Formation Of Oil Emulsions Research Articles

Evaluation of the effectiveness of commercial demulsifiers based on polyoxyalkylated compounds in relation to oil and water emulsions of the Sarybulak oilfield

Water and oil emulsion formation is a natural process that takes place during oil recovery and processing. Heavy oils of Kazakhstan form highly stable oil emulsions mostly stabilized by a high content of asphaltenes, resins, and other surface-active components. Oil-in-water emulsions initiate the corrosion of equipment and cause transportation issues. Dewatering of oil emulsions is economically reasonable and requires universal techniques which could be applied to any sort of oil. In this study, the chemical composition of crude oil from the Sarybulak oilfield was determined, and commercial demulsifiers of Basorol brand were applied to these water-in-oil emulsions. The natural stabilizers content (asphaltenes and resins) was determined and correlated with IR-spectrum data. Finally, the effectiveness of demulsifiers is compared and explained according to their structures. It has been found that the higher the relative solubility number of the demulsifier, the better water-in-oil emulsion separation efficiency and dewatering mechanism was assumed. Results of water separation showed that Basorol PE-10400 and PE-10500 are the most effective, with DE of 96% and 91%, respectively, for 30% (vol.) water-in-oil emulsion at 60°C during 1-hour treatment.

INCREASING THE EFFICIENCY OF WELLS ACID TREATMENT BASED ON THE USE OF AN EMULE SUPPRESSING REAGENT

Background One of the problems in hydrochloric acid treatment of wells is the formation of oil emulsions with active and neutralized acid solutions. The formation of oil-acid emulsions leads to numerous complications, which include an increase in the pressure of acid injection into the reservoir, a deterioration in the removal of waste reaction products, a slowdown in the development of a well, etc. There is a need to obtain such compositions of acid solutions that do not form or reduce the formation of oil-acid emulsions. Aims and Objectives In order to suppress oil-acid emulsions, it was proposed to add the EROA reagent to the acid composition. Before using the upgraded composition of the acid solution in the field, it is necessary to carry out studies to study the effect of the EROA reagent on emulsion formation. Results Experimental work has shown that the content of the EROA reagent in the acid composition makes it possible to effectively destroy the emulsion, while the optimal concentration of the EROA reagent in the acid solution is 0.2 wt%. The introduction of the EROA reagent in the field at 3 wells of the Arlanskoye field made it possible to reduce the acid injection pressure into the formation by 16 %, increase the oil productivity factors, and reduce the well development time.

Nanocellulose as an inhibitor of water-in-crude oil emulsion formation

Formation of water/oil emulsions is a frequent and challenging problem to deal with during crude oil extraction and processing. Crude oil must have water contents (BS&W) below 0,5% to meet transport and export requirements. Lowering BS&W values in crude oils involve physical and chemical processes or their combinations. Chemical demulsifiers, particularly, are structurally diverse and predominantly petrochemically-derived; however, alternative surface-active compounds such as biosurfactants are nowadays the topic of active research. In this contribution, we report the use of aqueous suspensions of cellulose nanoparticles, both nanocrystals (CNC) and nanofibrils (CNF), to inhibit the formation of w/o emulsions. HLB values of 13.0 for CNF and 10.7 for CNC indicate that these materials are hydrophilic o/w emulsifying agents, and as such can also act as destabilizers for w/o emulsions. We observe, by recovered water and Near-Infrared (NIR) scattering measurements, that CNC and CNF can effectively function as inhibitors of synthetic w/o and natural w/crude oil emulsions. Aqueous suspensions of CNC and CNF decrease the amount of emulsified water, inhibiting the formation of w/o emulsions up to 75% in some cases.

