Morphological evolution of thick wax deposits during aging

Evaluation of Wax Deposition and Its Control During Production of Alaska North Slope Oils

“…Thus, precipitation, though an important condition for deposition, is not necessarily sufficient for wax deposition. Singh et al (2001) reported that there are two stages or steps that are involved in wax deposition: wax gel formation followed by aging of deposited wax gel. Petroleum wax deposits contain some crude oil, water, gums, resins, sand, and asphaltenes, depending on the nature of the particular crude oil, which are entrapped during the crystallization and deposition process.…”

“…It is known that aromatics serve as solvents for high molecular weight saturates, which are the sources of paraffin waxes in crude oil while the polar components, especially asphaltenes, induce wax nucleation (Hammami et al, 1999). Singh et al (2001) reported, however, that the solubility of paraffins in aromatic, naphthenic, and other organic solvents becomes low at room temperature (low temperatures). Light ends of saturates equally help to keep the high molecular weight heavy ends in solution.…”

Effect of Oil Temperature on the Wax Deposition of Crude Oil With Composition Analysis

“…Various mechanisms have been proposed during the past decades, including molecular diffusion, shear dispersion, gravity settling, Brownian diffusion, etc. Molecular diffusion and aging effects have been supported as the predominant mechanisms, which clearly explain the flow rate effect and enrichment of heavy components in the deposit with time (Singh et al, 2000;Singh et al, 2001;Hernandez et al, 2004).…”

Rheological Investigation on the Effect of Shear and Time Dependent Behavior of Waxy Crude Oil

“…These solid crystals will adhere to the cold surface of the pipeline walls, which is normally at the lowest temperature compared to the core of the pipeline. This radial temperature gradient results in the wax mass flux towards the wall of the pipelines [4]. If no mitigation strategies are taken to increase the pipeline temperature, the paraffin deposits will further thicken over time reducing the diameter of the pipeline, throughput and the flow efficiency.…”