gas. The optimization of smart gas allocation proved effective in mitigating the decline in oil production, with a 25% reduction in gas supply leading to only a 10% decrease in oil output, and a 33% reduction resulting in a 26.8% decrease. The study demonstrates that the smart gas approach can significantly enhance oil production efficiency in low-pressure reservoirs, even with a substantial reduction in gas supply. It also shows that imposing water production limits has a minimal impact on oil production, highlighting the potential of smart gas in achieving environmentally sustainable oil extraction. Furthermore, the implementation of the smart gas approach aligns with global environmental goals by potentially reducing greenhouse gas emissions, thereby contributing to the broader objective of environmental sustainability in the energy sector.

Assessment of heavy oil recovery mechanisms using in-situ synthesized CeO2 nanoparticles.

This project investigated the impact of low-temperature, in-situ synthesis of cerium oxide (CeO2) nanoparticles on various aspects of oil recovery mechanisms, including changes in oil viscosity, alterations in reservoir rock wettability, and the resulting oil recovery factor. The nanoparticles were synthesized using a microemulsion procedure and subjected to various characterization analyses. Subsequently, these synthesized nanoparticles were prepared and injected into a glass micromodel, both in-situ and ex-situ, to evaluate their effectiveness. The study also examined the movement of the injected fluid within the porous media. The results revealed that the synthesized CeO2 nanoparticles exhibited a remarkable capability at low temperatures to reduce crude oil viscosity by 28% and to lighten the oil. Furthermore, the addition of CeO2 nanoparticles to the base fluid (water) led to a shift in the wettability of the porous medium, resulting in a significant reduction in the oil drop angle from 140° to 20°. Even a minimal presence of CeO2 nanoparticles (0.1 wt%) in water increased the oil production factor from 29 to 42%. This enhancement became even more pronounced at a concentration of 0.5 wt%, where the oil production factor reached 56%. Finally, it was found that the in-situ injection, involving the direct synthesis of CeO2 nanoparticles within the reservoir using precursor salts solution and reservoir energy, led to an 11% enhancement in oil production efficiency compared to the ex-situ injection scenario, where the nanofluid is prepared outside the reservoir and then injected into it.

Performance evaluation of a novel multi-metal catalyst solution obtained from electronic waste bioleaching on upgrading and enhancing oil recovery.

Due to the high costs and associated high CO2 emissions of thermal methods, this study focuses on upgrading heavy oil and enhancing oil recovery within reservoir temperature ranges. In this research, a novel, low-cost, and environmentally friendly multi-metal catalyst has been used, which is actually extracted from electronic waste (E-waste). At optimal conditions, which include 80 °C, 12 h of retention time, and 0.2 % v/v of the multi-metal catalyst, this catalyst effectively reduced the viscosity of heavy oil from 687 to 580 mPa.s. To analyze heavy oil before and after the process, Fourier transform infrared spectroscopy (FTIR) was conducted. FTIR spectra indicates that the multi-metal catalyst has reduced the amount of aromatic compounds, shortened hydrocarbon chains, and decreased double and triple bonds. Micromodel tests were conducted by multi-metal catalyst flooding at optimal temperature and retention time obtained from static experiments. Heavy oil recovery through multi-metal catalyst flooding reached 38 %, which is a 10.5 % increase compared to deionized water flooding. The contact angle of the rock was measured after contact with the multi-metal catalyst. The multi-metal catalyst reduced the contact angle by 55 °, changing the wettability of carbonate rock from oil-wet to water-wet. The absorption test indicates that the multi-metal catalyst dissolves certain metals in the rock, most likely due to the high pH of the catalyst. As a result, the permeability of the rock may increase due to the dissolution of the rock metals.

Assessment of the synthesis method of Fe3O4 nanocatalysts and its effectiveness in viscosity reduction and heavy oil upgrading.

In this research, Fe3O4 nanocatalysts were synthesized systematically microwave-assisted. The effectiveness of the synthesized nanocatalysts in reducing viscosity and upgrading heavy oil was evaluated. The nanocatalysts were investigated for their magnetic and electromagnetic properties. The impact of microwave radiation's time and power on the size and purity of nanocatalysts was investigated. The purities in the crystal network of Fe3O4 nanocatalysts expanded as a result of reducing microwave radiation time and power due to less heat production. Increased temperature leads to dope NH4Cl into the Fe3O4 nanocatalysts crystal network. At: 1 min and power of 400 watts the most satisfactory results in the size and purity of nanocatalysts. The electromagnetic properties, size, and effectiveness of the synthesized Fe3O4 nanocatalysts have been examined to determine the effect of the synthesis method. The performance of Fe3O4 nanocatalysts synthesized by co-precipitation and microwave-assisted viscosity reduction and heavy oil upgrading was evaluated and compared. The crystallite size of the Fe3O4 nanocatalysts synthesized by microwave-assisted was smaller than that synthesized using co-precipitation. Fe3O4 nanocatalysts synthesized by microwave-assisted and the co-precipitation method decreased viscosity by 28% and 23%, respectively. Moreover, Fe3O4 nanocatalysts synthesized by microwave-assisted reduced the sulfoxide index and aromatic index considerably more than the co-precipitation synthesized Fe3O4 (90% against. 48% and 13% vs. 7%, respectively).

