Rheological properties of bitumen emulsion modified with NBR latex

NBR, a copolymer of butadiene and acrylonitrile, is used for applications requiring resistance to petroleum oils and gasoline. So using NBR as a modifier in bitumen, resistance against the destruction of gasoline and diesel oil will be increased. In this work, rheological properties of bitumen emulsion modified with NBR latex have been investigated. Bitumen emulsion samples were provided with various percent of NBR latex, and the residues of normal and modified bitumen emulsion were tested using ordinary and dynamic shear rheometer (DSR) methods. Using NBR latex as a modifier caused an increase in the softening point of bitumen emulsion residue as well as a decrease in the penetration grade and temperature sensitivity. At the end, by analyzing temperature sweep curves of DSR, it was found that modified bitumen emulsion residues with more than 6% NBR in residue have higher rutting potential temperatures.     

Applying FCM-ANFIS algorithm as a novel computational method for prediction of viscosity of bitumen and heavy alkane mixture

Recently the studies expressed that the noticeable number of oil reservoirs in all over the world are heavy oil and bitumen reservoirs. So the importance of enhancement of oil recovery (EOR) processes for heavy oil and bitumen reservoirs is highlighted. The Dilution of the reservoir fluid by solvents such as tetradecane is one of well-known methods for these types of reservoirs which effects oil recovery by decreasing viscosity. In the present study, Fuzzy c-means (FCM) algorithm was coupled with Adaptive neuro-fuzzy inference system (ANFIS) to predict viscosity of bitumen and tetradecane in terms of temperature, pressure and weight percent of tetradecane. The coefficients of determination for training and testing steps were calculated such as 0.9914 and 0.9613. The comparison of results and experimental data expressed that FCM-ANFIS algorithm has great potential for estimation of viscosity of bitumen and tetradecane.     

Analysis of coalescence process of methane hydrate in emulsion system

In oil and gas exploitation and pipeline transportation, hydrate formation poses a significant hidden danger to pipeline safety. Hydrates in the pipelines can coalesce easily on the inner wall surface. Therefore, studying the growth characteristics of hydrates in a multicomponent environment is crucial pipeline anti-blocking technology. Hence, two types of white oil emulsion, S85?+?T20 and S85?+?SDS, were prepared using sorbitol three oleic acid ester, polyoxyethylene sorbitol monoanhydride, and sodium dodecyl sulfate as dispersants. The mechanism of methane hydrate blockage in emulsion and particle systems at 40% moisture content was analyzed. The hydration reaction induction time and phenomenon characteristics of the two were compared, and the effect of the first 30?min particle size change on the hydration reaction was observed by focused beam reflectance measurement. The experimental results indicate that adding particles to the S85?+?SDS emulsion system can shorten the time of hydration reaction dissolved gas significantly, while the hydrophilic particle system will reduce the droplet size at a certain concentration, inhibit the heat transfer and mass transfer between molecules, and prolong the induction of hydrate formation.     

Lube oil from blends of Nigerian Escravos light and Agbabu bitumen by empirical modeling

Abstract

Blends of Escravos light crude and Agbabu bitumen were prepared, distilled and characterized to investigate the effect of the blending on the yield and properties of the distillation fractions. The specific gravity, sulfur content, pour point and flash point of the blends were dependent on the proportions of the components. Regression analysis of the yields of distillation fraction gave robust empirical models. The predicted optimal blend of equal amounts of Escravos and Agbabu bitumen gave distillation fractions similar in properties and yield to the Russian Urals crude. Light components from the Escravos played enhanced solubilization of the heavier components in the bitumen.     

PSO-ANFIS modeling of viscosity for mixtures of Athabasca bitumen and a high-boiling n-alkane

The bitumen and heavy oil reservoirs are more in number than light crude oil reservoirs in the world. To increase the empty space between molecules and decrease viscosity, the bitumen was diluted with a liquid solvent such as tetradecane. Due to the sensitivity of enhanced oil recovery process, the accurate approximation for the viscosity of mentioned mixture is important. The purpose of this study was to develop an effective relation between the viscosity of Athabasca bitumen and heavy n-alkane mixtures based on pressure, temperature, and the weight percentage of n-tetradecane using the adaptive neuro-fuzzy inference system method. For this model, the value of MRE and R² was obtained as 0.34% and 1.00, respectively; so this model can be applied as an accurate approximation for any mixture of heavy oil with a liquid solvent.     

The rheological properties of a bitumen emulsion modified with two types of SBR latex

Bitumen emulsions have recently been taken as one of the most frequently used binders for asphalt surface treatments (AST). Making use of modified bitumen emulsion is necessary to improve AST. Styrene butadiene rubber (SBR) is one of the most commonly used modifiers. The present research study tested the residue of normal and modified bitumen emulsion with different percentages of SBR and X-SBR using ordinary and dynamic shear rheometer methods. The findings revealed that increasing latex SBR led to increasing softening point and needle penetration, so that temperature sensitivity of bitumen residue is reduced. The stiffness of modified bitumen emulsion residue improved significantly by increasing the percentage of SBR. Furthermore, comparing the effect of SBR and X-SBR on bitumen emulsion uncovered that in equal polymer percentage of 6%, X-SBR promoted performance graded for at least one performance grade. Finally, the study is innovative as it dealt with the comparison of high-temperature performance analysis of the impact of polymer percentage simultaneous with that of SBR structure on improving bitumen emulsion.     

