فهرست نشریات علمی دسترسی آزاد ایران

Most of the reservoirs in Iran are carbonate reservoirs that spend the second half of their life cycle, requiring acid stimulation processes for improved production rates. Acidizing is a well and reservoir stimulation method used to increase oil and gas production from the fields due to its cost and efficiency. Acidizing of carbonate reservoirs is usually done in three stages: pre-flush, main acidizing, and post-flush. The pre-flush fluid is used to change the wettability of the rock from oil-wetting to water-wetting. In this work, we aim to identify the optimal pre-flush fluid using a CTAB surfactant to enhance the acidizing process. Initially, the porosity test is conducted on the carbonate cores, and then they are acidized using 15 wt% HCl. Then, the contact angle test is performed to determine the optimal concentration of surfactant and the optimal time. Finally, the cores that we placed in contact with the pre-flush fluid were positioned in the vicinity of the acidic solution to assess the effectiveness of the pre-flush fluid. A CTAB surfactant solution with a concentration of 500 ppm in seawater, and a duration of 120 minutes, reduced the contact angle from 125 to 42.574, and was determined as the optimal pre-flush fluid. Also, the combination of 15 wt% HCl with seawater had the best performance.