Production and characterization of a polysaccharide/polyamide blend from Pseudomonas atacamensis M7D1 strain for enhanced oil recovery application.

Bio-based polymers have better salt and temperature tolerance than most synthetic polymers. The biopolymer solutions have high viscosity, which can lead to reducing the fingering effect and soaring the oil recovery rate. This work aims to produce and characterize a biopolymer from Pseudomonas Atacamensis M7D1 strain, modify the biopolymer yield using Printed Circuit Boards (PCBs) powder as an outer tension in the growth medium, and finally, evaluate the produced biopolymer function for Enhanced Oil Recovery (EOR) purposes. Using PCBs powder to trigger bacteria for higher production yield increases the biopolymer production rate eleven times higher than pure growth medium without additives. Different analyses were performed on the biopolymer to characterize its properties; Gel Permeation Chromatography (GPC) indicated that the produced biopolymer has an average molecular weight of 3.6 × 105 g/mol. This macromolecule has high thermal resistivity and can tolerate high temperatures. Thermal analysis (TGA/DSC) shows only 69.27 % mass lost from 25 °C to 500 °C. The viscosity of 0.5 wt% biopolymer solution equals 3cp, 3 times higher than water. The glass micromodel flooding result shows that biopolymer solution with 0.5 wt% concentration has a 42 % recovery rate which is 24 % higher than water flooding.

Optimization of reaction temperature and Ni-W-Mo catalyst soaking time in oil upgrading: application to kinetic modeling of in-situ upgrading.

Decreasing the conventional sources of oil reservoirs attracts researchers' attention to the tertiary recovery of oil reservoirs, such as in-situ catalytic upgrading. In this contribution, the response surface methodology (RSM) approach and multi-objective optimization were utilized to investigate the effect of reaction temperature and catalysts soaking time on the concentration distribution of upgraded oil samples. To this end, 22 sets of experimental oil upgrading over Ni-W-Mo catalyst were utilized for the statistical modeling. Then, optimization based on the minimum reaction temperature, catalysts soaking time, gas, and residue wt.% was performed. Also, correlations for the prediction of concentration of different fractions (residue, vacuum gas oil (VGO), distillate, naphtha, and gases) as a function of independent factors were developed. Statistical results revealed that RSM model is in good agreement with experimental data and high coefficients of determination (R2 = 0.96, 0.945, 0.97, 0.996, 0.89) are the witness for this claim. Finally, based on multi-objective optimization, 378.81 °C and 17.31 h were obtained as the optimum upgrading condition. In this condition, the composition of residue, VGO, distillate, naphtha, and gases are 6.798%, 39.23%, 32.93%, 16.865%, and 2.896%, respectively, and the optimum condition is worthwhile for the pilot and industrial application of catalyst injection during in-situ oil upgrading.

A Systems-Based Approach for Cyanide Overproduction by Bacillus megaterium for Gold Bioleaching Enhancement.

With the constant accumulation of electronic waste, extracting precious metals contained therein is becoming a major challenge for sustainable development. Bacillus megaterium is currently one of the microbes used for the production of cyanide, which is the main leaching agent for gold recovery. The present study aimed to propose a strategy for metabolic engineering of B. megaterium to overproduce cyanide, and thus ameliorate the bioleaching process. For this, we employed constraint-based modeling, running in silico simulations on iJA1121, the genome-scale metabolic model of B. megaterium DSM319. Flux balance analysis (FBA) was initially used to identify amino acids to be added to the culture medium. Considering cyanide as the desired product, we used growth-coupled methods, constrained minimal cut sets (cMCSs) and OptKnock to identify gene inactivation targets. To identify gene overexpression targets, flux scanning based on enforced objective flux (FSEOF) was performed. Further analysis was carried out on the identified targets to determine compounds with beneficial regulatory effects. We have proposed a chemical-defined medium for accelerating cyanide production on the basis of microplate assays to evaluate the components with the greatest improving effects. Accordingly, the cultivation of B. megaterium DSM319 in a chemically-defined medium with 5.56 mM glucose as the carbon source, and supplemented with 413 µM cysteine, led to the production of considerably increased amounts of cyanide. Bioleaching experiments were successfully performed in this medium to recover gold and copper from telecommunication printed circuit boards. The results of inductively coupled plasma (ICP) analysis confirmed that gold recovery peaked out at around 55% after 4 days, whereas copper recovery continued to increase for several more days, peaking out at around 85%. To further validate the bioleaching results, FESEM, XRD, FTIR, and EDAX mapping analyses were performed. We concluded that the proposed strategy represents a viable route for improving the performance of the bioleaching processes.

