Sulfur and asphaltene deposition during CO₂ flooding of carbonate reservoirs

Simultaneous sulfur and asphaltene deposition in porous media as a result of CO₂ injection may significantly reduce the CO₂ flooding injectivity and create plugging problem and might affect the recovery efficiency of the process. Accurate assessment of sulfur and asphaltene deposition during CO₂ is critical information for the design of viable CO₂ flooding process. The main objective of this work is to investigate the simultaneous deposition of sulfur and asphaltene in the porous media during CO₂ flooding. To achieve this objective, the influences of water saturation, type of flooding process i.e. slug and continuous, CO ₂ injection rate, and permeability of the system on the oil recovery and the losses of sulfur and asphaltene in the reservoir rocks were investigated. Nine experiments were carried-out using one of UAE oil reservoirs crude oil. The results indicated that both sulfur and asphaltene were precipitated in the system and in general higher sulfur loses to the pores media as compared to asphaltene was observed. Copyrighl 2009., Society of Petroleum Engineers.