Asphaltene Deposition in Different Depositing Environments: Part 1. Model Oil

Abstract

Among the asphaltene flow assurance issues, the most major concern because of asphaltene is its potential to deposit in reservoir, well tubing, flow lines, separators, and other systems along production lines causing significant production losses. Hence, the focus of this study is to understand the depositional tendency of asphaltene using quartz crystal microbalance with dissipation (QCM–D) measurements. The results are presented in two consecutive papers, with this paper (part 1) dealing with model oil systems. The depositing environment is varied by changing the system temperature, asphaltene polydispersity, solvent (asphaltene stability), depositing surface, and flow rate. This paper also discusses the roles of convective, diffusive, and adsorption kinetics on asphaltene deposition by modeling the adsorbed mass before asphaltene precipitation onset. The successive paper (part 2; 10.1021/ef401868d) will deal with real crude oil systems and modeling of the deposited mass after asphaltene precipitation onset.

Determining the Kinetics of Asphaltene Adsorption from Toluene: A New Reaction–Diffusion Model

“…second order model provided a good fit for the experimental data whilst the pseudo-first order model did 21 not. The equilibrium adsorbed masses obtained by the pseudo-second order model were in good 22 agreement with the experimentally measured values (R² = 1.0).…”

“…The QCM-D technique has been explained in detail by others previously [21,23,25,26]. In this work, the 14 adsorption of asphaltene from solution in toluene onto a gold-coated quartz sensor was investigated 15…”

“…The quartz crystal microbalance (QCM) has proven a useful technique for investigating the adsorption 34 and deposition of asphaltene onto solid surfaces [20][21][22][23][24][25]. It is also being adapted to investigate 35 asphaltene deposition under extreme conditions.…”

“…Tavakoli et al used QCM-D to research adsorption from extracted asphaltene [21] and crude oil [22] in 9…”

On the use of nanomechanical atomic force microscopy to characterise oil-exposed surfaces

“…Understanding the nature of these deposits and their interaction with the relevant surfaces is the rst step towards being able to mitigate against them. A wide variety of characterisation techniques have been employed in recent years [1][2][3][4][5][6][7][8][9] to explore these deposits including electron microscopy and spectroscopy, infra-red spectroscopy, QCM and AFM.…”