MODELLING NANO-TECHNOLOGICAL PROCESSES OF OIL EMULSIONS FORMATION AND DESTRUCTION

It is shown that oil preparation process is related to nanotechnologies, since they are carried out at the Nano-dimensional level consisting in the charge interaction of mono and polyvalent ions being present in interacting environments of oil and reservoir (intermediate) water. Taking into account specific features (Nano-phenomena) of oil emulsion formation and destruction, a mathematical model for thermochemical oil dehydration process is proposed. As it is known, the main processes of formation and destruction of AC at the interfacial section (oil-water) occur at the molecular level, and molecular-surface phenomena (Nano-phenomena) are dominant in the process of oil preparation. First of all, this is the charge interaction of nano-dimensional particles, manifested in the form of physicochemical adsorption of natural emulsifiers on the surface of EWD, wetting the armoring casings of the latter (with corresponding demulsifier interaction), ion-exchange formation of a double electric layer (DEL) on surfaces of EWD and mechanical impurities (solid particles of clay, quartz, limestone, dolomite, iron sulfide, etc.). Consequently, the modeling of these processes is an urgent task, and the article is dedicated to above-mentioned problem.

Modeling of Emulsion Formation and Breaking in Thermochemical Oil Treatment Process

Nanotechnology comprises oil treatment processes because they occur on the nano-scale and involve interaction of charged mono- and polyvalent ions found in the interacting oil and reservoir water A mathematical model for thermochemical dehydration of oil is proposed considering the specific features (nano-scale effects) of oil emulsion formation and breaking. Procedures for estimating the effectiveness of the intermediate emulsion layer and analytical expressions for determining the residence time of oil emulsions in settlers of thermochemical oil treatment facilities are proposed.

Experimental investigation of emulsified oil dispersion on bulk foam stability

Recently aqueous foams have shown promising results to overcome viscous fingering and gravity segregation problems during gas injection process. However, one of the main challenges is the stability of the foams in the presence of oil bank at the front of injected foam. Oil can penetrate into the foam structure in the form of continuous phase or emulsions which might deteriorate lamellae and plateau borders that can result in bubble coalescence and foam rupture. The combination of the surfactant solution, responsible for stabilizing foams, with oil increases the potential for the formation of oil emulsions. In this condition emulsions stability and phase behaviour have the main influence on the bulk foam stability. The objective of this research is to conduct a comprehensive study on the effect of emulsified oil, at different concentrations and salinities on the stability of bulk foams used during oil displacement processes. This was achieved using a foam column test, in which foam is generated and its decay monitored with time. The half-life for each sample was noted and a comparison was made for different cases. Furthermore, changes in the foam bubble sizes and distribution were observed and analysed using an image processing software. A gradual reduction in the half-life of foam was observed with increasing concentration of emulsified oil. The degree to which a foam structure is destabilized by the emulsified oil droplets is dependent on the type and concentration of surfactant employed in generating the foam. At 2 wt% concentration of emulsion, the half-life recorded for foam generated by AOS surfactant, was 107 min, while for the foam generated by SDBS was only 39 min. Further analysis of the results showed a reduction in the number of dispersed oil droplets with increasing the salinity. In addition, the effect of increased salinity of the emulsion on foam stability was again found to be a function of the type of the surfactant is present in the foam system.

Profiling of Indigenous Microbial Community Dynamics and Metabolic Activity During Enrichment in Molasses-Supplemented Crude Oil-Brine Mixtures for Improved Understanding of Microbial Enhanced Oil Recovery.

Anaerobic incubations using crude oil and brine from a North Sea reservoir were conducted to gain increased understanding of indigenous microbial community development, metabolite production, and the effects on the oil-brine system after addition of a complex carbon source, molasses, with or without nitrate to boost microbial growth. Growth of the indigenous microbes was stimulated by addition of molasses. Pyrosequencing showed that specifically Anaerobaculum, Petrotoga, and Methanothermococcus were enriched. Addition of nitrate favored the growth of Petrotoga over Anaerobaculum. The microbial growth caused changes in the crude oil-brine system: formation of oil emulsions, and reduction of interfacial tension (IFT). Reduction in IFT was associated with microbes being present at the oil-brine interphase. These findings suggest that stimulation of indigenous microbial growth by addition of molasses has potential as microbial enhanced oil recovery (MEOR) strategy in North Sea oil reservoirs.

