Development of Multifunctional Formulations for Inhibition of Waxes and Asphaltenes Deposition

Abstract

The development of formulations that solve at least two problems simultaneously (called multifunction or combo formulations) is very useful. In this study, different formulations were prepared in an attempt to find one that could act at the same time to inhibit deposition of waxes and asphaltenes. Formulations were prepared containing EVA 33 and one of the additives for asphaltenes dispersion (dodecylbenzenesulfonic acid, cardanol and two commercial products called INH1 and INH2), at various concentrations. The results showed that none of the asphaltenes stabilizers exhibited any influence on the performance of EVA33. Nevertheless, the EVA33 affected slightly the performance of the asphaltenes stabilizers. The formulations containing cardanol and EVA 33 performed better at inhibiting deposition of both asphaltenes and waxes than the other formulations did.

Direct Assessment of Inhibitor and Solvent Effects on the Deposition Mechanism of Asphaltenes in a Brazilian Crude Oil

“…For the systems with DBSA, some black spots related to asphaltene deposits appear earlier than for the other systems (see Figures S4 and S5 of the Supporting Information), agreeing with the lower onset for heptane-induced asphaltene precipitation determined with this additive (see Table S1 of the Supporting Information). The decrease in the onset using DBSA as an additive, although unusual, has already been reported in the literature, describing that this value could increase or decrease by changing the concentration of the inhibitor …”

Wax Precipitation Temperature Measurements Revisited: The Role of the Degree of Sample Confinement

“…To circumvent this issue and avoid significant supercooling effects, modern microcalorimeters can be used instead of conventional DSC instruments. ,, These instruments possess higher resolution and have been associated with better calorimetric sensitivity than conventional DSC equipment, allowing for the possibility of using lower cooling rates without compromising sensitivity and/or a greater sample mass. , …”

“…Microcalorimetry has been reported to be more sensitive for detecting the onset of wax crystallization than conventional calorimetry. , Thus, by detecting crystallization peaks that would otherwise not be revealed, more accurate calculations of the total wax content in crude oils A1 and A2 can be made. This, in turn, can be done by using an average value of 200 J g –1 for the enthalpy of paraffin crystallization ( Δ H wax ) …”

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“…Wax dispersion improves oil flowability because the wax crystals cannot form large oil-occluding networks. The aromatic groups of the additive molecule may also facilitate wax solubilization in the oil and promote favorable interaction between waxes and asphaltenes and resins, which have an important influence on wax stability [43][44][45]. Based on the wax dispersal effect of the PPDs, the depreciation in PPD activity at treat rates above the optimal dosage is likely due to the high concentration of free (unadsorbed) additive molecules in the oil at these dosages.…”