Enhanced sedimentation and coalescence of petroleum crude oil emulsions by the new generation of environmentally friendly yellow chemicals

Abstract

The purpose of this study was to compare the efficiency of new chemistry yellow demulsifiers with already commercially available yellow demulsifiers in destabilizing two types of systems: petroleum crude oil emulsions and model densely packed layers (DPL). Oil-water separation was measured by low field NMR, which allows monitoring the water content in emulsion as function of the sample height and the time. Separation profiles measured by NMR depicted an increase of the free water release kinetic as the concentration of demulsifier increased, as well as the sedimentation velocity. There was no observation of DPL formation in the crude oil emulsions.4 different demulsifiers were tested on a model DPL and compared with normal crude oil emulsions. One chemical showed a higher efficiency in DPL than in crude oil emulsion. To gain more understanding on the destabilization mechanism, the interfacial rheology properties of the systems were determined. The interfacial experiments showed an increase on the elastic modulus (E'), therefore a stronger interface, as the concentration of demulsifier increased. The viscous modulus (E'') tend to reach a minimum value at low concentrations. There are differences on the experimental procedure for both techniques but the increment of the elastic modulus is not totally understood. The most important parameters were represented by Principal Component Analysis (PCA). PCA analysis did not contribute in a better characterization of the chemicals. The new generation of yellow demulsifiers has not reproduced the efficiency of commercially yellow available demulsifiers

Demulsification of Crude Oil Emulsions Tracked by Pulsed Field Gradient (PFG) Nuclear Magnetic Resonance (NMR). Part I: Chemical Demulsification

“…This is the opposite of what is observed in this study where the experimental sedimentation is higher than predicted from Stokes. Discrepancies between measurements and values calculated from Stokes' law has also been found in previous work 13 , where the results did not point to any relation between sedimentation rate and the square of the droplet radius, as indicated by Equation (1). a No uncertainty available as this was the only parallel for which sedimentation rate calculation was possible, as the first two brine profiles were not recorded.…”

“…A high degree of coalescence is also well correlated with its efficiencies (Fig. [13][14][15][16], and is the second best tested chemical amongst the four. Free water appearance time curves (Fig.…”

“…NMR procedures were also developed to measure the residual water content in the separated oil phase at the top after oilwater separation 31 . Studies have been performed with application of NMR on demulsification of crude oil emulsions by chemical demulsifiers 13 .…”

“…Understanding the flocculation kinetics is vital because it has a tendency to follow the changes in emulsion properties, and usually precedes droplet coalescence . Barrabino et al referred to the possibility of droplet interaction as an important factor that enhances droplet settling during demulsification in his experiments. Efficiency of a demulsifier, in a water-in-crude oil emulsion, has been shown to be dependent on the crude oil type, pH of the aqueous phase, salinity, and temperature .…”

Modelo matemático estocástico para diagnosticar calidad de agua y sedimentos en zonas influenciadas por la actividad petrolera en la provincia de Orellana.

“…La presencia excesiva de contaminantes debido a las actividades extractivas, modelos de transportes, generación de energía y actividades cotidianas producen contaminantes que son transportados por las corrientes de aire y son depositados en cuerpos de agua (Owa, 2013). Índice de calidad del agua es un número que determina las características del agua por la combinación de ocho variables para dar a conocer un métodos simple y veraz (Barrabino et al, 2017).…”