STABILIZATION AND CHARACTERIZATION OF HEAVY CRUDE OILIN- (original) (raw)
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There has been much interest in alternative to transport viscous crude oil from reservoir which is much more abundant than conventional oil. There are many authors hard to find the stable of oil-in-water (o/w) emulsion condition which has been considered as critical analysis. In order to reduce the viscosity, the heavy oil is required to modify for reducing their viscosity. Applying diluent and forming o/w emulsion are the selected as alternative for reducing viscosity. The purpose for this investigation is to study factors that influencing stability and viscosity of o/w emulsion. From the observation, o/w emulsions reduced almost six (6) times less than original heavy oil. However, the addition of 40% of light oil reduced oil viscosity from 478.10 mPa.sto 113.40 mPa.s. Thus, the knowledge and understanding factors that influencing the stability and viscosity of o/w emulsion is important due to avoiding of occurring phase inversion phenomena.
Study of the stability and homogeneity of water in oil emulsions of heavy oil
Fuel, 2018
Water-in-oil (W/O) emulsions are present in applications from well drilling to refining and cause diverse problems. The present paper details the results of a study of the stability and homogeneity of W/O emulsions of a heavy oil using the optical microscopy technique. The W/O emulsions used previously dehydrated heavy oil with the addition of increasing volumes of 10, 20, 30, 35 and 40% w/v of deionized water and formation water, under mechanical stirring at 2500, 5000, 10,000 and 15,000 rpm. Moreover, a saturated sodium chloride solution was added to the oil in the contents at 10, 20 and 30% w/v under stirring at 5000 rpm, in order to verify the influence of the electrolyte type on the stability of the emulsions. The W/O emulsions were subjected to a gravitational separation test to verify stability and photomicrographs of the emulsions were analyzed to evaluate the homogeneity and the droplet size distribution (DSD). The results showed that the prepared emulsions were stable and homogeneous even after aging for 30 days and after being subjected to heating. This stability may be related to the high content of resins and asphaltenes in the studied oil. The emulsions prepared with formation water showed higher DSD values than those prepared with saturated NaCl solution and deionized water. This distinction of droplet sizes can be related to the presence of ions of different charges in the formation water.
Experimental Study Of Light Crude Oil-Water Emulsions
2012
This paper made an attempt to investigate the problem associated with enhancement of emulsions of light crude oil-water recovery in an oil field of Algerian Sahara. Measurements were taken through experiments using RheoStress (RS600). Factors such as shear rate, temperature and light oil concentration on the viscosity behavior were considered. Experimental measurements were performed in terms of shear stress–shear rate, yield stress and flow index on mixture of light crude oil–water. The rheological behavior of emulsion showed Non-Newtonian shear thinning behavior (Herschel-Bulkley). The experiments done in the laboratory showed the stability of some water in light crude oil emulsions form during consolidate oil recovery process. To break the emulsion using additives may involve higher cost and could be very expensive. Therefore, further research should be directed to find solution of these problems that have been encountered.
All Days, 2015
An onshore oil well in Japan, referred to as Well M-1 in this paper, experienced a serious emulsion problem soon after the introduction of artificial lift using a hydraulic jet pump. Even though the problem was resolved after switching to a new demulsifier, it is possible that the operator could experience another emulsion problem as the production condition changes in the future and accordingly, the new demulsifier becomes less effective. Therefore, a laboratory case study was conducted to understand not only the cause of the emulsion problem encountered, but also the relative magnitude of several factors affecting emulsion stability. Knowing the conditions that lead to the emulsion problem helps in understanding how to remove the emulsion and in designing intervention treatments to restore long-term well productivity. At first, the oil and brine samples from Well M-1 were mixed and agitated to form emulsion, and subsequently emulsion stability was evaluated. Subsequently, the mixing conditions were altered to investigate the individual impact on the emulsion stability: (1a) replace Well M-1 oil with another field's oil, (1b) replace Well M-1 brine with another field's brine, (2) change concentrations of asphaltene, (3) change concentrations of wax, (4) change concentrations of toluene insolubles, (5) vary temperature between 20 and 70 C, (6) vary shear stress (rotational speed between 3,500 and 15,000 rev/min), and (7) vary water cut between zero and 100%. The result of the emulsion stability in every test was different. All the above factors showed some impact on emulsion stability, except for brine composition and toluene insolubles, which had little impact on emulsion stability in this study. Operationally speaking, because it was found that the emulsion was stabilized by multiple factors, multiple preventative approaches are required to sustain stable production, free of emulsion. Oil Water Emulsion Fig. 1-Photograph of the fluid sample collected from the water tank (left) and microscopic view of the emulsion phase (right).
