Asphaltene Deposition in Porous Media During Gas Injection

The precipitation and deposition of asphaltenes in porous media and their interactions with rock and fluids represent complex phenomena, which need to be investigated under dynamic flowing conditions. In this paper, experimental results are provided to determine the likelihood of asphaltene deposition problems on the dynamic displacement of heavy oil by natural gas in unconsolidated porous media. Dynamic tests carried out at reservoir conditions for asphaltene precipitation in porous media. Here the limestone rock material is a representative of porous media. Dynamic experiments showed a considerable increase in asphaltene deposition in the unconsolidated matrix during natural gas injection. The results show that increase in asphaltene deposition leads to pore plugging, porosity and absolute permeability reduction of the porous media. Irreducible water measurements show that natural gas-induced asphaltenes change the limestone wettability to oil-wet.