Preparation and Evaluation of Acrylate Polymers as Pour Point Depressants for Lube Oil

Abstract

In the present work, twenty polymeric additives were prepared and used as pour point depressants for lube oil, via copolymerization of different ratios of styrene with different esters of acrylic acid. The efficiency of the prepared copolymers as flow improvers (pour point depressants) for a base lube oil were studied. It was found that the efficiency increases by decreasing the concentration of the prepared copolymers, decreasing the chain length of alkyl groups. The efficiency decreases by increasing the styrene content in the prepared copolymers.     

Comparative studies of the rheological behavior and microstructural properties of emulsions (oil/distilled water phase) and (oil/Lias water phase)

Abstract

The rheological behavior of crude oil and their emulsions were investigated as a function of two water types (distilled water and the LIAS water). The focus of this work is to obtain more knowledge about the effect of LIAS water concentration, which used to maintain pressure and produced from production of crude oil in the oil fields Tin Fouye Tabankort-south Algeria, on the rheological properties of crude oil. The rheological parameters were measured by using AR-2000 rheometer at 15?°C under dynamic and shear testing conditions. The measured data were first classified into two groups for Newtonian and non-Newtonian fluids. Depends on the type and concentration of water, the non-Newtonian behavior was described in better way by the Casson, Power law and the Herschel–Bulkley models. The results indicated that the viscosity, the yield stress, the elastic modulus, (G′), the loss modulus, (G″), and the microstructure of the prepared emulsions not only varied with water concentration but also by water types.     

Synthesis and Evaluation of Copolymers as Pour-point Depressants

Abstract

α-Olefin maleic anhydride copolymers were prepared by reacting C₈ or C₁₄ olefin with maleic anhydride, then esterified with dodecyl or NAFOL 1822B alcohol, purified and characterized through average molecular weight, polydispersity index, and infrared spectroscopy. A waxy crude oil (pour point = 21°C and wax content = 18.9 wt%) was treated with the four synthesized additives as pour-point depressants and determined using x-ray diffractometer. It is found that the x-ray diffraction patterns of waxes with additives are remarkably different from those without additives. The NAFOL 1822B ester of 1-tetradecene maleic anhydride copolymer also show stronger interaction with the wax than NAFOL 1822B ester of 1-octene copolymer, dodecyl ester of 1-tetradecene maleic anhydride copolymer, and dodecy ester of 1-octene maleic anhydride copolymer. These effects can be attributed to the chain length of side hydrocarbon. The wax solubilization is a function of copolymer.     

Synthesis and Evaluation of Viscosity Index Improvers and Pour Point Depressant for Lube Oil

Abstract

In the present work, four compounds were prepared by copolymerization of maleic anhydride with tetradecene to give (A), and then the copolymer (A) was esterified by a series of n-alkanol having different alkyl chain length. The compositions of prepared compounds were determined by molecular weight and by IR spectroscopy. The efficiency of the prepared compounds as viscosity index improvers for lube oil was studied. From the data, it was found that the efficiency as viscosity index improvers increases by increasing the concentration of these additives and by increasing the alkyl chain length of the alcohol used. The efficiency of the prepared compounds as pour point depressants for lube oil was studied also and shows that the prepared compounds depress the pour point of the lube oil successfully.     

Poly (3-Hydroxybutyrate) Production from Crude Oil by Haloarcula sp. IRU1: Optimization of Culture Conditions by Taguchi Method

Abstract

Petroleum contamination is a widespread and well-recognized global environmental threat to human health and ecosystems. Haloarcula sp. IRU1 was cultivated axenically in synthetic liquid media with crude oil as sole carbon and energy source. After 5 days' incubation, cell dry weight (CDW) and poly (3-hydroxybutyrate) (PHB) production were studied by conventional methods. The optimized conditions for the maximum production of PHB were temperature 47°C, crude oil 2%, yeast extract 0.4%, and NaH₂PO₄, 0.016% as carbon, nitrogen, and phosphorus sources, respectively. In conclusion, Haloarcula sp. IRU1 can biodegrade crude oil and use it as a carbon source for PHB production.     

