THE STUDY OF THE EFFECT OF TEMPERATURE AND PH VALUE ON ADSORPTION CHARACTERISTICS OF UREA BASED SACRIFICIAL AGENT IN CLAY MINERALS

Abstract

The Enhanced Oil Recovery (EOR) process has grown within the time oil exploration was conducted, and many recovery methods were invented to maximize production. One of the promising recovery techniques is carbon dioxide (CO2) flooding. However, CO2 flooding has its disadvantages where due to different mobility and heterogeneity between CO2 and reservoir, the sweep efficiency is reduced because of gas channelling and viscous fingering. Thus, the application of surfactant is introduced to solve the problem. But, by using surfactants in CO2 flooding, loss of surfactant to the formation is observed. Due to this setback, the cost of the EOR process increased significantly as more surfactants must be injected due to the loss. To reduce surfactant loss, sacrificial agents are introduced within the application of surfactant in CO2 flooding. The sacrificial agent would be adsorbed onto the clay minerals instead of surfactants. However, the application of sacrificial agent needs to be optimized to ensure a more cost-effective process. Therefore, this study, the adsorption rate of urea-based sacrificial agent in montmorillonite and kaolinite was tested under different pH values and temperatures using a UV-Vis spectrometer. Through the adsorption test, it is observed that the adsorption rate of urea is higher in montmorillonite than in kaolinite. The adsorption rate of urea in montmorillonite and kaolinite are optimized in high-temperature alkaline environment with 1.50 mg/g and 1.46 mg/g of urea adsorbed, respectively.Keywords: CO2 flooding, montmorillonite, kaolinite, sacrificial agent, urea, adsorption rate