The declining in production can occur because wells that have been producing for a long time are no longer able to lift oil to the surface in primary and secondary ways. Therefore. tertiary methods such as chemical injection like polymer flooding were carried out. Polymers commonly used in flooding polymers are divided into three namely synthetic polymers. https://www.roneverhart.com/Behringer-UL-1000G2-Wireless-In-Ear-Monitoring-System-US-584-to-608-MHz-p31393/