Effect of Comb-type Copolymers with Various Pendants on Flow Ability of Heavy Crude Oil

Abstract

Modification of the paraffin crystallization and flow ability of waxy crude oil is of vital importance during transportation and restart processes at low temperature. To investigate the influence of pendants in comb-type copolymers on the cold flow ability of crude oil, maleic anhydride-α-octadecene copolymer and its derivatives with octadecyl (MAC), phenyl (AMAC), or naphthalene (NMAC) pendants were synthesized. These derivatives, when added to waxy crude oil, change the size and quantity of the paraffin crystals observed by polarizing light microscopy (PLM), improve the flow ability of waxy oils by reducing the viscosity and yield stress revealed by rheometer, and decrease the paraffin crystallization temperature and quantity of wax precipitation determined by differential scanning calorimetry (DSC). AMAC had the greatest effect followed by MAC and NMAC, respectively. It seems that small aromatic pendants improve the flow ability of waxy oils by adsorbing on the surface of asphaltenes, while large aromatic pendants impair the assembly of copolymers with asphaltenes by a higher steric hindrance.

Investigation of inhibitors efficacy in wax deposition mitigation using a laboratory scale flow loop

“…The linear inhibitor can self‐assemble into micelle‐like aggregates providing a crystalline form and soluble hairy platelet structures that surround the core, and these structures can reduce the super‐saturation, delay the growth rate of wax crystals, and form abundant smaller wax crystals . The small wax crystal size can facilitate inhibition . If this is true, PI‐B and PI‐C may reduce the cohesive energy density more compared to PI‐A and can possibly form smaller crystals.…”

“…Certain wax inhibitors can serve as nucleating agents by self‐assembling or aggregation. The crystalline structures form numerous smaller wax crystals, as well as reduce the super‐saturation and growth rate of wax crystals . Inhibitors are favorably adsorbed on the surface of wax nuclei which forms a defective wax surface and will weaken interaction with the surrounding crystals .…”

A novel method for improving recovery of heavy oil reservoirs with high water cut based on polymer gel-assisted CO2 huff and puff

“…Therefore, its permeability was greatly reduced after the polymer gel was injected (Lai et al 2013). In addition, due to the presence of electrostatic and hydrogen bonds, the polymer gel would be adsorbed on the surface of the sand, which helped to improve the blocking strength and anti-erosion property of polymer gel (Xu et al 2015;Alcázar-Vara et al 2015;Cheraghian et al 2017;Pang et al 2015). As shown in Fig.…”

A Stochastic Model for the Fractal Dimension Estimation of Asphaltenes Aggregation

“…A way to explain their microscopic morphology is through fractal dimension and the diffusion-limited aggregation [14] that has been quite yet simulated [15]. Despite the knowledge acquired, formation condition, prevention, and overcoming of the formation while the liquid moves through a pipeline are some of the issues under study that must be understood [16]. According to the above, asphaltene molecules tend to group to form aggregates, which in turn tend to precipitate, causing several and expensive operational issues [17,18].…”