There is a wide range of scientific literature related to emulsion stability, most of them dealt with water - in - oil (W/O) or oil - in - water (O/W) type. The present work is ai med to investigate the stability mechanisms of water - in - crude oil emulsion stabilized by a non - ionic emulsifier (Span 80). The blending of (50 - 50 vol. %) heavy and light crude oil was first characterized in terms of physico - chemical properties. The emulsio n was stabilized by (1.5 and 2.5 vol. %) emulsifier at different water: oil ratio of (20 - 80 vol. %) and (40 - 60 vol. %). According to the result of microscopy images, the steric stability was obtained in low water volume fraction content (20%), with the sma ller droplet sizes and at higher surfactant concentration (2.5%). The emulsions stabilized with Span 80 obtained a visually stable emulsion in both concentrations of emulsifier and volume fractions of dispersed phase (water) in a period of one week, and th ere was no water separation was observed in this period. To determine the dynamic viscosity rate, the temperature was varied from 30 ºC to 90 ºC and shear rate from (17 to 85)1/sec respectively. Moreover, the emulsion with the higher water volume fraction (40%) and emulsifier concentration of 2.5 % indicated higher dynamic viscosity. However, in all types of the samples, the dynamic viscosity decreased by increasing the shear rate. The results obtained in this study have exposed the capability of the chosen emulsifier as another promising method for stabilizing w/o emulsions. Further works are, nevertheless, required to provide deeper understanding of the mechanisms involved to facilitate the development of an optimum system applicable to the industry.
Journal of Chemical and Petroleum Engineering, 2020
Water in oil emulsion is considered as one of the major challenges encountered during the production of heavy oil or applying enhanced oil recovery techniques whether thermal or chemical. In this study, the stability and rheological properties of hot and cold-produced heavy oil emulsions, formed due to steam injection processes in Kuwaiti reservoirs, were investigated thoroughly over a wide range of operation conditions. The effects of temperature, shear rates, and water cuts on the physical and chemical behaviors of the heavy oil emulsions were examined experimentally in detail. The results showed that the cold-produced heavy oil emulsion (CP-HO) is more stable than the hot produced heavy oil emulsions (HP-HO) because of its high salinity concentrations and low resin/asphaltene (R/A) ratios, and low PH value. Moreover, a new emulsion viscosity correlation was developed using the experimental data. The proposed model was validated against existing models. The results showed that the developed correlation i is more applicable than the existed one in predicting the viscosity of heavy oil emulsions with a percentage of the deviation of almost less than 5%.
Rheologica Acta, 2008
Water-in-oil type emulsions can be formed during the crude oil production process. The presence of natural surfactants in oil (asphaltenes, resins) and mechanical stirring (piping/well system) produce emulsions, the stability and rheological behaviour of which depend mainly on the chemical composition of the oil and the internal phase concentration. In this work, water (brine 8 g NaCl/cm3) in oil (crude oil) emulsions were prepared and characterised by varying the internal phase concentration (5–80%). Rheological properties are discussed according to the composition of the oil and the temperature of the system. Relative viscosity was modelled following the classical models of Mooney and Krieger and Dougherty, but the best-fitting model for the experimental results was found with an exponential type equation between relative viscosity and volume fraction, as proposed by Richardson. Moreover, we observed that the plastic behaviour determined through the yield stress determination depended not only on the internal phase concentration but also on the temperature. Quantitative analysis of the emulsions’ viscoelastic parameters (storage and loss modulus) was made. In the case of concentrated emulsions (containing over 70% of internal phase), Princen’s theory of the high internal phase ratio emulsions (HIPRES) was verified.
Characterization Of Crude Oil Emulsion
2012
Crude oil emulsification happens at all stages of crude oil production and processing creating operational problems such as pressure drops in flow lines, corrosion, catalyst poisoning, increase in demulsifier usage and trips in crude oil handling facilities. In order to demulsify the crude oil aptly in-depth analysis of the characteristics of the crude oil is inevitable. This report presents the findings of a series of experiments performed to analyze the oil/ water separation in the presence of varying amounts and types of brine and emulsifiers respectively by using crude oil /water ratios of 70/30, 80/20 and 90/10. The results show the existence of an optimal salinity at which full or partial separation can be achieved without utilizing demulsifiers which can reduce considerable amounts of costs in terms of demulsifiers and other techniques for separation. v
Effect of the Type of the Oil Phase on Stability of Highly Concentrated Water-in-Oil Emulsions
Коллоидный журнал, 2013
The water in oil high internal phase emulsions were the subject of the study. The emulsions con sisted of a super cooled aqueous solution of inorganic salt as a dispersed phase and industrial grade oil as a continuous phase. The influence of the industrial grade oil type on a water in oil high internal phase emul sion stability was investigated. The stability of emulsions was considered in terms of the crystallization of the dispersed phase droplets (that are super cooled aqueous salt solution) during ageing. The oils were divided into groups: one that highlighted the effect of oil/aqueous phase interfacial tension and another that investi gated the effect of oil viscosity on the emulsion rheological properties and shelf life. For a given set of exper imental conditions the influence of oil viscosity for the emulsion stability as well as the oil/aqueous interfacial tension plays an important role. Within the frames of our experiment it was found that there are oil types char acterized by optimal parameters: oil/aqueous phase interfacial tension being in the region of 19-24 mN/m and viscosity close to 3 mPa s; such oils produced the most stable high internal phase emulsions. It was assumed that the oil with optimal parameters kept the critical micelle concentration and surfactant diffusion rate at optimal levels allowing the formation of a strong emulsifier layer at the interface and at the same time creating enough emulsifier micelles in the inter droplet layer to prevent the droplet crystallization.