Material properties and cell compatibility of poly(γ-glutamic acid)-keratin hydrogels.

Given the great demand for biopolymer and protein-based products from renewable resources, synthesis of a keratin-based hydrogel is presented herein. In this work, a novel hydrogel of poly(γ-glutamic acid) (γ-PGA) and keratin was synthesized through facile EDC·HCl/HOBt chemistry. Since keratin main chain is rich in amino side groups, carboxyl groups in γ-PGA were crosslinked with multi terminated amine groups in keratin. In the following, the hydrogel characteristics, including swelling ratio (2010% at molar ratio of HOBt/EDC = 0.105), in vitro degradation and mass loss (about 20% at day 21 for the aforementioned sample), chemical decomposition and the rheological properties were investigated. The chemical activator agents, enhanced the elastic modulus of swollen hydrogel from around 1000 to 4000 Pa by increasing the crosslinking degree. Despite good biocompatibility for cell growth, some kind of self-assembled keratin hydrogels are not suitable for microscopic observation while the γ-PGA-Keratin hydrogel in our study is transparent. The γ-PGA-Keratin hydrogels possess significant features of rapid hydrogel formation in seconds, maximum swelling ratio of about 2500% maximum elastic modulus (stiffness) of about 4.5 kPa (for the swollen sample) with controllable matrix pore size. For further application, the biocompatibility of the γ-PGA-Keratin hydrogel was assessed by live/dead assay. Recent studies have demonstrated the effect of hydrogel porosity, water absorbing and stiffness on cell spreading, proliferation and differentiation of mesenchymal stem cells. Bone marrow mesenchymal stem cells could be differentiated into various cell fates depending on the elastic modulus of materials they are cultured on. We carried out a statistical study (to skip the cell work labor) to predetermine the proper working span in which we can gain a hydrogel to cover all features needed to be applied for some application like cartilage repair.

Production and physicochemical characterization of bacterial poly gamma- (glutamic acid) to investigate its performance on enhanced oil recovery.

Bacillus licheniformis LMG 7559, which is capable of producing extracellular poly gamma- (glutamic acid) (PGA), was provided for the biopolymer synthesis. Using a modified PGA medium for PGA production, the isolated biopolymer, undergone dialysis process mainly for desalination and removal of other impurities. The bacteria produced high molecular weight biopolymers with a weight average molecular weight (M̅n) of 1.6 × 105 g/mole identified by gel permeation chromatography (GPC). Furthermore, GPC analysis was utilized to determine the poly-dispersity of PGA as well as molecular weight variation by cultivation time. The heavy weight fraction of 1.85 × 105 g/mole with poly-dispersity index of 7.42 was distinguished. For the extracted and dialyzed biopolymer, thermal properties were studied using DSC/TGA by which a mass loss of 36 percent was observed. Eventually, the biopolymer solution was injected into the oil saturated heterogeneous porous medium to evaluate the recovery factor enhancement by PGA flooding. It was found that 31.45% of oil in place was recovered by biopolymer flooding, whereas only 16.6% of oil in place was obtained by water flooding.

Investigation of synergistic effects between silica nanoparticles, biosurfactant and salinity in simultaneous flooding for enhanced oil recovery.

The purpose of this study was to investigate the effect of process parameters including silica nanoparticle (NP) concentration, biosurfactant (BS) concentration, and salinity as well as their synergistic effects on oil recovery in simultaneous flooding. Additionally, the effect of NP morphology (in the BS-NP solution) on oil recovery was investigated in this research. Micromodel flooding tests were designed with a central composite design (CCD) and carried out using BS and spherical silica NPs. The results showed that there is a positive synergistic effect between BS and silica NPs to shift the wettability to the water-wet condition and decrease interfacial tension (IFT), resulting in improved oil recovery. Indeed, the maximum oil recovery was obtained at an optimum salt concentration. Several micromodel tests were then carried out with BS and different-shaped NPs at the optimum point predicted by a mathematical model to study the effect of NP morphology on oil recovery. The results showed that minimum IFT of 1.85 mN m-1 and the most reduction in the glass contact angle of 92.8% could be achieved by the BS-spherical NP solution as compared to those of the BS-non spherical NP solutions, which led to the highest oil recovery of 53.4%. The better performance of spherical NPs was attributed to the higher uniformity, which resulted in better distribution and more effective interactions with crude oil components. The results of core flooding tests showed that the BS-spherical NP solution yielded 26.1% final oil recovery after brine flooding. In addition, the BS-NP solution was more effective in wettability alteration of an oil-wet carbonate rock compared with the BS solution. It was deduced that the main mechanisms involved in oil recovery improvement were wettability alteration to the water-wet state, IFT reduction, and mobility ratio improvement.