Laboratory study on the effect of salinity, surfactant type and concentration to recovery factor for carbonate rock

Abstract

The needs of petroleum as energy, have increasing while the oil production has depleting. Due to that needs, the method of Enhanced Oil Recovery (EOR) or in other hands as tertiary recovery (after primary recovery and secondary recovery) is being developed. EOR has many methods; one of the methods is chemical injection that consists of surfactant, alkaline and polymer. In this experiment, the author is using surfactant injection. The using of surfactant is to decrease the interfacial tension between oil and water, with the result is surfactant can displace oil through rock pores. This study will be discussing about the effect of salinity, surfactant types and surfactant concentrations on surfactant injection for carbonate rock. The surfactant types are Alpha Olefin Sulfonate (AOS) and Tween 20. The surfactant concentration varieties are 0,1%; 0,25%; 0,5%; 0,75% and 1%. Salinity varieties are 10.000 ppm; 15.000 ppm; 20.000 ppm and 25.000 ppm. From this study, it had determined that surfactant can displace the oil from rock pores based on the influence of salinity, surfactant concentrations and surfactant types to recovery factor. The determination of recovery factor will be using these methods; Amott apparatus (imbibition process) and injection using core holder and syringe pump. From experiments that have been done, the effect of surfactant injection on carbonate rocks is more optimal in core flooding process compared with imbibition process, with the recovery factor percentage is 57%. Core flooding process uses the external thrust, therefore the oil displacement with surfactant is more evenly and optimally.