RESEARCH OF INFLUENCE OF ASPHALTENE-RESIN SUBSTANCES INTO OIL ON THE FORMATION OF ASPHALTENE-PARAFFIN-RESIN DEPOSITION

Abstract

The completion phase of an oil field development is characterized by increased water cutting of well production, reservoir and bottom-hole pressures decline, growth of high molecular weight (HMW) components content in crude oil. These aspects make field operations more hazardous as they lead to formation of asphaltene-paraffin-resin deposition (APRD) on borehole walls and equipment. The impact of HMW components in crude oil and water-cut on pressure and temperature conditions of APRD and on its rate needs detailed study. This paper presents some results of the analysis of oil paraffin saturation point depending on asphaltene-resin substances (ARS) content under reservoir conditions. Dependence of the rate of APRD on a cold well walls and resin substances content in oil is studied. The results of experiments with low-resin and high-paraffin crude oil show that asphaltenes and resins in oil dispersion system can result in depressive effects. According to the results, asphaltene-resin substances are natural depressants, making the temperature of paraffin appearance in oil lower, and their properties depend on the base of oil. The results of the rate of APRD show that sedimentation stability of dry crude oil with increasing of ARS content remains almost stable and does not have any impact on deposition, whereas in experiments with wet crude oil increased ARS content leads to significantly higher deposition.