Abstract:

Gas deasphaltizing is one of the main factors to generate the asphalt mattress or to decrease oil API gravity in oil reservoir. Taking Palaeogene oil reservoir in ME basin of Sudan as an example, on the basis of analysis of the geologic characteristics of reservoir, physical properties and geochemical characteristics of crude oil, components of solution gas, this paper indicated the positive correlation betweenCO₂content and API gravity of crude oil, and deduced that the lower API gravity of crude oil should be deasphaltized by CO₂ washing or invasion, which was validated by Raman spectroscopy analysis of oilbearing inclusions;and the resource of biogeneticCO₂could be derived from adjacent deep faults which penetrated lower crust or upper mantle.

Key words: gas deasphaltizing, carbon dioxide, solution gas, heavy oil pool, Sudan