Adsorption study of acrylamide-tertiary-butyl sulfonate (ATBS)/ acrylamide copolymer in polymer flooding enhanced oil recovery (EOR) process

Polymer flood is known as the most important enhanced oil recovery technology due to its various advantageous and relatively cheaper price. However, it comes with associated problems of polymer adsorption that leads to injectivity loss. This work aims in studying various parameters that may affect the ATBS/ Acrylamide copolymer adsorption in a porous medium to optimize the polymer scheme. Synthetic D brine with D sand sample was mixed and tested in static and dynamic condition. These tests were conducted at room temperature and 90°C whereby the core flooding experiments were conducted with varied flowrate through Berea Sand Core sample. Results show that a higher brine salinity and a longer aging time leads to higher adsorption rate whereas adsorption static test conducted at replicated reservoir condition of 90°C resulted in lower adsorption capacity than at room temperature. Also, static adsorption was found to be higher than the dynamic adsorption due to the changes in the specific surface area and the extent of mechanical retention present in the dynamic core flood experiment. In conclusion, the type of polymer used in polymer flooding must be carefully chosen to serve the need for a specific reservoir condition so that the adsorption phenomenon is minimized.