Asphaltenes often precipitate and then deposit on the rock surfaces altering the wettability and plugging formation pores with a detrimental effect on relative permeability and oil production. This paper presents two different experimental techniques to study the effect of microemulsions in removing asphaltenes and crude oil from solid surfaces. The first technique is based on the use of microfluidics to visualize asphaltene residue deposition into model two dimensional (2D) porous media followed by application of a dilute microemulsion to wash off asphaltenes. Asphaltenes removal is quantified by analyzing images taken before and after microemulsion treatment using image analysis software. The second technique consists of shaken bottle tests to quantify the removal of heavy asphaltenic deposits from solid surfaces. The grains were coated with a heavy crude oil and then baked for 24 hours in an oven at 100C. These coated materials were treated with diluted microemulsion for 10 minutes and removal quantified. In both techniques, the diluted microemulsion removed a large amount of the asphaltenes deposited on the surface. The amount of wash off was strongly dependent on crude oil composition, microemulsion concentration and solvent type/content within the microemulsion. Both techniques can be used to effectively quantify removal of asphaltenes from solid surfaces. The ability of microemulsion in removing asphaltenes from rock surfaces has not previously been investigated. These results are expected to have a significant impact in completing and re- stimulating wells.

Asphaltenes wash off using terpene microemulsions

255th National Meeting (2018)

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