CTAB诱导膨润土乳液转相机理及其在可逆乳化油基钻井液中的应用

针对目前油基钻井液对油井完井损害问题,结合Pickering乳液高稳定性的特点,通过改变表面活性剂CTAB的浓度,采用原位活化工艺制备了具有不同表面润湿性的膨润土固体颗粒,研究了CTAB诱导膨润土乳液转相机理。Zeta电位及接触角的变化表征膨润土颗粒亲水、亲油性及表面润湿性的变化;膨润土乳液体系电导率及微观形貌的变化表征乳液转相行为。实验结果表明,通过改变CTAB浓度可实现对膨润土颗粒表面润湿性的改变,进而诱导膨润土乳液发生两次相转变行为。应用性能研究表明,该可逆乳化油基钻井液体系热稳定性良好,滤失量小,解决了传统油基钻井液对油井完井的损害问题。     

Effect of a nonionic surfactant on the formation of natural gas hydrate in a diesel emulsion system

Abstract

In order to investigate the effect of different nonionic surfactants on hydrate formation in oil-water emulsion systems, the hydrate formation experiments were carried out in a diesel water-in-oil emulsion system with a water cut of 40% using nonionic surfactants such as Span80, Tween80, Span20 and Tween20, respectively. The results show that under the experimental conditions of 275?K and 7?MPa, a certain concentration of nonionic surfactant can promote the growth of hydrates in diesel emulsion systems, shorten the hydration reaction time, and have a significant effect on the improvement of gas storage density. The combination of Span80 and Tween80 in a mass ratio of 1:1 was the most effective in promoting the formation of hydrate in the emulsion system. When the mass fraction was 0.5%, the hydration reaction time was the shortest and the hydrate gas storage density was the highest. Due to the addition of the nonionic surfactant, a stable interfacial film and interfacial charge are formed around the water droplets of the emulsion system, making it difficult for the droplets to approach and polymerize, which maintains the stability of the water-in-oil emulsion system and has great reference value for the study of hydrate storage and transportation.     

Influence of storage conditions on the stability of asphalt emulsion

The influence of storage temperature, environment, and containers on the stability and particle size distribution of asphalt emulsion is studied. The results indicate that the stability of asphalt emulsion decreases with the storage time. At the same storage time, the higher the storage temperature, the worse the stability of asphalt emulsion, and the stability of asphalt emulsion stored in the laboratory is better than that stored in the car. The stability of asphalt emulsion stored in an aluminum container is same as that stored in a plastic container, but the stability of asphalt emulsion stored in a iron container is worse. Among the three factors, storage temperature, environment, and container, the maximum influence is of iron container, and the minimum influence is of storage temperature of 40°C.     

稠油乳状液的流变性试验研究

用四种不同的粘性原油乳状液进行了乳状液流变性的研究。结果表明，剪切应力与剪切速率的关系和液滴尺寸大小密切相关，视粘度和非牛顿性随液滴尺寸减小而增大。大部分乳状液在低剪切速率下（＜５０Ｓ－１）剪切变稀，当剪切速率超过５００ｓ－１时呈现牛顿流体性质。因此．液滴尺寸是乳状液流变性研究中的重要因素。     

乳化程度对复合体系提高采收率的影响

针对化学驱过程中驱油剂在岩心内会与原油产生乳状液,并对采收率产生一定影响的现象,通过对一元、二元、三元体系进行界面张力测定、测量体系与模拟油配制的乳状液的粒径、分析乳状液稳定性及贝雷岩心驱油实验,考察了乳化程度对复合体系驱油效果的影响.实验结果表明,三元体系与模拟油形成的乳状液平均粒径最小、稳定性最好、化学驱采收率最高...     

Extractive deasphalting as a method of obtaining asphalt binders and low-viscosity deasphalted hydrocarbon feedstock from natural bitumen

The peculiarities of the composition of natural bitumen from Russian Federation deposits give rise to further processing and transportation problems due to necessity of construction of processing units close to their production areas. In order to solve this problem, a method of pretreatment of natural bitumen was proposed, as a result, potential asphalt binders and low-viscosity deasphalted oil suitable for transportation to refineries are produced. Based on experimental data, the optimal conditions for the process were selected. It was recommended to carry out the first stage of crude preparation, namely thermomechanical dehydration of bitumen, with an end-point for distillation of 150 °C. This solved the problem of stable water-hydrocarbon emulsions and further dewatering of bitumen, and excluded the possibility of destruction reactions resulting in more unstable hydrocarbon compounds. At the next stage, it was proposed to carry out the process of deasphalting of bitumen with acetone at a solvent:crude ratio of 3:1. Therefore, production of deasphalted oil, with viscosity close to that of natural crude oil, and asphalt, as a feedstock for the production of universal road bitumen, intended for both summer and winter operating conditions, was shown.     

