Forecasting Asphalt-Resin-Paraffin Deposition: Rheological Analysis and Transition Temperature Determination

The formation of asphalt-resin-paraffin (ARP) deposits in oilfield gathering systems is a major operational challenge, particularly during the final stages of field development when temperature and pressure variations intensify structural changes in crude oils. These deposits significantly increase hydraulic resistance, reduce well productivity, and complicate transportation processes. This study addresses the need for a rapid and reliable method to predict the transition temperature at which structural formation begins in rheologically complex oils containing paraffin, resin, and asphaltene compounds. Laboratory investigations were conducted on crude oils from Azerbaijan’s offshore fields-specifically Bulla-Deniz (Well No. 89) and Alat-Deniz (Well No. 64)-as well as their mixtures and commercial variants. Rheological parameters-shear stress (τ) and dynamic viscosity (μ)-were measured using a “Reotest-2” rotational viscometer at temperatures ranging from -10 °C to 50 °C and various shear rates. The experimental data were processed using a double logarithmic transformation to construct ln(lnμ) = f(t) dependencies, enabling the determination of the transition temperature through the intersection of linear segments. Results indicate that the proposed graph-analytical method provides accurate predictions of structural formation temperature, which coincides with values obtained experimentally. The developed diagnostic approach allows for timely identification of critical temperature ranges during oil extraction and transportation, facilitating preventive measures against ARP deposition. This method offers practical applicability for optimizing oilfield operations and reducing maintenance costs associated with paraffin-related complications.