Reversibility of Asphaltene Deposition Under Dynamic Flow Conditions

Abstract

Occurrence of asphaltene deposition in production formation constitutes one of the most serious problems currently encountered in the petroleum industry in many areas of the world. Reversibility of asphaltene deposition causes crucial argument and controversy in laboratory research of the petroleum industry. A deeper understanding of this phenomenon is the key for treatment of the problem of asphaltene deposition. The major goals of this study were to investigate 1) asphaltene adsorption rate on carbonate rock surfaces under static condition, and 2) asphaltene deposition and its reversibility under dynamic flow conditions. For the sake of achieving these goals, two groups of experiments were undertaken. The first one measured asphaltene adsorption rate under static condition, while the second group was devoted to studying reversibility of asphaltene deposition under dynamic flow condition through actual porous medium. The results of the study indicated that the increase of aging time increases asphaltene adsorption on carbonate rock surfaces under static condition. However, the major part of asphaltene is adsorbed during the first 30 h of contact of oil with the rock surface. The results of dynamic flow experiments showed that asphaltene deposition is a continuous process causing permeability damage and is also partially reversible. Furthermore, the asphaltene deposition causes more damage in low permeability rock than one in higher permeability. The obtained results are expected to have important implications for better formulation of treatments of asphaltene deposition.