Application of fuzzy c-means algorithm as a novel method to predict density of mixtures of Athabasca bitumen and heavy n-alkane

The significant number of oil reservoir are bitumen and heavy oil. One of the approaches to enhance oil recovery of these types of reservoir is dilution of reservoir oil by injection of a solvent such as tetradecane into the reservoirs to modify viscosity and density of reservoir fluids. In this investigation, an effective and robust estimating algorithm based on fuzzy c-means (FCM) algorithm was developed to predict density of mixtures of Athabasca bitumen and heavy n-alkane as function of temperature, pressure and weight percent of the solvent. The model outputs were compared to experimental data from literature in different conditions. The coefficients of determination for training and testing datasets are 0.9989 and 0.9988. The comparisons showed that the proposed model can be an applicable tool for predicting density of mixtures of bitumen and heavy n-alkane.     

An adaptive modeling of petroleum emulsion formation and stability by a heuristic multiobjective artificial neural network-genetic algorithm

In this work, experimental and statistical modeling and optimization of process parameters for maximizing the o/w emulsion stability was carried out using the multiobjective artificial neural network-genetic algorithm (ANN-GA) coupled with response surface methodology. The independent model constrains were oil concentration (10–50% v/v), surfactant concentration (2–10% v/v), stirring intensity (2000–6000 rpm), stirring time (5–20 min), and pH (2–12). The responses were turbidity (τ) and emulsion stability index (ESI₂₄). This fact that there is a reasonably good agreement between the experimental data and the predicted values was shown by the modeling results. The optimized conditions predicted by hybrid ANN-GA model to maximize ESI₂₄ ( = 94.71) with 4.8% error were: oil concentration 50% v/v, surfactant concentration 5.571% v/v, stirring speed 6000 rpm, stirring time 5.97 min, and pH 12. The accuracy of the model is confirmed by the comparison between the predicted and experimental data. The proposed hybrid ANN-GA model was found to be useful for the modeling and optimization of process parameters for emulsion stability analysis and the other emulsification process.     

应用边界元模拟方法分析复杂海底地震散射特征

边界元法对随机起伏的复杂海底界面具有良好的适应性.比较了边界元法与有限差分法对复杂断层模型的模拟精度,并验证了边界元法的有效性.利用边界元法对复杂海底模型进行波场模拟,反映起伏海底界面对地震波传播的影响;利用统计参数描述复杂海底地貌特征,将崎岖海底界面划分为快、慢变化和强、弱起伏等4种特征类型.根据不同统计参数的选择建立崎岖海底理论模型,利用边界元法对不同类型的崎岖海底理论模型进行模拟研究,同时与实际海底资料相对比,分析了复杂海底地震散射特征.此项研究成果可为复杂海底地区目标导向地震观测系统设计和采集参数优化提供理论依据.     

Extraction of aromatic from lube oil using a surfactant as an additive

Solvent extraction is a practical method for the reduction of lube oil aromatic content. Common solvents are phenol, furfural, and N-methyl pyrrolidone (NMP). The extractive power and the selectivity parameters can be increased by the addition of surfactants, which facilitates phase separation and consequently increases the refinery yield. The operatory extraction temperatures and surfactant concentrations ranged, respectively, from 333.15 to 343.15 K and from 0.01 to 0.1%wt. Optimal extraction conditions were systematically determined by measuring the temperatures and surfactant concentrations. The amounts of aromatic, paraffinic, and naphthenic compounds were compared to ASTM standards, namely refractive index (RI), viscosity, molecular weight, and sulfur content. The experimental results show that the best results were realized with 0.01%wt of surfactant and at 343.15 K.     

Experimental study on the viscosity reduction of heavy oil by using of a new type of micro-emulsion

In order to achieve an efficient exploitation of heavy oil reservoirs, a new type of micro-emulsion is prepared with alkyl phenoxy carboxylic acid, co-surfactant (alcohols), diesel oil and water to efficiently reduce the viscosity of heavy oil. With the increase of the chain length of the co-surfactant in a certain range, a larger area of the micro-emulsion region can be obtained. Besides, a clear and transparent micro-emulsion can be obtained when the volume ratio of water-diesel oil is from 8:2 to 5:5. Under the action of micro-emulsion, the viscosity reduction rate of heavy oil reaches over 90% and the electrical conductivity can be greatly increased when the addition of the mass concentration of micro-emulsion is 1%. The results can provide a technical basis for the efficient exploitation of heavy oil reservoirs.     

Estimation of water content of natural gases using particle swarm optimization method

A precise estimation of natural gas water content is a significant constraint in appropriate planning of natural gas production, processing services and transmission. The main contribution of this research is to develop a machine learning approach for predicting water content of sweet and sour natural gases. In this regard, a joining of particle swarm optimization and an artificial neural network was utilized. The suggested model presents good predictions of the sour natural gas water content with following circumstances, including CO₂ contents of 0–40 mol%, H₂S contents of 0–50 mol%, pressures in range from atmospheric to 70,000 KPa for sour gas and 100,000 KPa for sweet gas, and temperatures from 10–200°C for sweet gases and 10–150°C for sour gases.