LOW TEMPERATURE FLOW CHARACTERISTICS OF SOME WAXY CRUDE OILS IN RELATION TO THEIR COMPOSITION : PART I WITH AND WITHOUT POUR POINT DEPRESSANT ADDITIVES

ABSTRACT

The yield stress, plastic viscosity and apparent viscosity and the dependence of the latter on the shear rate have been studied at different temperatures below pour point of Lingala (Krishna-Godavari basin, Eastern coast), Duliajan (Eastern region of Assam), Rava (Godavari basin) and Bombay-High (off-shore western region) indigenous crude oils

Four different commercial pour point depressant additives have been used to study their effects on the pour point, yield stress and plastic viscosity

From this study it has been found that wax concentration and its composition are primarily responsible for the variation in the pour point, and crude base composition has a small effect. However, the response of the pour point depressant additive in effecting the change in the pour point is primarily governed by the liquid matrix. As the temperature is lowered both the yield stress and plastic viscosity increase in case of each crude oil. However, the magnitude is dependent on the nature of the crude oil. With pour point depressant additives, the yield stress and plastic viscosity are decreased and this decrease is a function of nature of the liquid matrix of the crude oil and concentration of the additive     

LOW TEMPERATURE FLOW CHARACTERISTICS OF SOME WAXY CRUDE OILS IN RELATION TO THEIR COMPOSITION : PART II EFFECT OF WAX COMPOSITION AND CONCENTRATION ON THE DEW AXED CRUDE OILS WITH / WITHOUT ADDITIVES

ABSTRACT

In this part of the work the effect of wax concentrations on the rheologica! properties of the dewaxed Duliajan (Assam) and Lingaia crude oils have been studied. The dewaxing of the crude oil was done by removing n-paraffins from the crude oil by urea adduction. The urea adducted n-paraffins concentrate-the wax- was characterized by its carbon number distribution. The urea non adducted oil portion - the denormalized crude oil (DNO)- was characterized for its pour point. The wax in different concentration was then added in the DNO and the change in the rheological properties like pour point, yield stress and plastic viscosity were studied using a Haake Rota Viscometer. The effect of carbon number distribution, i.e. the composition of the wax, on these rheological properties was also investigated. Four different commercial pour point depressanl additives have been used to study their effects on the pour point, yield stress and plastic viscosity of the reconstituted (wax mixed DNO) crude oils.

From this study it has been found that wax concentration and its composition are primarily responsible for the variation in the pour point of the DNO, and the DNO composition has a small effect. However, as seen in the Part I of this paper, the response of the pour point depressant additive in effecting the change in the pour point is primarily governed by the composition of the DNO. The additives have shown better response in the DNO having more aromatic concentrate, as has been found in the case of Duliajan (Assam) DNO.     

Microscopic Study of Oil Flocculation and Coalescence Processes for Understanding the Role of Surfactants in EOR Performance

Abstract

A preliminary microscopic study of oil/oil droplet interactions in surfactant-added water is carried out to understand the oil/water interface changes with time and its effects on oil/oil droplet coalescence. This study is carried out on two oils (olive and crude oil) with varying concentrations of surfactant water ratios. The radii of curvature of the interface between coalescing oil droplets is used as a measure to reflect the change in surface energy. As oil droplets were placed in surfactant-added water, the radii of curvature were measured at three different states. Early state shows very little effect on oil/oil interfaces; in the later state, the effect is greater and interfacial tension decreases rapidly. At quasi-steady state, the state between the early and later, faster rate stage reduces with surfactant concentration in the case of olive oil. Increasing the surfactant concentration does not show the same effect on crude oil. The radii of curvature increase with time by increasing surfactant concentrations in olive oil; an inverse effect is found in crude oil. A natural surfactant prepared from the outer shell of pericarp of soapnut fruit was also used to study droplet formation and coalescence as well as to investigate the impact in interfacial tension and oil mobility.     

Multifunctional Additives Viscosity Index Improvers,Pour Point Depressants and Dispersants for Lube Oil

Abstract

In the present work, some polymeric additives based on styrene-maleic anhydride copolymer were prepared and evaluated as multifunction lube oil additives (viscosity index improvers, pour point depressants, and detergent-dispersant additives). The styrene-maleic anhydride copolymer reacted with different alcohols (dodecyl alcohol, hexadecyl alcohol, octadecyl alcohol, and docosanol) to prepare four different types of esters and aminated with different types of amines (dodecyl amine, hexadecyl amine, and octadecyl amine) to prepare another three co-polymeric additives. Structure of the prepared compounds was confirmed by I.R. spectroscopy. The molecular weights of the prepared copolymers were determined by using gel permeation chromatograph and the percentage of esterification and amination were determined by ¹HNMR. The efficiencies of the prepared compounds as viscosity index improvers, pour point depressants, and detergents-dispersants were investigated. It was found that the efficiency of the prepared compound as viscosity index improvers increases with increasing the concentration of additives in the solution and with increasing the molecular weight of prepared compounds, while the efficiency of the prepared compounds as pour point depressants increases with decreasing the concentration of the prepared polymers. On the other hand, the prepared compounds showed excellent dispersion power.     

