Eventually, the pressure that makes the oil and gas emerge decreases, and it must be maintained by the injection of water, chemicals, carbon dioxide, or other gases, such as nitrogen.
Pēc kāda laika spiediens naftas iegulā mazinās, un, lai to uzturētu, iegulā tiek iesūknēts ūdens, ogļskābā gāze, slāpeklis vai citas gāzes.