Demulsification techniques of water-in-oil and oil-in-water emulsions in petroleum industry

With the ever increasing demand for energy to meet the needs of growth in population and improvement in the living standards in particular in developing countries, the abundant unconventional oil reserves (about 70% of total world oil), such as heavy oil, oil/tar sands and shale oil, are playing an increasingly important role in securing global energy supply. Compared with the conventional reserves unconventional oil reserves are characterized by extremely high viscosity and density, combined with complex chemistry. As a result, petroleum production from unconventional oil reserves is much more difficult and costly with more serious environmental impacts. As a key underpinning science, understanding the interfacial phenomena involved in unconventional petroleum production, such as oil liberation from host rocks, oil–water emulsions and demulsification, is critical for developing novel processes to improve oil production while reducing GHG emission and other environmental impacts at a lower operating cost. In the past decade, significant efforts and advances have been made in applying the principles of interfacial sciences to better understand complex unconventional oil-systems, while many environmental and production challenges remain. In this critical review, the recent research findings and progress in the interfacial sciences related to unconventional petroleum production are critically reviewed. In particular, the chemistry of unconventional oils, liberation mechanisms of oil from host rocks and mechanisms of emulsion stability and destabilization in unconventional oil production systems are discussed in detail. This review also seeks to summarize the current state-of-the-art characterization techniques and brings forward the challenges and opportunities for future research in this important field of physical chemistry and petroleum.

Interfacial sciences in unconventional petroleum production: from fundamentals to applications

Carboxyl asphaltene is commonly discussed in the petroleum industry. In most conditions, electroneutral carboxyl asphaltene molecules can be deprotonated to become carboxylate asphaltenes. Both in crude oil and at the oil/water interface, the characteristics of anionic carboxylate asphaltenes are different than those of the carboxyl asphaltenes. In this paper, molecular dynamics (MD) simulations are utilized to study the structural features of different asphaltene molecules, namely, C5 Pe and anionic C5 Pe, at the molecular level. In crude oil, the electroneutral C5 Pe molecules prefer to form a steady face-to-face stacking, while the anionic C5 Pe molecules are inclined to form face-to-face stacking and T-shaped II stacking because of the repulsion of the anionic headgroups. Anionic C5 Pe has a distinct affinity to the oil/water interface during the simulation, while the C5 Pe molecules persist in the crude oil domain. A three-stage model of anionic C5 Pe molecules adsorbed at the oil/water interface is ...

Molecular Dynamics Simulation: The Behavior of Asphaltene in Crude Oil and at the Oil/Water Interface

Mechanisms, performance optimization and new developments in demulsification processes for oil and gas applications

At present, many petroleum copmpanies in the world are facing processing problems about crude oil extraction, production and refining. For example, conventional pipelines are not suitable for pipelining of extra heavy oils and bitumen from the reservoirs to the refineries. According to the aforesaid, a procedure was developed for the formation of an oil-in-water emulsion employing a Mexican crude oil and its subsequent phase separation as a strategy for the pipelining of extra heavy crude oils. An O/W emulsion considerably decrease the viscosity of an extra heavy crude oil and facilitating its transport through pipelines, but crude oil must be dehydrated before further processing. We carried out a screening of commercial and synthetic surfactants for emulsion preparation as well as for breakage. The emulsion was characterized by calorimetry, optical techniques, particle size and dynamic viscosity. The stability of emulsions was evaluated by the kinetics of water separation in the presence of surfactants and heating. We also developed a factorial 2k design to study emulsion breakage with factors such as temperature, surfactant concentration and pH. All surfactants developed by ours are low toxic and full biodegradable since they atre synthesized from glucose and glycine, respectively. Thus, we developed an environmental friendly approach to facilitate crude oil transport through pipelines.

Study of the formation and breaking of extra-heavy-crude-oil-in-water emulsions—A proposed strategy for transporting extra heavy crude oils

The objective is to understand the effects of organic acid and amine additives on the performance of commercial demulsifiers in breaking water-in-crude-oil (W/O) emulsions, according to the proportional regime test developed in previous articles. Both hydrophilic (ethylamine and acetic acid) and hydrophobic (hexanoic acid and hexylamine) species were tested, and all were found to exhibit different effects. The water-soluble species have essentially no effect, despite a change in aqueous phase pH. Hexanoic acid was found to increase the stability of the W/O emulsions, whereas the hexylamine was found to reduce it. Explanations of the effect of these additives on the interfacial formulation are proposed.

Breaking of Water-in-Crude Oil Emulsions. 5. Effect of Acid-Alkaline Additives on the Performance of Chemical Demulsifiers

Preparation and characterization of cellulose fibers from Meghatyrsus maximus: Applications in its chemical derivatives.

Following the studies about the behavior of the different fractions of the crude in the adsorption process, stud y of adsorption of models molecules onto silica‐asphaltene complex using adsorption isotherms was proposed. Benzoic acid was the model molecule used which is aromatic and an acid polar group. The used technique was the UV‐ Visible spectrophotometric to wavelength of 274 nm. Differences in adsorption behavior in the adsorption isotherms were attributable to the differences in the surfaces of the silica‐asphaltenes complex.

Con el fin de continuar elucidando el comportamiento de las di ferentes fracciones de los crudos en los procesos de adsorcion, proponemos hacer estudios de adsorcion de moleculas modelos sobre complejos s´ ilice-asfaltenos (SAC) utilizando isotermas de adsorcion. En esta investigacion se va a utilizar el ´

Iris Silva

Papers

Breaking of Water-in-Crude Oil Emulsions. 5. Effect of Acid-Alkaline Additives on the Performance of Chemical Demulsifiers

Preparation and characterization of cellulose fibers from Meghatyrsus maximus: Applications in its chemical derivatives.