Effect of poly (ethylene-butene) and nano-aluminium oxide blend on the viscosity of Nigerian crude oil

Abstract

Wax deposition in production tubing and pipelines is very critical in Nigeria petroleum industry. It can lead to a reduction in production, shut-in of wells, choking of flow lines, failure of downhole equipment, increased power requirement and loss in revenue. In the bid to address this issue, a Niger Delta crude oil sample was characterized in this study to know its wax deposition tendency and other chemical properties. The effect of temperature on the viscosity of the crude oil sample was studied, and the degree of viscosity reduction (DVR) of the crude oil sample in the presence of poly (ethylene-butene) (PEB) and nano-aluminium oxide (Al2O3) blend at different temperatures was evaluated. 100 ppm of nano-Al2O3 blend with 1000 ppm, 2000 ppm and 5000 ppm of PEB, respectively, was added to the crude oil sample at different temperatures, and the degree of viscosity reduction (DVR) in each blend at 10 °C, 15 °C, 20 °C, 30 °C and 35 °C was evaluated. The blend with 2000 ppm of PEB with 100 ppm nano-Al2O3 is the best for offshore application as it gave the highest DVR of 77.9% and 73.7% at 10 °C and 15 °C, respectively, while the other blends gave a DVR of about 70% at 10 °C and 15 °C. As the crude sample temperature approached the wax appearance temperature of 29 °C, the DVR of PEB/Al2O3 blend drastically reduced. PEB/Al2O3 blend inhibited wax precipitation, and at low temperatures, a significant reduction in the viscosity of the crude oil sample was observed, which makes it a good recommendation for offshore application.

Synthesis, characterization and evaluation of stearyl acrylate-co-behenyl acrylate copolymer as a pour point depressant of waxy crude oil

“…This is due to a rise in temperature that dissolves the wax paraffin, which remains as a liquid, consequently reducing the viscosity of crude oil. In comparison, a reduction in temperature of fluid leads to wax precipitation and increases viscosity (Kumar et al 2018;Odutola and Idemili 2020;Taborda et al 2016). The fluid viscosity reduces at 15, 20, 25 and 30 °C as binding energy reduces due to a decrease in the cohesive forces of the molecular compositions.…”

“…In addition, crude oil's rheological behavior is typically non-Newtonian under WAT, which supports the fact that crude oil's kinematic viscosity rises below WAT. As crude oil temperature falls, the molecules of wax started to deposit out of fluid and shape a complex, three-dimensional wax structure that gradually binds the lighter components of crude oil, thereby reducing crude oil flowability (Odutola and Idemili 2020;Subramanie et al 2020).…”

“…The finding exhibited that MA and EVA were capable of reducing the crude oil viscosity by 86.4% and 88.0%, respectively, while the addition of Sodium cloisite Na + to both MA and EVA reduced the viscosity by about 89.2% and 94%, respectively (Subramanie et al 2020). Odutola and Idemili (2020) studied the impact of different concentrations of Poly (ethylene-co-butene) (PEB) blend with nanoparticles of aluminum oxide (Al 2 O 3 ) at 100 ppm of concentration in Niger delta crude oil. The results revealed that PEB copolymer at 2000 ppm combined with aluminum oxide at 100 ppm demonstrated the highest performance for offshore applications with viscosity reductions of 77.9% at 10 °C and 73.7% at 15 °C.…”

“…The PPD is also known either as wax crystal modifier or flow improver, which are compounds of polymeric that have formed by a series of hydrocarbons that supply the interaction between the wax inhibitor PPD and wax paraffin and act to change the morphology of crystal. Due to the significant role of PPDs in oil production and transportation, several PPDs were synthesized and evaluated on waxy crude oil, such as copolymer of ethylene-co-vinyl acetate (EVA) (Machado et al 2001;Tu et al 2017), poly of octadecyl acrylate (POA) polymer (Handayani et al 2019;Yang et al 2018;Yang et al 2015a, b;Zhu et al 2004), poly of alkyl acrylate (Feng et al 2014;Litvinets et al 2016), poly of dodecyl methacrylate-co-vinyl acetate (Ghosh et al 2017), poly of glycidyl methacrylateco-octadecyl methacrylate (Goswami et al 2019), poly of methacrylate-co-maleic anhydride (Xu et al 2018) poly of methylsilsesquioxane (PMSQ) microsphere (Yang et al 2017), poly of maleic anhydride -co-alkyl linoleate (Soliman et al 2018), terpolymer of alkyl acrylate-co-vinyl acetate-co-maleic anhydride (Feng et al 2014) poly of stearyl acrylate-co-behenyl acrylate (SABA) copolymer (Elarbe et al 2021), poly of fatty esters-co-succinic anhydride (Deka et al 2020), poly of ethylene-co-butene with nano-aluminum oxide blend (Odutola and Idemili 2020) poly of benzyl methacrylate-co-methacrylate (Xie et al 2019) and terpolymer of benhely acrylate-co-stearyl methacrylate-co-maleic anhydride (Elganidi et al 2020). These studies have a strong influence on the viscosity reduction which can improve the performance of the flowability and inhibit the deposition of wax.…”

“…The results revealed that PEB copolymer at 2000 ppm combined with aluminum oxide at 100 ppm demonstrated the highest performance for offshore applications with viscosity reductions of 77.9% at 10 °C and 73.7% at 15 °C. (Odutola and Idemili 2020). Yang et al (2015a, b) have been examined the effect of poly octadecyl acrylate as polymer (POA) combination with the SiO 2 nanoparticle on the fluid properties.…”