Mês: março 2024

by Vanessa Guersoni, Charlie Van Der Geest, Antonio Carlos Bannwart, Ivanei Ferreira Pinheiro, presented at Rio Oil & Gas 2022, September 2022.

Abstract

The intrinsic characteristics of crude oils, combined with the pressure and low temperature of the seabed, can lead to flow assurance problems, compromising production. The low temperature causes a decrease in the wax solubility, eventually reaching the wax appearance temperature (WAT). Precipitated crystals can cause deposition on the tube walls and can affect production as they increase the pressure drop, decreasing flow during production. Depending on molecular weight, molecular structure and carbon number distribution, waxes can be called macrocrystalline and microcrystalline. Macrocrystalline wax mainly has a carbon number distribution of approximately C20 to C40 and has a linear molecular structure, so hydrocarbons tend to form large plates. Microcrystalline wax generally has chains with carbon numbers between C30 to C70 and its crystals tend to form smaller crystals. In the present work, the impact on gel strength was evaluated as a function of wax type (macrostructure and microstructure), wax concentration and applied shear rate. Understanding these impacts makes it possible to improve the models of wax deposition and, consequently,
the methods of preventing and mitigating the phenomenon.

 

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by Tatiana Marques Pessanha, Vanessa Guersoni, Carlos Eduardo Perles, Antonio Carlos Bannwart, presented at Rio Oil & Gas 2022, September 2022.

Abstract

This work aims to understand the phenomenon of coalescence as a function of chemical and rheological characteristics (elasticity and viscosity) of the interfacial film. In this context, the goal is to study the effect of the different physicochemical variables related to emulsion and its influence on the energy barrier that separates the droplets from the isolated state to coalescence. For this, a pendant drop tensiometer was used to determine the coalescence time between the oil droplet and the oil-water interface, using commercial surfactants to establish a correlation of how the physicochemical characteristics of the interfacial film will influence the coalescence time between the he oil droplet and the oil-water interface .The preliminary results show that the brine concentration and the ion types present in brine impact directly on the coalescence time, due to changes on interfacial film properties, promoting a barrier to coalescence, and modification on mechanism of interactions of these systems.

 

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by Rodolfo Marcilli Perissinotto, William Denner Pires Fonseca, William Monte Verde, Jorge Luiz Biazussi, Rafael Franklin Lazaro de Cerqueira, Marcelo Souza Castro, Antonio Carlos Bannwart, presented at Rio Oil & Gas 2022, September 2022.

Abstract

The presence of emulsions in centrifugal pumps has always been a top issue for oil and gas exploration companies. These oil-water mixtures cause financial losses along the production chain, as they often induce pumps to operate in an unstable and inefficient manner. As there is a clear dependence between the pump performance and the flow arrangement in the impellers, this current paper aims to broaden the understanding on the behavior of emulsions inside the stage of a centrifugal pump. Thus, the paper describes the design and fabrication of a new transparent pump prototype for visualization purposes focused on academic studies. The new prototype is completely transparent, so it enables visual access and light entrance from the front and sides. Besides, the new pump is able to operate with twophase flows, since the dispersed phase can be injected directly into the impeller channels, through the shaft. Some tests were then conducted with this new prototype. They provided successful results which are presented and discussed here. Therefore, the new transparent prototype is an innovative alternative to help engineers and researchers investigate twophase flows in rotating and stationary pump parts.

 

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by Viviane Karcher, Tayanne Santos Ligeiro, Ivanei Ferreira Pinheiro, Letícia Bizarre, Charlie Van Der Geest, Vanessa Guersoni, Antonio Carlos Bannwart, presented at Rio Oil & Gas 2022, September 2022.

Abstract

Petroleum is a complex mixture of hydrocarbons varying from saturate, resins, asphaltenes and aromatics. Wax, also known as paraffin, normally refers to the range of n-alkanes in the crude oil with carbon numbers higher than 18. The waxes present in crude oils are divided into two categories: macrocrystalline wax, tends to form large plate-like crystals and, microcrystalline, tends to form solids with a lower degree of crystallinity. It has not been possible to establish a pattern that links the tendency of type of solvent and type of paraffin, due to the complexity of the wax crystal morphology. The objective of this research is to study the thermal properties of macro and microcrystalline paraffin under solubilization of several solvents through experimental techniques of DSC (Differential Scanning Calorimetry) and CPM (Cross Polarized Microscopy). The interaction of each type of n-paraffin in different solvents causes distinct influences on the crystal morphology and, consequently, influences on their thermal behavior. This study is relevant since elucidating this behavior helps to optimize deposition models and thus, define more effective mitigation resources in the problem of wax deposition.

 

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by Tatiana Marques Pessanha, Vanessa Guersoni, Carlos Eduardo Perles, Antonio Carlos Bannwart, presented at Rio Oil & Gas 2022, September 2022.

Abstract

The aim of this research project is to study how commercial emulsion breakers affect the interfacial properties of water/ oil systems. For that, the studies will be focused on the properties of the interface such as interfacial tension, dilational and shear viscoelastic behavior. The characteristics of the interfacial film will be analyzed along with the results from kinetic studies of phase separation with emulsion breakers. The tension and rheological studies of the interface will be performed by using a Spinning drop Tensiometer (Dataphysics SVT-20N) and an interfacial rheology accessory for a rotational rheometer (Haake, Mars III). Each rheological system aims to getting different properties of the interface. The dilational technique provides information about the response of the system when the interfacial area is changed, i.e., the kinetics in which the system acts to bring the interface back to the equilibrium condition. On the other side, in the shear technique the interfacial area is kept constant and the mechanical properties of the interface are probed. Emulsion breakers can act by affecting the viscoelastic properties of the interfacial film built up of crude oil components with surface active properties, such as asphaltenes, resins and naphtenic acids. Thus, the focus of this research proposal is to investigate how emulsion breakers acts on the formation and establishment of the interfacial film and the relationship between the film physic-chemical properties and the efficiency of the emulsion breaker, looking for a microscopic understanding of the phase separation phenomenon of water/ oil emulsions induced by emulsion breakers. (AU)

 

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