This paper presents the results of an experimental study of paraffin deposition under single-phase turbulent flow conditions. Two different fluids – South Pelto crude oil, and Garden Banks condensate – were used to conduct this experimental study on a small scale facility in TUPDP (Tulsa University of Paraffin Deposition Projects). Flow loop deposition data with the crude oils are analyzed and presented. Correlating parameters for paraffin deposition are also discussed under turbulent flow conditions in this paper. When oil temperature falls below the wax appearance temperature during oil transportation, paraffin molecules reach the wall or the interface of the oil and deposit. They crystallize and become a part of the deposit. This phenomenon is known as paraffin deposition which is one of the key flow assurance issues in oil industry. In this study South Pelto oil, and Garden Banks condensate, having paraffinic nature, were studied using the small scale facility. Both short term and long term experiments were conducted. Behavior of various parameters such as deposit thickness, wax content, and deposit wax mass were investigated with respect to flow characteristics: namely, wall shear stress, Reynolds number, and radial temperature gradient. It was observed that paraffin deposition is not only dependent on the thermal driving force which is the temperature difference between oil bulk and initial inner pipe wall but also on turbulence effects. It was experimentally shown that flow turbulence and radial temperature gradient have a significant impact on the deposition process. The experimental results presented in this paper can be used to validate paraffin deposition models and to develop correlations that take the effects of turbulence on paraffin deposition into consideration.
During oil transportation, when oil temperature falls below the wax appearance temperature, higher molecular weight aliphatic components (n-paraffins) will solidify and precipitate out of solution.