Study the Influence of Some Polymeric Additives as Viscosity Index Improvers,Pour Point Depressants and Dispersants for Lube Oil

Abstract

In the present work, some polymeric additives were prepared as pour point depressants, viscosity index improvers and dispersant additives for lube oil, these additives prepared by copolymerization of maleic anhydride with different esters of acrylic acids and then amination. The molecular weights of the prepared copolymers were determined by gel permeation chromatograph (GPC). The efficiency of the prepared compounds as pour point depressants and viscosity index improvers was investigated. It was found that the efficiency of the prepared compounds as pour point depressants increases with decreasing the concentration of the prepared polymers, increasing the chain length of alkyl groups and increases with decreasing the molecular weight. The efficiency of the prepared compounds as viscosity index improvers increases by increasing the concentration of these additives and by increasing the molecular weight of polymer. It was found that the amination of polymer enhance the efficiency of the prepared additives as pour point, viscosity index, and dispersant for sludge.     

Synthesis and Evaluation of Some Polymeric Compounds as Pour Point Depressants and Viscosity Index Improvers for Lube Oil

Abstract

In the present study, some polymeric additives were prepared and used as pour point depressants and as viscosity index improvers for lube oil via copolymerization of maleic anhydride and vinyl acetate with different esters of acrylic acid. The molecular weights of the prepared copolymers were determined by GPC. The efficiency of the prepared compounds as pour point depressant and viscosity index improvers was investigated. It was found that the efficiency of the prepared compounds as pour point depressant increases with decreasing the concentration of the prepared polymers, increasing the chain length of alkyl groups, and increases with decreasing the molecular weight. The efficiency of the prepared compounds as viscosity index improvers increases by increasing the concentration of these additives and by increasing the molecular weight of the polymer.     

Predicting asphaltene precipitation during titration of diluted crude oil with paraffin using artificial neural network (ANN)

Abstract

Asphaltene precipitation from crude oil in underground reservoirs and on ground facilities is one of the major problems in a large portion of oil production units around the world. Many scaling equations and intelligent predictive models using the artificial neural network (ANN) are proposed in the literature but none of them can be applied when crude oil is diluted with any types of paraffin. In this study, feed forward artificial neural network is used for prediction of the amount of asphaltene precipitated weight percent of diluted crude oil with paraffin based on titration tests data from published literature. Trial and error method is utilized to optimize the artificial neural network topology in order to enhance its strength of generalization. The results showed that there is good agreement between experimental and predicted values. This predictive model can be applied to estimate the amount of asphaltene precipitated weight percent when the crude oil is diluted with paraffin and to avoid experimental measurement that is time-consuming and requires expensive experimental apparatus as well as complicated interpretation procedure.     

Synthesis of phthalimide and succinimide copolymers and their evaluation as flow improvers for an Egyptian waxy crude oil

This paper describes the synthesis, characterization and performance evaluation of three phthalimide and three succinimide copolymers of vinyl acetate, styrene and methyl methacrylate as flow improvers for waxy crude oil. The prepared copolymers were named as; (VA)Ph; (St)Ph; (MMA)Ph; (VA)S; (St)S and (MMA)S. These copolymers were characterized by FTIR and ¹H NMR spectroscopy. The molecular weights and nitrogen content of these copolymers were determined by using the GPC technique and the Kjeldhal method, respectively. The rheological properties of crude oil (with and without additives) were studied. From the obtained results, it was remarked that the styrene phthalimide copolymer (St)Ph exhibited the maximum pour point depression (ΔPP_500 ppm = 30). The results of the rheological flow properties showed that the Bingham yield values (τ_β) for crude oil without additives at 15, 27 and 39 °C were 0.286, 0.131 and 0.075 Pa respectively, whereas the τ_β for the treated crude oil by the styrene phthalimide (St)Ph copolymer were 0.021, 0.0164 and 0.0081 Pa at 500 ppm at the same temperatures.     

Inhibition and Promotion of Hydrolysis of Chloride Salts in Model Crude Oil and Heavy Oil

Abstract

The interactions of chloride salts with naphthenic acid and inhibitors during exposure to steam at 100–350°C were investigated in order to understand the release of hydrochloric acid in crude units. Naphthenic acid promoted the release of chlorine from calcium and sodium chlorides by a factor of up to 30 times, forming metal naphthenates in solution. Mitigation of the hydrolysis reactions was achieved with the use of chemical additives in both a model oil and in a Canadian heavy oil.     

STUDY ON BLENDS OF CRUDE OIL WITH SLUDGE LEFT IN KUWAITI OIL LAKES

ABSTRACT

An attempt has been made to determine the optimum amount of light crude oil (API=37) to be added to sludge left in Kuwaiti oil lakes to make a blend that has acceptable properties for refining purposes. Blends of different proportions were prepared and examined. Tests on selected physical properties such as API gravity, salt content, sulfur content, and viscosity were carried out. Analysis of experimental data indicated that a two weight percent blend of sludge with light crude oil would be the most appropriate proportion that will not jeopardize the specifications required by the refinery.

