Asphaltene Deposition and Formation Damage During CO2/ Hydrocarbon Gas injection projects for Enhanced Oil Recovery (EOR)

Any EOR process can modify the flow and phase behavior of reservoir fluids , and rock properties . These modifications could lead to asphaltene precipitiation . Asphaltene deposition on formation is a serious problem during CO2 gas injection , and can cause porosity and permeability reduction in the reservoir , and plugging wellbore and piping in production facilities. the potential of asphaltene precipitationoccurring during primary production phase has been experienced in many reservoirs in the middle east . in the application of and EOR processes such as miscible/gas it is expected that the operation may face serious injectivity problems due to the manifestation of asphaltene prcipitation soon after the gas injection. in the planning of any gas injection EOR project the flocculation and deposition of asphaltene in porous media and their interation with rock and fluid represent complex phenomena which need to be investigated under dynamic flowing conditiions. in this presentation careful attention and a systematic approach will be presented for investigating asphatene precipitation problems during a gas injection project at the earliest stage of the planning . as once the asphaltene precipitation occurs it causes severe permeability and porosity reduction and wettability alteration, changing relative permeability in the reservoir and in severe cases plugging of the wellbore and surface facilities. preventative techniques and remedial measures such as chemical treatments and workover operations will be discussed.