An optimized polymer gel, known as temporary gel, based on polyacrylamide sulfonated copolymer, and a chromium acetate hydroxide were synthesized to close‐in the wells during applying well servicing work. Based on bottle tests, polymer gel with 28 000 ppm of polymer concentration, and 0.105 ratio of crosslinker to polymer, was selected. The pressure effect within the range of 1000 to 4000 psi indicated not impressive effect of pressure on the gel properties. As the results of creep test clarified, yield strength of the gel was measured at temperature of 90? C, and 2000 Pa. Moreover, the results of an experiment under simulated well condition showed a linear correlation between the height of polymer gel column, and the strength and persist

Asphaltene is the heaviest fraction of oil, and if the thermodynamic conditions of oil change, it can be separated from oil precipitate. Of common methods for preventing asphaltene precipitation, using predictive methods, biological methods and injection of dispersants can be mentioned. In this study, the effect of two dispersants of toluene and dodecylbenzene sulfonic acid on asphaltene precipitation of a dead and a live oil sample has been investigated. According to the results, these dispersants in dead oil create an optimum point for asphaltene precipitation. In live oil, these dispersants reduce asphaltene precipitation down to 70%. In addition, it was observed that as an effect of injecting these dispersants, the average sizes of asph

The main objective of this work was to assess the optimization of Fe and Cu bioleaching from converter slag using Acidithiobacillus ferrooxidans. Important parameters that contribute to the bioleaching process include initial pH, initial Fe 2+ concentration and pulp density. In order to optimize these parameters, the response surface methodology (RSM) was applied. The maximum simultaneous Fe and Cu recovery yields were 95% and 100%, respectively. The optimum conditions were initial pH 1.8, initial density 1.4 g/100 mL and initial Fe 2+ 7.3 g/L. The comparison between chemical leaching and bioleaching results showed that bioleaching improved the recovery yields of Fe and Cu by 26% and 33%, respectively. The modified shrinking core model was

Organic deposition especially asphaltenes in reservoirs, wells, and equipment has a detrimental effect on petroleum economy. Generally, for chemically control of asphaltene precipitation using dispersants and inhibitors of precipitation or solvents of asphaltene is very common. Although asphaltene in crude oil is stable under specific conditions, but there is no assurance that the system will be stable and asphaltenes could be remaining in suspension state. In this study, the kinetic effects of three dispersants on stabilization of asphaltene aggregates were investigated by turbidity measurement method. Turbidity measurement showed as the dispersant strength rises, the turbidity of unstable sample containing dispersant less declines versus

Asphaltene precipitation and subsequent deposition in production tubing and topside facilities present significant cost penalties to crude oil production. Therefore, it is highly desirable to predict their phase behavior and the efficiency of dispersants in preventing or delaying deposition. Very few studies have been carried out on the molecular interactions between asphaltenes and different dispersants. As a result, the mechanisms by which dispersants stabilize asphaltenes are still open to discussion. The authors introduced a new method to characterize asphaltenes in perturbed chain statistical association fluid theory equation of state (EOS; perturbed-chain statistical association fluid theory EOS [PC-SAFT-EOS]) and correctly model the

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A key parameter for the application of polymer gels in water shut off treatment is the adsorption of polymer gel onto the rock surface. So, the adsorption properties of a nanocomposite hydrogel were discussed in this research by crosslinking of sulfonated polyacrylamide/sodium montmorillonite aqueous solutions with chromium triacetate. The X-ray diffraction patterns indicated that exfoliated type of microstructure was formed. In addition, fourier transform infrared spectroscopy was used to prove the nanocomposite hydrogel interacted with the rock surface qualitatively and the scanning electron microscopy to determine the surface characteristics of the nanocomposite hydrogel layer adsorbed on powdered rock surface. The general behavior of th

One of the unique properties of hydrogels is the dramatically change in their volume and shape. In this research, conventional hydrogels (composed of sulfonated polyacrylamide and Cr (OAc) 3 as copolymer and crosslinker, respectively) were investigated versus nanocomposite (NC) hydrogels for the purpose of achieving suitable composition with ability of high amount of equilibrium swelling ratio and low amount of salt sensitivity factor (f). The results showed that high ratio of Cr (OAc) 3/copolymer (> 0.39) and high concentration of copolymer (> 27 000 ppm) were suitable areas for conventional hydrogels because of minimum f factor with still low ability of gel swelling. However, the results of NC hydrogels with composition of copolymer conce

Polymer gel treatment is an economic and effective method to reduce excessive water production in hydrocarbon reservoirs. However, there exist unsuccessful applications of polymer gel due to a mismatch of theoretical and experimental results in field conditions. In this study, a gel treatment experiment was implemented using a novel test method which includes a unique two‐dimensional coreflooding setup and a new procedure of simultaneous oil and water injection. To form the gel in situ, a Cr (III)‐acetate‐hydrolyze polyacrylamide (HPAM) gelant was used. The results showed that polymer gel could be successfully applied to water shut‐off (WSO) treatments in low‐permeable porous media with radial flow. The residual resistance factors