Development of Asphaltenes-Triggered Two-Layer Waxy Oil Gel Deposit under Laminar Flow: An Experimental Study

Abstract

In this work, we investigated the development of asphaltenes-triggered two-layer wax deposit with deposition time using an in-house wax deposition device, DSC, HTGC, SARA, and microscopic observation. For the pure waxy oil (Waxy Oil A), the formed wax deposit is a homogeneous and loose waxy oil gel. The wax deposit mass is relatively high and increases with increasing deposition time, while the wax appearance temperature (WAT), wax content, and ΔW of the wax deposit are relatively low and increase slowly with increasing deposition time. The critical carbon number (CCN) of the wax deposit is C24. The precipitated wax crystals (needlelike) in the wax deposit are liable to form a continuous network structure, which is adverse for the diffusion of wax molecules. The presence of asphaltenes in the pure waxy oil (Waxy Oils B–D) causes the formation of a two-layer wax deposit, which can be clearly characterized by the significant difference of structural strength. Different from the outer-layer wax deposit, the ...