Evaluation of the Influence of a Chemical Inhibitor on Asphaltene Destabilization and Deposition Mechanisms under Atmospheric and Oil Production Conditions Using QCM and AFM Techniques

Abstract

An immersed quartz crystal resonator (QCR) was employed to assess the effectiveness of a modified alkylphenol resin in reducing asphaltene deposition on metal surfaces under various temperature and pressure conditions. The QCR response to asphaltene flocculation was first monitored during isothermal n-heptane titration experiments of dead crude oils with different contents of the asphaltene inhibitor (AI). In addition, the effect of the AI presence on the morphology of asphaltene deposits was analyzed by atomic force microscopy (AFM). Then, constant mass expansion experiments were carried out to determine whether the presence of the AI influenced the asphaltene instability pressure and the deposition rate of asphaltenes in a dead oil + CH4 system with various CH4 contents. The results of all these investigations in the nanometer range shed new light on the AI technology and clearly demonstrate that the presence of the AI can reduce the asphaltene deposition rate and modify the viscoelastic properties of the asphaltene solution in oil production conditions.

Breaking of Water-in-Crude Oil Emulsions. 10. Experimental Evidence from a Quartz Crystal Resonator Sensor and an Oscillating Spinning Drop Interfacial Rheometer

“…The study of asphaltene aggregation in cyclohexane with the QCR sensor was performed with a procedure similar to that used for the asphaltene destabilization study in previous works. ,,, A thickness shear resonator (AT-cut beveled quartz disk) with a nominal resonance frequency of 3 MHz, a blank diameter of 13.6 mm, and gold electrodes was fully immersed in pure cyclohexane inside a double-glass cell at a controlled temperature, as shown in Figure . A concentrated solution (2 wt %) of crude oil in cyclohexane was incorporated at a fixed rate (0.25 g min –1 ) onto the concentration cell, keeping a constant temperature of 25 °C.…”

“…Recently, the quartz crystal resonator (QCR or QCM) sensor has emerged as a suitable technique for the destabilization–aggregation–deposition process study of asphaltenes. − Among its advantages are its simplicity, versatility, and sensitivity. , This last one is a major attraction for its application in asphaltene aggregation studies because it can sense changes in the nanogram scale . Furthermore, although QCR is essentially considered a gravimetric sensor, it also responds to changes in the viscosity and density changes in the surrounding, thus making it ideal for detecting nanoaggregate transitions during the asphaltene destabilization/aggregation process when submerged in an asphaltene-containing oil phase. ,− Thus, it is a new technique to improve the understanding of the emulsion (de)­stabilization phenomena, particularly because only scarce examples are currently found in the literature.…”

Asphaltene Precipitation and the Influence of Dispersants and Inhibitors on Morphology Probed by AFM

“…Asphaltene aggregation and self-association (under favorable and unfavorable solubility conditions) have been extensively studied using multiple techniques (optical microscopy, UV-Vis spectroscopy, ultrasmall-, small-and wide-angle scattering, refractive index measurements, quartz crystal resonator (QCR) High Resolution Transmission Electron Microscopy (HRTEM)) [27][28][29][30][31][32][33], indicating that the governing forces driving this phenomenon are primarily of the Van der Waals type, Hydrogen bonding, acid-base interactions and π − π stacking [34][35][36]. The origin of these interactions is the nature of the asphaltene fraction, functionally defined in terms of solubility (soluble in aromatics but insoluble in n-alkanes) and the presence of multiple components (polyaromatic cores, metals, aliphatic chains, heteroatoms and functional groups such as hydroxyl, carbonyl, amine and nitrile, among others) that add to their molecular complexity [37][38][39].…”

Experimental Evaluation Method of Asphaltene Deposition Inhibitor’s Efficacity at Atmospheric Pressure Using a Fully Immersed Quartz Crystal Resonator, Centrifugation, and Optical Microscopy Techniques

“…However, its applications are not restricted to micro weighting as quartz sensors are sensitive to any change in its surrounding fluid when it is in contact with a fluid 35 or fully immersed in a liquid. 36 Therefore, it appeared to be particularly well suited to probe asphaltene destabilization by sensing both asphaltene mass deposition and bulk property changes. 37 The main objective of this work is to propose a multiscale set of laboratory tests for an efficient selection of chemical additives for asphaltene deposition reduction.…”

“…For this reason, it is also commonly referred to as a QCM (quartz crystal microbalance). However, its applications are not restricted to micro weighting as quartz sensors are sensitive to any change in its surrounding fluid when it is in contact with a fluid or fully immersed in a liquid . Therefore, it appeared to be particularly well suited to probe asphaltene destabilization by sensing both asphaltene mass deposition and bulk property changes …”