The demand for a new solvent to treat oilsands was behind the purpose of this project; molecular dynamics simulation was used in this study. Supercritical water, supercritical carbon dioxide and other selected organic solvents in their supercritical state were studied. Meso-tetraphenyl porphyrin (H2TPP) and Octaethyl porphyrin (H2OEP) are the porphyrin model compounds and, 4’-Bis-(2-pyren-1-yl-ethyl)-[2, 2’] bipyridinyl (PBP) is the asphaltene model compound. A solubility parameter approach was used to infer the solubility of model compounds in the supercritical fluids. First, the solubility of water, carbon dioxide, 4 selected organic solvents, and the three model compounds were computed using molecular dynamics simulation and compared with experimental results. The computed solubility parameters showed that the model compounds would dissolve in supercritical water (22.5 MPa and 645-655 K) but exhibited no solubility in supercritical carbon dioxide.