Full text loading...
-
Fractal Analysis of Surface Roughness Induced by Asphaltene Deposits: Effect of Surface Topography on Wettability Altera
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, Shiraz 2009 - 1st EAGE International Petroleum Conference and Exhibition, May 2009, cp-125-00076
- ISBN: 978-90-73781-65-8
Abstract
Asphaltene precipitation is known as one of the side effects of gas injection in the depleted oil reservoirs. In this study surface topography alteration during high pressure precipitation process on different substrates (mica and glass) was studied. Fractal analysis of the surface images was performed which led to the calculation of fractal dimensions (D). The difference statistics method was used to calculate fractal dimensions. To obtain the images of asphaltene deposits on the surface, in micro scale size, a high pressure cell was designed. The condition for asphaltene precipitation in a solution of Asphaltene/Toluene/ Heptane was maintained by changing the pressure of the cell. Results showed that by increasing of pressure, the mica and glass surfaces tend to be altered to the oil wet conditions because of the increase in fractal dimension which is the representative of surface roughness. It was also observed that fractal dimension of asphaltene-deposited glass surface is more than the one for asphaltene-deposited mica surface at the end of experiment. Since number of nucleation- growth sites on mica surface are much more than those of glass surface thus asphaltene growth on mica surface is much more noticeable which can fill micro-asperities.