Experimental values of viscosity were compared with some of the available predictive correlations. The true boiling point (TBP) distillation was conducted to obtain yields of different cuts that could be produced out of the optimum proportion of the blends. Distillation curve for the 2wt% blend of sludge with light crude oil was compared with the distillation curves for each component of the blend.     

Changes Associated with Field-Scale Demonstration in a Steam-Stimulated Crude Oil from the Lagunillas Oilfield (Lake Maracaibo,Venezuela)

Abstract

Cyclic steam injection with alkali is currently very commonly used to improve heavy-crude oil production in Venezuela. This work is an analysis of oil-associated water and crude samples from LL-2670 well in the Lagunillas oilfield at Lake Maracaibo (northwestern Venezuela). The aim of this research is to analyze the organic acids thus generated and evaluate chemistry changes in the saturated and aromatic fractions of crude oil during the first cycle of steam stimulation by cyclic injection with alkali. It was noted that the percentages of sulfur and saturates, aromatics, resins, and asphaltenes (SARA) and the American Petroleum Institute (API) gravity varied little in the analyzed crude. In contrast, there were significant variations in the biomarker distribution, particularly in the mono- and triaromatic steranes, benzothiophenes, phenanthrenes, and alkyl-naphthalenes of the crude.     

Effect of Crude Oil Composition and Blending on Flowing Properties

Abstract

The effect of crude oil n-paraffin molecular weight distribution on wax crystallization risk was studied. Sixteen highly paraffinic crude oils from Eastern Venezuela were characterized, in terms of hydrocarbon family distribution, by High Temperature Simulate Distillation (HTSD), Gel Permeation Chromatography (GPC), and wax content. n-Paraffin chain length was correlated with crude oil cloud point and pour point. It was demonstrated that high molecular weight linear paraffins are responsible for crude oil wax precipitation. A quantitative correlation between molecular weight distribution and crude oil flowing properties was also obtained. It was found that the wider the molecular weight distribution, the lower is the wax crystallization risk. Blends of different paraffinic crude oils were prepared and their flowing properties were evaluated in comparison with the original crudes. Cloud points below the mean value were obtained. In some cases, a synergistic effect was observed (cloud points below the minimum of the two crude oils). Blends of some of these crudes with condensates afforded improvements on crude oil flow and a reduction of wax crystallization tendency (cloud point). This phenomenon can be attributed to a combination of two factors: I. increases in C24-n-paraffins, and II. a wider molecular weight distribution.     

The Effect of Commercial Additives as Pour Point Depressants for Fuel Oils

When the crude oil temperature goes below the pour point value wax crystals will come out of solution and tend to plug lines and filters. Additionally, the wax deposited in tanks decreases the storage capacity. In general, wax deposition can cause problems in production, storage, transportation, and consumption. Pretreatment of the crude oil with flow improver or pour point depressants has received the greatest acceptance due to its simplicity and economy. Four commercial additives were evaluated as pour point depressant for fuel oils. The structures of the commercial additives were confirmed by FTIR spectra. The results indicate that the n-alkanes carbon distributions display an obvious normal distribution in fuel oils. The distributions of high carbon n-alkanes are all broad so that wax crystals not precipitate in fuel oil at low temperatures is good. These commercial additives were tested as pour point depressants for fuel oil. The obtained data revealed that the prepared compounds depress the pour point of the fuel oil successfully. Comparison of structures of wax crystals in untreated and treated fuel oil was also done by photomicrographic analysis.     

Predicting the Bubble-Point Pressure and Formation-Volume-Factor of Worldwide Crude Oil Systems

Abstract

This paper presents models for predicting the bubble-point pressure (P _b ) and oil formation-volume-factor at bubble-point (B _ob) for crude oil samples collected from several regions around the world. The regions include major producing oil fields in North and South America, North Sea, South East Asia, Middle East, and Africa. The model was developed using artificial neural networks with 5200 experimentally obtained PVT data sets. This represents the largest data set ever collected to be used in developing P _b and B _ob models. An additional 234 PVT data sets were used to investigate the effectiveness of the neural network models to predict outputs from inputs that were not used during the training process. The network model is able to predict the bubble-point pressure and the oil formation-volume-factor as a function of the solution gas–oil ratio, the gas relative density, the oil specific gravity, and the reservoir temperature. In order to obtain a generalized accurate model, back propagation with momentum for error minimization was used. The accuracy of the models developed in this study was compared in details with several published correlations. This study shows that if artificial neural networks are successfully trained, they can be excellent reliable predictive tools to estimate crude oil properties better than available correlations. The network models can be easily incorporated into any reservoir simulators and/or production optimization software.