Experimental Investigation of Nano-Biomaterial Applications for Heavy Oil Recovery in Shaly Porous Models: A Pore-Level Study

Application of nano or biomaterials for enhanced oil recovery (EOR) has been recently much attended by petroleum engineering researchers. However, how would be the displacement mechanisms and how would change the recovery efficiency while nano and biomaterials are used simultaneously is still an open question. To this end, a series of injection tests performed on micromodel containing shale strikes. Three types of biomaterials including biosurfactant, bioemulsifier, and biopolymer beside two types of nanoparticles including SiO2 and TiO2 at different concentrations were used as injection fluids. The microscopic as well as macroscopic efficiency of displacements were observed from analysis of images recorded during the tests. Microscopic observations revealed different mechanisms responsible for oil recovery including: wettability alteration, thinning oil film, interfacial tension (IFT) reduction, and water in oil emulsion formation. Contact angle experiments showed changes in the surface wetness from an oil-wet to neutral-wet/water-wet conditions when a layer of nano-biomaterial covered thin sections of a shaly sandstone. Also the results showed that the presence of shales causes early breakthrough and ultimate oil recovery reduction. Shales act as flow barriers and enhance injection fluid viscous fingering. Displacement efficiency in shaly systems is sharply related to the shale distribution. Oil recovery after breakthrough in shaly systems is progressive and considerable volume of oil in place is recovered after breakthrough. The highest efficiency, 78%, observed while injecting one pore volume of biopolymer and SiO2 nanoparticles. This work illustrates for the first time the mechanisms involved in nano-biomaterial-crude oil displacements.

An Experimental Investigation of Viscosity Reduction for Pipeline Transportation of Heavy and Extra-Heavy Crude Oils

Due to the increase in the world energy demand, the use of all hydrocarbon resources, especially heavy and extra heavy crude oils, is required. But transportation of these oils is very difficult due to their high viscosity and low mobility. There are many different methods to reduce heavy crude oils viscosity, such as heating, blending, water in oil emulsion formation, upgrading, and core annular flow. The authors aimed to investigate experimentally some of these methods for reduction of viscosity of two Iranian heavy crude oils. Naphtha, light crude, and kerosene were blended with the oils. Results show that heating decreases the viscosity very rapidly and naphtha is the best blend type that can decrease the viscosity of Soroosh and Nowrooz crude oils to 200 cp, which is the appropriate viscosity for pipeline transportation, by using 15 and 5 vol% of naphtha, respectively. Alternatively, emulsion formation was carried out using Triton X-100 as the emulsifying agent, and it was established that a practical level of reduction is achievable at 75–85 vol% oil content.

Functions of Demulsifiers in the Petroleum Industry

There are an increasing number of crude oil fields that are now producing both crude oil and water emulsions; such fields are both onshore and offshore. These emulsions are formed during oil exploitation due to the presence of natural surfactants, such as asphaltenes and resins. These molecules strongly stabilize the water/oil interface and prevent coalescence of water droplets. As water/oil phase separation is necessary before oil transportation and refining, demulsifiers are used to break water-in-oil emulsions. This review presents the crude oil emulsion formation, factors affecting demulsification of crude oil emulsion such as demulsifier chemical structure, water content, partition coefficient (KP), and demulsifier concentration. This review also covers the kinetics and mechanism of the demulsification process.

Silicone Oil Emulsification: Effects on Corneal Endothelial Permeability

AbstractThe effects of silicone oil emulsification were examined in a model system that consisted of 1 week of in vivo anterior chamber exposure to the stimulus followed by an in vitro examination of passive permeability of the corneal endothelium. Silicone oil alone caused a small, but significant increase in corneal endothelial permeability. Bovine serum albumin (BSA) was used to generate the emulsion and experiments were performed with pyrogen-poor BSA alone that had further been passed through an endotoxin filter. BSA alone caused a small increase in corneal endothelial dextran permeability while the BSA/oil combination caused substantial increases in both inulin and dextran permeability. The emulsion appears to result in a permeability that is a reflection of the addition of both oil and protein on the endothelium. No amplification or attenuation of the response to either individual component is seen. Two factors seem to play a predominant role in the formation of oil emulsions: the ionic strength of...