Monday, November 9, 2015
Ballroom F (Salt Palace Convention Center)
Solid deposition from crude oil, especially asphaltenes, is well known as a cause of production interruption and various other operational problems in oil production. Asphaltenes are typically stable within reservoir, however may become destabilized and precipitate from crude oil, and deposit in near-wellbore porous media or on the internal surface of equipment (e.g. pipeline). Pressure and temperature play important roles in such asphaltenes precipitation and deposition. Spatial confinement in the porous structure near wellbore also has a large effect on the flocculation of asphaltenes. These factors were often investigated individually but the interplay between them is not well explained yet, hence there is a great need to study asphaltene particle aggregation and deposition behaviors in micro-scale structures at near-wellbore conditions. Here, we demonstrate preliminary results of asphaltene particle aggregation and deposition experiment using porous microfluidic channel at elevated pressure/temperature resembling near-wellbore conditions. Porous microfluidic channels are fabricated using glass/photopolymer to represent different surface wettability, and a pore-network pattern is chosen to represent typical porous structure. Various oil samples are tested through depressurization from 1000 psi to 500 psi, and the pressure-induced asphaltene precipitation will be compared with solvent-induced asphaltene in previous experiments. Flow experiments through the microfluidic channel are carried out and the asphaltene particle deposition rate & pattern with respect to thermodynamic parameters and flow conditions are discussed. These experiments can provide useful information for fundamental flow assurance research at wellbore conditions and aid the development of effective chemical inhibitors for remediation of asphaltene problems.